dlib from github, version=19.24

dlib/array.h

+// Copyright (C) 2003  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_ARRAy_
+#define DLIB_ARRAy_
+
+#include "array/array_kernel.h"
+#include "array/array_tools.h"
+
+#endif // DLIB_ARRAy_
+

dlib/array/array_kernel.h

+// Copyright (C) 2003  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_ARRAY_KERNEl_2_
+#define DLIB_ARRAY_KERNEl_2_
+
+#include "array_kernel_abstract.h"
+#include "../interfaces/enumerable.h"
+#include "../algs.h"
+#include "../serialize.h"
+#include "../sort.h"
+#include "../is_kind.h"
+
+namespace dlib
+{
+
+    template <
+        typename T,
+        typename mem_manager = default_memory_manager 
+        >
+    class array : public enumerable<T>
+    {
+
+        /*!
+            INITIAL VALUE
+                - array_size == 0    
+                - max_array_size == 0
+                - array_elements == 0
+                - pos == 0
+                - last_pos == 0
+                - _at_start == true
+
+            CONVENTION
+                - array_size == size() 
+                - max_array_size == max_size() 
+                - if (max_array_size > 0)
+                    - array_elements == pointer to max_array_size elements of type T
+                - else
+                    - array_elements == 0
+
+                - if (array_size > 0) 
+                    - last_pos == array_elements + array_size - 1
+                - else
+                    - last_pos == 0
+
+
+                - at_start() == _at_start 
+                - current_element_valid() == pos != 0
+                - if (current_element_valid()) then
+                    - *pos == element()
+        !*/
+
+    public:
+
+        // These typedefs are here for backwards compatibility with old versions of dlib.
+        typedef array kernel_1a;
+        typedef array kernel_1a_c;
+        typedef array kernel_2a;
+        typedef array kernel_2a_c;
+        typedef array sort_1a;
+        typedef array sort_1a_c;
+        typedef array sort_1b;
+        typedef array sort_1b_c;
+        typedef array sort_2a;
+        typedef array sort_2a_c;
+        typedef array sort_2b;
+        typedef array sort_2b_c;
+        typedef array expand_1a;
+        typedef array expand_1a_c;
+        typedef array expand_1b;
+        typedef array expand_1b_c;
+        typedef array expand_1c;
+        typedef array expand_1c_c;
+        typedef array expand_1d;
+        typedef array expand_1d_c;
+
+
+
+
+        typedef T type;
+        typedef T value_type;
+        typedef mem_manager mem_manager_type;
+
+        array (
+        ) :
+            array_size(0),
+            max_array_size(0),
+            array_elements(0),
+            pos(0),
+            last_pos(0),
+            _at_start(true)
+        {}
+
+        array(const array&) = delete;
+        array& operator=(array&) = delete; 
+
+        array(
+            array&& item
+        ) : array()
+        {
+            swap(item);
+        }
+
+        array& operator=(
+            array&& item
+        )
+        {
+            swap(item);
+            return *this;
+        }
+
+        explicit array (
+            size_t new_size
+        ) :
+            array_size(0),
+            max_array_size(0),
+            array_elements(0),
+            pos(0),
+            last_pos(0),
+            _at_start(true)
+        {
+            resize(new_size);
+        }
+
+        ~array (
+        ); 
+
+        void clear (
+        );
+
+        inline const T& operator[] (
+            size_t pos
+        ) const;
+
+        inline T& operator[] (
+            size_t pos
+        );
+
+        void set_size (
+            size_t size
+        );
+
+        inline size_t max_size(
+        ) const;
+
+        void set_max_size(
+            size_t max
+        );
+
+        void swap (
+            array& item
+        );
+
+        // functions from the enumerable interface
+        inline size_t size (
+        ) const;
+
+        inline bool at_start (
+        ) const;
+
+        inline void reset (
+        ) const;
+
+        bool current_element_valid (
+        ) const;
+
+        inline const T& element (
+        ) const;
+
+        inline T& element (
+        );
+
+        bool move_next (
+        ) const;
+
+        void sort (
+        );
+
+        void resize (
+            size_t new_size
+        );
+
+        const T& back (
+        ) const;
+
+        T& back (
+        );
+
+        void pop_back (
+        );
+
+        void pop_back (
+            T& item
+        );
+
+        void push_back (
+            T& item
+        );
+
+        void push_back (
+            T&& item
+        );
+
+        typedef T* iterator;
+        typedef const T* const_iterator;
+        iterator                begin()                         { return array_elements; }
+        const_iterator          begin() const                   { return array_elements; }
+        iterator                end()                           { return array_elements+array_size; }
+        const_iterator          end() const                     { return array_elements+array_size; }
+
+    private:
+
+        typename mem_manager::template rebind<T>::other pool;
+
+        // data members
+        size_t array_size;
+        size_t max_array_size;
+        T* array_elements;
+
+        mutable T* pos;
+        T* last_pos;
+        mutable bool _at_start;
+
+    };
+
+    template <
+        typename T,
+        typename mem_manager 
+        >
+    inline void swap (
+        array<T,mem_manager>& a, 
+        array<T,mem_manager>& b 
+    ) { a.swap(b); }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void serialize (
+        const array<T,mem_manager>& item,  
+        std::ostream& out
+    )
+    {
+        try
+        {
+            serialize(item.max_size(),out);
+            serialize(item.size(),out);
+
+            for (size_t i = 0; i < item.size(); ++i)
+                serialize(item[i],out);
+        }
+        catch (serialization_error& e)
+        { 
+            throw serialization_error(e.info + "\n   while serializing object of type array"); 
+        }
+    }
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void deserialize (
+        array<T,mem_manager>& item,  
+        std::istream& in
+    )
+    {
+        try
+        {
+            size_t max_size, size;
+            deserialize(max_size,in);
+            deserialize(size,in);
+            item.set_max_size(max_size);
+            item.set_size(size);
+            for (size_t i = 0; i < size; ++i)
+                deserialize(item[i],in);
+        }
+        catch (serialization_error& e)
+        { 
+            item.clear();
+            throw serialization_error(e.info + "\n   while deserializing object of type array"); 
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+// member function definitions
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    array<T,mem_manager>::
+    ~array (
+    )
+    {
+        if (array_elements)
+        {
+            pool.deallocate_array(array_elements);
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void array<T,mem_manager>::
+    clear (
+    )
+    {
+        reset();
+        last_pos = 0;
+        array_size = 0;
+        if (array_elements)
+        {
+            pool.deallocate_array(array_elements);
+        }
+        array_elements = 0;
+        max_array_size = 0;
+
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    const T& array<T,mem_manager>::
+    operator[] (
+        size_t pos
+    ) const
+    {
+        // make sure requires clause is not broken
+        DLIB_ASSERT( pos < this->size() , 
+            "\tconst T& array::operator[]"
+            << "\n\tpos must < size()" 
+            << "\n\tpos: " << pos 
+            << "\n\tsize(): " << this->size()
+            << "\n\tthis: " << this
+            );
+
+        return array_elements[pos];
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    T& array<T,mem_manager>::
+    operator[] (
+        size_t pos
+    ) 
+    {
+        // make sure requires clause is not broken
+        DLIB_ASSERT( pos < this->size() , 
+            "\tT& array::operator[]"
+            << "\n\tpos must be < size()" 
+            << "\n\tpos: " << pos 
+            << "\n\tsize(): " << this->size()
+            << "\n\tthis: " << this
+            );
+
+        return array_elements[pos];
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void array<T,mem_manager>::
+    set_size (
+        size_t size
+    )
+    {
+        // make sure requires clause is not broken
+        DLIB_CASSERT(( size <= this->max_size() ),
+            "\tvoid array::set_size"
+            << "\n\tsize must be <= max_size()"
+            << "\n\tsize: " << size 
+            << "\n\tmax size: " << this->max_size()
+            << "\n\tthis: " << this
+            );
+
+        reset();
+        array_size = size;
+        if (size > 0)
+            last_pos = array_elements + size - 1;
+        else
+            last_pos = 0;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    size_t array<T,mem_manager>::
+    size (
+    ) const
+    {
+        return array_size;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void array<T,mem_manager>::
+    set_max_size(
+        size_t max
+    )
+    {
+        reset();
+        array_size = 0;
+        last_pos = 0;
+        if (max != 0)
+        {
+            // if new max size is different
+            if (max != max_array_size)
+            {
+                if (array_elements)
+                {
+                    pool.deallocate_array(array_elements);
+                }
+                // try to get more memroy
+                try { array_elements = pool.allocate_array(max); }
+                catch (...) { array_elements = 0;  max_array_size = 0; throw; }
+                max_array_size = max;
+            }
+
+        }
+        // if the array is being made to be zero
+        else
+        {
+            if (array_elements)
+                pool.deallocate_array(array_elements);
+            max_array_size = 0;
+            array_elements = 0;
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    size_t array<T,mem_manager>::
+    max_size (
+    ) const
+    {
+        return max_array_size;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void array<T,mem_manager>::
+    swap (
+        array<T,mem_manager>& item
+    )
+    {
+        auto             array_size_temp        = item.array_size;
+        auto             max_array_size_temp    = item.max_array_size;
+        T*               array_elements_temp    = item.array_elements;
+
+        item.array_size         = array_size;
+        item.max_array_size     = max_array_size;
+        item.array_elements     = array_elements;
+
+        array_size        = array_size_temp;
+        max_array_size    = max_array_size_temp;
+        array_elements    = array_elements_temp;
+
+        exchange(_at_start,item._at_start);
+        exchange(pos,item.pos);
+        exchange(last_pos,item.last_pos);
+        pool.swap(item.pool);
+    }
+
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+//           enumerable function definitions
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    bool array<T,mem_manager>::
+    at_start (
+    ) const
+    {
+        return _at_start;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void array<T,mem_manager>::
+    reset (
+    ) const
+    {
+        _at_start = true;
+        pos = 0;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    bool array<T,mem_manager>::
+    current_element_valid (
+    ) const
+    {
+        return pos != 0;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    const T& array<T,mem_manager>::
+    element (
+    ) const
+    {
+        // make sure requires clause is not broken
+        DLIB_ASSERT(this->current_element_valid(),
+            "\tconst T& array::element()"
+            << "\n\tThe current element must be valid if you are to access it."
+            << "\n\tthis: " << this
+            );
+
+        return *pos;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    T& array<T,mem_manager>::
+    element (
+    )
+    {
+        // make sure requires clause is not broken
+        DLIB_ASSERT(this->current_element_valid(),
+            "\tT& array::element()"
+            << "\n\tThe current element must be valid if you are to access it."
+            << "\n\tthis: " << this
+            );
+
+        return *pos;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    bool array<T,mem_manager>::
+    move_next (
+    ) const
+    {
+        if (!_at_start)
+        {
+            if (pos < last_pos)
+            {
+                ++pos;
+                return true;
+            }
+            else
+            {
+                pos = 0;
+                return false;
+            }
+        }
+        else
+        {
+            _at_start = false;
+            if (array_size > 0)
+            {
+                pos = array_elements;
+                return true;
+            }
+            else
+            {
+                return false;
+            }
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+//                              Yet more functions
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void array<T,mem_manager>::
+    sort (
+    )
+    {
+        if (this->size() > 1)
+        {
+            // call the quick sort function for arrays that is in algs.h
+            dlib::qsort_array(*this,0,this->size()-1);
+        }
+        this->reset();
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void array<T,mem_manager>::
+    resize (
+        size_t new_size
+    )
+    {
+        if (this->max_size() < new_size)
+        {
+            array temp;
+            temp.set_max_size(new_size);
+            temp.set_size(new_size);
+            for (size_t i = 0; i < this->size(); ++i)
+            {
+                exchange((*this)[i],temp[i]);
+            }
+            temp.swap(*this);
+        }
+        else
+        {
+            this->set_size(new_size);
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    T& array<T,mem_manager>::
+    back (
+    ) 
+    {
+        // make sure requires clause is not broken
+        DLIB_ASSERT( this->size() > 0 , 
+                      "\tT& array::back()"
+                      << "\n\tsize() must be bigger than 0" 
+                      << "\n\tsize(): " << this->size()
+                      << "\n\tthis:   " << this
+        );
+
+        return (*this)[this->size()-1];
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    const T& array<T,mem_manager>::
+    back (
+    ) const
+    {
+        // make sure requires clause is not broken
+        DLIB_ASSERT( this->size() > 0 , 
+                      "\tconst T& array::back()"
+                      << "\n\tsize() must be bigger than 0" 
+                      << "\n\tsize(): " << this->size()
+                      << "\n\tthis:   " << this
+        );
+
+        return (*this)[this->size()-1];
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void array<T,mem_manager>::
+    pop_back (
+        T& item
+    ) 
+    {
+        // make sure requires clause is not broken
+        DLIB_ASSERT( this->size() > 0 , 
+                      "\tvoid array::pop_back()"
+                      << "\n\tsize() must be bigger than 0" 
+                      << "\n\tsize(): " << this->size()
+                      << "\n\tthis:   " << this
+        );
+
+        exchange(item,(*this)[this->size()-1]);
+        this->set_size(this->size()-1);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void array<T,mem_manager>::
+    pop_back (
+    ) 
+    {
+        // make sure requires clause is not broken
+        DLIB_ASSERT( this->size() > 0 , 
+                      "\tvoid array::pop_back()"
+                      << "\n\tsize() must be bigger than 0" 
+                      << "\n\tsize(): " << this->size()
+                      << "\n\tthis:   " << this
+        );
+
+        this->set_size(this->size()-1);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void array<T,mem_manager>::
+    push_back (
+        T& item
+    ) 
+    {
+        if (this->max_size() == this->size())
+        {
+            // double the size of the array
+            array temp;
+            temp.set_max_size(this->size()*2 + 1);
+            temp.set_size(this->size()+1);
+            for (size_t i = 0; i < this->size(); ++i)
+            {
+                exchange((*this)[i],temp[i]);
+            }
+            exchange(item,temp[temp.size()-1]);
+            temp.swap(*this);
+        }
+        else
+        {
+            this->set_size(this->size()+1);
+            exchange(item,(*this)[this->size()-1]);
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void array<T,mem_manager>::
+    push_back (
+        T&& item
+    ) { push_back(item); }
+
+// ----------------------------------------------------------------------------------------
+
+    template <typename T, typename MM>
+    struct is_array <array<T,MM> >  
+    {
+        const static bool value = true;
+    };
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_ARRAY_KERNEl_2_
+

dlib/array/array_kernel_abstract.h

+// Copyright (C) 2003  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#undef DLIB_ARRAY_KERNEl_ABSTRACT_
+#ifdef DLIB_ARRAY_KERNEl_ABSTRACT_
+
+#include "../interfaces/enumerable.h"
+#include "../serialize.h"
+#include "../algs.h"
+
+namespace dlib
+{
+
+    template <
+        typename T,
+        typename mem_manager = default_memory_manager 
+        >
+    class array : public enumerable<T>
+    {
+
+        /*!
+            REQUIREMENTS ON T
+                T must have a default constructor.
+
+            REQUIREMENTS ON mem_manager
+                must be an implementation of memory_manager/memory_manager_kernel_abstract.h or
+                must be an implementation of memory_manager_global/memory_manager_global_kernel_abstract.h or
+                must be an implementation of memory_manager_stateless/memory_manager_stateless_kernel_abstract.h 
+                mem_manager::type can be set to anything.
+
+            POINTERS AND REFERENCES TO INTERNAL DATA
+                front(), back(), swap(), max_size(), set_size(), and operator[] 
+                functions do not invalidate pointers or references to internal data.
+                All other functions have no such guarantee.
+
+            INITIAL VALUE
+                size() == 0    
+                max_size() == 0
+
+            ENUMERATION ORDER
+                The enumerator will iterate over the elements of the array in the
+                order (*this)[0], (*this)[1], (*this)[2], ...
+
+            WHAT THIS OBJECT REPRESENTS
+                This object represents an ordered 1-dimensional array of items, 
+                each item is associated with an integer value.  The items are 
+                numbered from 0 though size() - 1 and the operator[] functions 
+                run in constant time.  
+
+                Also note that unless specified otherwise, no member functions
+                of this object throw exceptions.
+        !*/
+        
+        public:
+
+            typedef T type;
+            typedef T value_type;
+            typedef mem_manager mem_manager_type;
+
+            array (
+            );
+            /*!
+                ensures 
+                    - #*this is properly initialized
+                throws
+                    - std::bad_alloc or any exception thrown by T's constructor
+            !*/
+
+            explicit array (
+                size_t new_size
+            );
+            /*!
+                ensures 
+                    - #*this is properly initialized
+                    - #size() == new_size
+                    - #max_size() == new_size
+                    - All elements of the array will have initial values for their type.
+                throws
+                    - std::bad_alloc or any exception thrown by T's constructor
+            !*/
+
+            ~array (
+            ); 
+            /*!
+                ensures
+                    - all memory associated with *this has been released
+            !*/
+
+            array(
+                array&& item
+            );
+            /*!
+                ensures
+                    - move constructs *this from item.  Therefore, the state of item is
+                      moved into *this and #item has a valid but unspecified state.
+            !*/
+
+            array& operator=(
+                array&& item
+            );
+            /*!
+                ensures
+                    - move assigns *this from item.  Therefore, the state of item is
+                      moved into *this and #item has a valid but unspecified state.
+                    - returns a reference to #*this
+            !*/
+
+            void clear (
+            );
+            /*!
+                ensures
+                    - #*this has its initial value
+                throws
+                    - std::bad_alloc or any exception thrown by T's constructor
+                        if this exception is thrown then the array object is unusable 
+                        until clear() is called and succeeds
+            !*/
+
+            const T& operator[] (
+                size_t pos
+            ) const;
+            /*!
+                requires
+                    - pos < size()
+                ensures
+                    - returns a const reference to the element at position pos
+            !*/
+            
+            T& operator[] (
+                size_t pos
+            );
+            /*!
+                requires
+                    - pos < size()
+                ensures
+                    - returns a non-const reference to the element at position pos
+            !*/
+
+            void set_size (
+                size_t size
+            );
+            /*!
+                requires
+                    - size <= max_size()
+                ensures
+                    - #size() == size
+                    - any element with index between 0 and size - 1 which was in the 
+                      array before the call to set_size() retains its value and index.
+                      All other elements have undetermined (but valid for their type) 
+                      values.  (e.g. this object might buffer old T objects and reuse 
+                      them without reinitializing them between calls to set_size())
+                    - #at_start() == true
+                throws
+                    - std::bad_alloc or any exception thrown by T's constructor
+                        may throw this exception if there is not enough memory and 
+                        if it does throw then the call to set_size() has no effect    
+            !*/
+
+            size_t max_size(
+            ) const;
+            /*!
+                ensures
+                    - returns the maximum size of *this
+            !*/
+
+            void set_max_size(
+                size_t max
+            );
+            /*!
+                ensures
+                    - #max_size() == max
+                    - #size() == 0
+                    - #at_start() == true
+                throws
+                    - std::bad_alloc or any exception thrown by T's constructor
+                        may throw this exception if there is not enough 
+                        memory and if it does throw then max_size() == 0    
+            !*/
+
+            void swap (
+                array<T>& item
+            );
+            /*!
+                ensures
+                    - swaps *this and item
+            !*/ 
+            
+            void sort (
+            );
+            /*!
+                requires
+                    - T must be a type with that is comparable via operator<
+                ensures
+                    - for all elements in #*this the ith element is <= the i+1 element
+                    - #at_start() == true
+                throws
+                    - std::bad_alloc or any exception thrown by T's constructor
+                        data may be lost if sort() throws
+            !*/
+
+            void resize (
+                size_t new_size
+            );
+            /*!
+                ensures
+                    - #size() == new_size
+                    - #max_size() == max(new_size,max_size())
+                    - for all i < size() && i < new_size:
+                        - #(*this)[i] == (*this)[i]
+                          (i.e. All the original elements of *this which were at index
+                          values less than new_size are unmodified.)
+                    - for all valid i >= size():
+                        - #(*this)[i] has an undefined value
+                          (i.e. any new elements of the array have an undefined value)
+                throws
+                    - std::bad_alloc or any exception thrown by T's constructor.
+                       If an exception is thrown then it has no effect on *this.
+            !*/
+
+            
+            const T& back (
+            ) const;
+            /*!
+                requires
+                    - size() != 0
+                ensures
+                    - returns a const reference to (*this)[size()-1]
+            !*/
+
+            T& back (
+            );
+            /*!
+                requires
+                    - size() != 0
+                ensures
+                    - returns a non-const reference to (*this)[size()-1]
+            !*/
+
+            void pop_back (
+                T& item
+            );
+            /*!
+                requires
+                    - size() != 0
+                ensures
+                    - #size() == size() - 1
+                    - swaps (*this)[size()-1] into item
+                    - All elements with an index less than size()-1 are 
+                      unmodified by this operation.
+            !*/
+
+            void pop_back (
+            );
+            /*!
+                requires
+                    - size() != 0
+                ensures
+                    - #size() == size() - 1
+                    - All elements with an index less than size()-1 are 
+                      unmodified by this operation.
+            !*/
+
+            void push_back (
+                T& item
+            );
+            /*!
+                ensures
+                    - #size() == size()+1
+                    - swaps item into (*this)[#size()-1] 
+                    - #back() == item
+                    - #item has some undefined value (whatever happens to 
+                      get swapped out of the array)
+                throws
+                    - std::bad_alloc or any exception thrown by T's constructor.
+                       If an exception is thrown then it has no effect on *this.
+            !*/
+
+            void push_back (T&& item) { push_back(item); }
+            /*!
+                enable push_back from rvalues 
+            !*/
+
+            typedef T* iterator;
+            typedef const T* const_iterator;
+
+            iterator begin(
+            );
+            /*!
+                ensures
+                    - returns an iterator that points to the first element in this array or
+                      end() if the array is empty.
+            !*/
+
+            const_iterator begin(
+            ) const;
+            /*!
+                ensures
+                    - returns a const iterator that points to the first element in this
+                      array or end() if the array is empty.
+            !*/
+
+            iterator end(
+            );
+            /*!
+                ensures
+                    - returns an iterator that points to one past the end of the array.
+            !*/
+
+            const_iterator end(
+            ) const;
+            /*!
+                ensures
+                    - returns a const iterator that points to one past the end of the
+                      array.
+            !*/
+
+        private:
+
+            // restricted functions
+            array(array<T>&);        // copy constructor
+            array<T>& operator=(array<T>&);    // assignment operator        
+
+    };
+
+    template <
+        typename T
+        >
+    inline void swap (
+        array<T>& a, 
+        array<T>& b 
+    ) { a.swap(b); }
+    /*!
+        provides a global swap function
+    !*/
+
+    template <
+        typename T
+        >
+    void serialize (
+        const array<T>& item, 
+        std::ostream& out 
+    );   
+    /*!
+        provides serialization support 
+    !*/
+
+    template <
+        typename T 
+        >
+    void deserialize (
+        array<T>& item, 
+        std::istream& in
+    );   
+    /*!
+        provides deserialization support 
+    !*/
+
+}
+
+#endif // DLIB_ARRAY_KERNEl_ABSTRACT_
+

dlib/array/array_tools.h

+// Copyright (C) 2013  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_ARRAY_tOOLS_H_
+#define DLIB_ARRAY_tOOLS_H_
+
+#include "../assert.h"
+#include "array_tools_abstract.h"
+
+namespace dlib
+{
+    template <typename T>
+    void split_array (
+        T& a,
+        T& b,
+        double frac
+    )
+    {
+        // make sure requires clause is not broken
+        DLIB_ASSERT(0 <= frac && frac <= 1,
+            "\t void split_array()"
+            << "\n\t frac must be between 0 and 1."
+            << "\n\t frac: " << frac
+            );
+
+        const unsigned long asize = static_cast<unsigned long>(a.size()*frac);
+        const unsigned long bsize = a.size()-asize;
+
+        b.resize(bsize);
+        for (unsigned long i = 0; i < b.size(); ++i)
+        {
+            swap(b[i], a[i+asize]);
+        }
+        a.resize(asize);
+    }
+}
+
+#endif // DLIB_ARRAY_tOOLS_H_
+

dlib/array/array_tools_abstract.h

+// Copyright (C) 2013  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#undef DLIB_ARRAY_tOOLS_ABSTRACT_H_
+#ifdef DLIB_ARRAY_tOOLS_ABSTRACT_H_
+
+#include "array_kernel_abstract.h"
+
+namespace dlib
+{
+    template <typename T>
+    void split_array (
+        T& a,
+        T& b,
+        double frac
+    );
+    /*!
+        requires
+            - 0 <= frac <= 1
+            - T must be an array type such as dlib::array or std::vector
+        ensures
+            - This function takes the elements of a and splits them into two groups.  The
+              first group remains in a and the second group is put into b.  The ordering of
+              elements in a is preserved.  In particular, concatenating #a with #b will
+              reproduce the original contents of a.
+            - The elements in a are moved around using global swap().  So they must be
+              swappable, but do not need to be copyable.
+            - #a.size() == floor(a.size()*frac)
+            - #b.size() == a.size()-#a.size()
+    !*/
+}
+
+#endif // DLIB_ARRAY_tOOLS_ABSTRACT_H_
+

dlib/array2d.h

+// Copyright (C) 2006  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_ARRAY2d_ 
+#define DLIB_ARRAY2d_
+
+
+#include "array2d/array2d_kernel.h"
+#include "array2d/serialize_pixel_overloads.h"
+#include "array2d/array2d_generic_image.h"
+
+#endif // DLIB_ARRAY2d_
+

dlib/array2d/array2d_generic_image.h

+// Copyright (C) 2014  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_ARRAY2D_GENERIC_iMAGE_Hh_
+#define DLIB_ARRAY2D_GENERIC_iMAGE_Hh_
+
+#include "array2d_kernel.h"
+#include "../image_processing/generic_image.h"
+
+namespace dlib
+{
+    template <typename T, typename mm>
+    struct image_traits<array2d<T,mm> >
+    {
+        typedef T pixel_type;
+    };
+    template <typename T, typename mm>
+    struct image_traits<const array2d<T,mm> >
+    {
+        typedef T pixel_type;
+    };
+
+    template <typename T, typename mm>
+    inline long num_rows( const array2d<T,mm>& img) { return img.nr(); }
+    template <typename T, typename mm>
+    inline long num_columns( const array2d<T,mm>& img) { return img.nc(); }
+
+    template <typename T, typename mm>
+    inline void set_image_size(
+        array2d<T,mm>& img,
+        long rows,
+        long cols 
+    ) { img.set_size(rows,cols); }
+
+    template <typename T, typename mm>
+    inline void* image_data(
+        array2d<T,mm>& img
+    )
+    {
+        if (img.size() != 0)
+            return &img[0][0];
+        else
+            return 0;
+    }
+
+    template <typename T, typename mm>
+    inline const void* image_data(
+        const array2d<T,mm>& img
+    )
+    {
+        if (img.size() != 0)
+            return &img[0][0];
+        else
+            return 0;
+    }
+
+    template <typename T, typename mm>
+    inline long width_step(
+        const array2d<T,mm>& img
+    ) 
+    { 
+        return img.width_step(); 
+    }
+
+}
+
+#endif // DLIB_ARRAY2D_GENERIC_iMAGE_Hh_
+

dlib/array2d/array2d_kernel.h

+// Copyright (C) 2006  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_ARRAY2D_KERNEl_1_
+#define DLIB_ARRAY2D_KERNEl_1_
+
+#include "array2d_kernel_abstract.h"
+#include "../algs.h"
+#include "../interfaces/enumerable.h"
+#include "../serialize.h"
+#include "../geometry/rectangle.h"
+
+namespace dlib
+{
+    template <
+        typename T,
+        typename mem_manager = default_memory_manager
+        >
+    class array2d : public enumerable<T>
+    {
+
+        /*!
+            INITIAL VALUE
+                - nc_ == 0 
+                - nr_ == 0 
+                - data == 0 
+                - at_start_ == true
+                - cur == 0
+                - last == 0
+
+            CONVENTION
+                - nc_ == nc() 
+                - nr_ == nc() 
+                - if (data != 0) then
+                    - last == a pointer to the last element in the data array
+                    - data == pointer to an array of nc_*nr_ T objects 
+                - else
+                    - nc_ == 0
+                    - nr_ == 0
+                    - data == 0
+                    - last == 0
+
+
+                - nr_ * nc_ == size()
+                - if (cur == 0) then
+                    - current_element_valid() == false
+                - else 
+                    - current_element_valid() == true
+                    - *cur == element()
+
+                - at_start_ == at_start()      
+        !*/
+
+
+        class row_helper;
+    public:
+
+        // These typedefs are here for backwards compatibility with older versions of dlib.
+        typedef array2d kernel_1a;
+        typedef array2d kernel_1a_c;
+         
+        typedef T type;
+        typedef mem_manager mem_manager_type;
+        typedef T*          iterator;       
+        typedef const T*    const_iterator; 
+
+
+        // -----------------------------------
+
+        class row 
+        {
+            /*!
+                CONVENTION
+                    - nc_ == nc()
+                    - for all x < nc_:
+                        - (*this)[x] == data[x]
+            !*/
+
+            friend class array2d<T,mem_manager>;
+            friend class row_helper;
+
+        public:
+            long nc (
+            ) const { return nc_; }
+
+            const T& operator[] (
+                long column
+            ) const 
+            { 
+                // make sure requires clause is not broken
+                DLIB_ASSERT(column < nc() && column >= 0,
+                    "\tconst T& array2d::operator[](long column) const"
+                    << "\n\tThe column index given must be less than the number of columns."
+                    << "\n\tthis:    " << this
+                    << "\n\tcolumn:  " << column 
+                    << "\n\tnc(): " << nc()
+                );
+
+                return data[column]; 
+            }
+
+            T& operator[] (
+                long column
+            ) 
+            { 
+                // make sure requires clause is not broken
+                DLIB_ASSERT(column < nc() && column >= 0,
+                    "\tT& array2d::operator[](long column)"
+                    << "\n\tThe column index given must be less than the number of columns."
+                    << "\n\tthis:    " << this
+                    << "\n\tcolumn:  " << column 
+                    << "\n\tnc(): " << nc()
+                );
+
+                return data[column]; 
+            }
+
+        private:
+
+            row(T* data_, long cols) : data(data_), nc_(cols) {}
+            row(row&& r) = default;
+            row& operator=(row&& r) = default;
+
+            T* data = nullptr;
+            long nc_ = 0;
+
+
+            // restricted functions
+            row(const row&) = delete;
+            row& operator=(const row&) = delete;
+        };
+
+        // -----------------------------------
+
+        array2d (
+        ) : 
+            data(0),
+            nc_(0),
+            nr_(0),
+            cur(0),
+            last(0),
+            at_start_(true)
+        {
+        }
+
+        array2d(
+            long rows,
+            long cols
+        ) : 
+            data(0),
+            nc_(0),
+            nr_(0),
+            cur(0),
+            last(0),
+            at_start_(true)
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT((cols >= 0 && rows >= 0),
+                        "\t array2d::array2d(long rows, long cols)"
+                        << "\n\t The array2d can't have negative rows or columns."
+                        << "\n\t this: " << this
+                        << "\n\t cols: " << cols 
+                        << "\n\t rows: " << rows 
+            );
+
+            set_size(rows,cols);
+        }
+
+        array2d(const array2d&) = delete;        // copy constructor
+        array2d& operator=(const array2d&) = delete;    // assignment operator
+
+#ifdef DLIB_HAS_RVALUE_REFERENCES
+        array2d(array2d&& item) : array2d()
+        {
+            swap(item);
+        }
+
+        array2d& operator= (
+            array2d&& rhs
+        )
+        {
+            swap(rhs);
+            return *this;
+        }
+#endif
+
+        virtual ~array2d (
+        ) { clear(); }
+
+        long nc (
+        ) const { return nc_; }
+
+        long nr (
+        ) const { return nr_; }
+
+        row operator[] (
+            long row_
+        ) 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT(row_ < nr() && row_ >= 0,
+                "\trow array2d::operator[](long row_)"
+                << "\n\tThe row index given must be less than the number of rows."
+                << "\n\tthis:     " << this
+                << "\n\trow_:      " << row_ 
+                << "\n\tnr(): " << nr()
+                );
+
+            return row(data+row_*nc_, nc_);
+        }
+
+        const row operator[] (
+            long row_
+        ) const 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT(row_ < nr() && row_ >= 0,
+                "\tconst row array2d::operator[](long row_) const"
+                << "\n\tThe row index given must be less than the number of rows."
+                << "\n\tthis:     " << this
+                << "\n\trow_:      " << row_ 
+                << "\n\tnr(): " << nr()
+            );
+
+            return row(data+row_*nc_, nc_);
+        }
+
+        void swap (
+            array2d& item
+        )
+        {
+            exchange(data,item.data);
+            exchange(nr_,item.nr_);
+            exchange(nc_,item.nc_);
+            exchange(at_start_,item.at_start_);
+            exchange(cur,item.cur);
+            exchange(last,item.last);
+            pool.swap(item.pool);
+        }
+
+        void clear (
+        )
+        {
+            if (data != 0)
+            {
+                pool.deallocate_array(data);
+                nc_ = 0;
+                nr_ = 0;
+                data = 0;
+                at_start_ = true;
+                cur = 0;
+                last = 0;
+            }
+        }
+
+        void set_size (
+            long rows,
+            long cols
+        );
+
+        bool at_start (
+        ) const { return at_start_; }
+
+        void reset (
+        ) const { at_start_ = true; cur = 0; }
+
+        bool current_element_valid (
+        ) const { return (cur != 0); }
+
+        const T& element (
+        ) const 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT(current_element_valid() == true,
+                "\tconst T& array2d::element()()"
+                << "\n\tYou can only call element() when you are at a valid one."
+                << "\n\tthis:    " << this
+            );
+
+            return *cur; 
+        }
+
+        T& element (
+        ) 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT(current_element_valid() == true,
+                         "\tT& array2d::element()()"
+                         << "\n\tYou can only call element() when you are at a valid one."
+                         << "\n\tthis:    " << this
+            );
+
+            return *cur; 
+        }
+
+        bool move_next (
+        ) const
+        {
+            if (cur != 0)
+            {
+                if (cur != last)
+                {
+                    ++cur;
+                    return true;
+                }
+                cur = 0;
+                return false;
+            }
+            else if (at_start_)
+            {
+                cur = data;
+                at_start_ = false;
+                return (data != 0);
+            }
+            else
+            {
+                return false;
+            }
+        }
+
+        size_t size (
+        ) const { return static_cast<size_t>(nc_) * static_cast<size_t>(nr_); }
+
+        long width_step (
+        ) const
+        {
+            return nc_*sizeof(T);
+        }
+
+        iterator begin() 
+        {
+            return data;
+        }
+
+        iterator end()
+        {
+            return data+size();
+        }
+
+        const_iterator begin()  const
+        {
+            return data;
+        }
+
+        const_iterator end() const
+        {
+            return data+size();
+        }
+
+
+    private:
+
+
+        T* data;
+        long nc_;
+        long nr_;
+
+        typename mem_manager::template rebind<T>::other pool;
+        mutable T* cur;
+        T* last;
+        mutable bool at_start_;
+
+    };
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    inline void swap (
+        array2d<T,mem_manager>& a, 
+        array2d<T,mem_manager>& b 
+    ) { a.swap(b); }   
+
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void serialize (
+        const array2d<T,mem_manager>& item, 
+        std::ostream& out 
+    )   
+    {
+        try
+        {
+            // The reason the serialization is a little funny is because we are trying to
+            // maintain backwards compatibility with an older serialization format used by
+            // dlib while also encoding things in a way that lets the array2d and matrix
+            // objects have compatible serialization formats.
+            serialize(-item.nr(),out);
+            serialize(-item.nc(),out);
+
+            item.reset();
+            while (item.move_next())
+                serialize(item.element(),out);
+            item.reset();
+        }
+        catch (serialization_error& e)
+        { 
+            throw serialization_error(e.info + "\n   while serializing object of type array2d"); 
+        }
+    }
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void deserialize (
+        array2d<T,mem_manager>& item, 
+        std::istream& in
+    )   
+    {
+        try
+        {
+            long nr, nc;
+            deserialize(nr,in);
+            deserialize(nc,in);
+
+            // this is the newer serialization format
+            if (nr < 0 || nc < 0)
+            {
+                nr *= -1;
+                nc *= -1;
+            }
+            else
+            {
+                std::swap(nr,nc);
+            }
+
+            item.set_size(nr,nc);
+
+            while (item.move_next())
+                deserialize(item.element(),in); 
+            item.reset();
+        }
+        catch (serialization_error& e)
+        { 
+            item.clear();
+            throw serialization_error(e.info + "\n   while deserializing object of type array2d"); 
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+    // member function definitions
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void array2d<T,mem_manager>::
+    set_size (
+        long rows,
+        long cols
+    )
+    {
+        // make sure requires clause is not broken
+        DLIB_ASSERT((cols >= 0 && rows >= 0) ,
+               "\tvoid array2d::set_size(long rows, long cols)"
+               << "\n\tThe array2d can't have negative rows or columns."
+               << "\n\tthis: " << this
+               << "\n\tcols: " << cols 
+               << "\n\trows: " << rows 
+        );
+
+        // set the enumerator back at the start
+        at_start_ = true;
+        cur = 0;
+
+        // don't do anything if we are already the right size.
+        if (nc_ == cols && nr_ == rows)
+        {
+            return;
+        }
+
+        nc_ = cols;
+        nr_ = rows;
+
+        // free any existing memory
+        if (data != 0)
+        {
+            pool.deallocate_array(data);
+            data = 0;
+        }
+
+        // now setup this object to have the new size
+        try
+        {
+            if (nr_ > 0)
+            {
+                data = pool.allocate_array(nr_*nc_);
+                last = data + nr_*nc_ - 1;
+            }
+        }
+        catch (...)
+        {
+            if (data)
+                pool.deallocate_array(data);
+
+            data = 0;
+            nc_ = 0;
+            nr_ = 0;
+            last = 0;
+            throw;
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <typename T, typename MM>
+    struct is_array2d <array2d<T,MM> >  
+    {
+        const static bool value = true;
+    };
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_ARRAY2D_KERNEl_1_ 
+

dlib/array2d/array2d_kernel_abstract.h

+// Copyright (C) 2006  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#undef DLIB_ARRAY2D_KERNEl_ABSTRACT_
+#ifdef DLIB_ARRAY2D_KERNEl_ABSTRACT_
+
+#include "../interfaces/enumerable.h"
+#include "../serialize.h"
+#include "../algs.h"
+#include "../geometry/rectangle_abstract.h"
+
+namespace dlib
+{
+
+    template <
+        typename T,
+        typename mem_manager = default_memory_manager 
+        >
+    class array2d : public enumerable<T>
+    {
+
+        /*!
+            REQUIREMENTS ON T
+                T must have a default constructor.
+
+            REQUIREMENTS ON mem_manager
+                must be an implementation of memory_manager/memory_manager_kernel_abstract.h or
+                must be an implementation of memory_manager_global/memory_manager_global_kernel_abstract.h or
+                must be an implementation of memory_manager_stateless/memory_manager_stateless_kernel_abstract.h 
+                mem_manager::type can be set to anything.
+
+            POINTERS AND REFERENCES TO INTERNAL DATA
+                No member functions in this object will invalidate pointers
+                or references to internal data except for the set_size()
+                and clear() member functions.
+
+            INITIAL VALUE
+                nr() == 0
+                nc() == 0
+                
+            ENUMERATION ORDER
+                The enumerator will iterate over the elements of the array starting
+                with row 0 and then proceeding to row 1 and so on.  Each row will be
+                fully enumerated before proceeding on to the next row and the elements
+                in a row will be enumerated beginning with the 0th column, then the 1st 
+                column and so on.
+
+            WHAT THIS OBJECT REPRESENTS
+                This object represents a 2-Dimensional array of objects of 
+                type T. 
+
+                Also note that unless specified otherwise, no member functions
+                of this object throw exceptions.
+
+
+                Finally, note that this object stores its data contiguously and in 
+                row major order.  Moreover, there is no padding at the end of each row.
+                This means that its width_step() value is always equal to sizeof(type)*nc().  
+        !*/
+
+
+    public:
+
+        // ----------------------------------------
+
+        typedef T type;
+        typedef mem_manager mem_manager_type;
+        typedef T*          iterator;       
+        typedef const T*    const_iterator; 
+         
+        // ----------------------------------------
+
+        class row 
+        {
+            /*!
+                POINTERS AND REFERENCES TO INTERNAL DATA
+                    No member functions in this object will invalidate pointers
+                    or references to internal data.
+
+                WHAT THIS OBJECT REPRESENTS
+                    This object represents a row of Ts in an array2d object.
+            !*/
+        public:
+            long nc (
+            ) const;
+            /*!
+                ensures
+                    - returns the number of columns in this row
+            !*/
+
+            const T& operator[] (
+                long column
+            ) const;
+            /*!
+                requires
+                    - 0 <= column < nc()
+                ensures
+                    - returns a const reference to the T in the given column 
+            !*/
+
+            T& operator[] (
+                long column
+            );
+            /*!
+                requires
+                    - 0 <= column < nc()
+                ensures
+                    - returns a non-const reference to the T in the given column 
+            !*/
+
+        private:
+            // restricted functions
+            row();
+            row& operator=(row&);
+        };
+
+        // ----------------------------------------
+
+        array2d (
+        );
+        /*!
+            ensures 
+                - #*this is properly initialized
+            throws
+                - std::bad_alloc 
+        !*/
+
+        array2d(const array2d&) = delete;        // copy constructor
+        array2d& operator=(const array2d&) = delete;    // assignment operator
+
+        array2d(
+            array2d&& item
+        );
+        /*!
+            ensures
+                - Moves the state of item into *this.
+                - #item is in a valid but unspecified state.
+        !*/
+
+        array2d (
+            long rows,
+            long cols 
+        );
+        /*!
+            requires
+                - rows >= 0 && cols >= 0
+            ensures
+                - #nc() == cols
+                - #nr() == rows
+                - #at_start() == true
+                - all elements in this array have initial values for their type
+            throws
+                - std::bad_alloc 
+        !*/
+
+        virtual ~array2d (
+        ); 
+        /*!
+            ensures
+                - all resources associated with *this has been released
+        !*/
+        
+        void clear (
+        );
+        /*!
+            ensures
+                - #*this has an initial value for its type
+        !*/
+
+        long nc (
+        ) const;
+        /*!
+            ensures
+                - returns the number of elements there are in a row.  i.e. returns
+                  the number of columns in *this
+        !*/
+
+        long nr (
+        ) const;
+        /*!
+            ensures
+                - returns the number of rows in *this
+        !*/
+
+        void set_size (
+            long rows,
+            long cols
+        );
+        /*!
+            requires
+                - rows >= 0 && cols >= 0
+            ensures
+                - #nc() == cols
+                - #nr() == rows
+                - #at_start() == true
+                - if (the call to set_size() doesn't change the dimensions of this array) then
+                    - all elements in this array retain their values from before this function was called
+                - else
+                    - all elements in this array have initial values for their type
+            throws
+                - std::bad_alloc 
+                    If this exception is thrown then #*this will have an initial
+                    value for its type.
+        !*/
+
+        row operator[] (
+            long row_index
+        );
+        /*!
+            requires
+                - 0 <= row_index < nr()
+            ensures
+                - returns a non-const row of nc() elements that represents the 
+                  given row_index'th row in *this.
+        !*/
+
+        const row operator[] (
+            long row_index
+        ) const;
+        /*!
+            requires
+                - 0 <= row_index < nr()
+            ensures
+                - returns a const row of nc() elements that represents the 
+                  given row_index'th row in *this.
+        !*/
+
+        void swap (
+            array2d& item
+        );
+        /*!
+            ensures
+                - swaps *this and item
+        !*/ 
+
+        array2d& operator= (
+            array2d&& rhs
+        );
+        /*!
+            ensures
+                - Moves the state of item into *this.
+                - #item is in a valid but unspecified state.
+                - returns #*this
+        !*/
+
+        long width_step (
+        ) const;
+        /*!
+            ensures
+                - returns the size of one row of the image, in bytes.  
+                  More precisely, return a number N such that:
+                  (char*)&item[0][0] + N == (char*)&item[1][0].
+                - for dlib::array2d objects, the returned value
+                  is always equal to sizeof(type)*nc().  However,
+                  other objects which implement dlib::array2d style
+                  interfaces might have padding at the ends of their
+                  rows and therefore might return larger numbers.
+                  An example of such an object is the dlib::cv_image.
+        !*/
+
+        iterator begin(
+        );
+        /*!
+            ensures
+                - returns a random access iterator pointing to the first element in this
+                  object.
+                - The iterator will iterate over the elements of the object in row major
+                  order.
+        !*/
+
+        iterator end(
+        );
+        /*!
+            ensures
+                - returns a random access iterator pointing to one past the end of the last
+                  element in this object.
+        !*/
+
+        const_iterator begin(
+        ) const;
+        /*!
+            ensures
+                - returns a random access iterator pointing to the first element in this
+                  object.
+                - The iterator will iterate over the elements of the object in row major
+                  order.
+        !*/
+
+        const_iterator end(
+        ) const;
+        /*!
+            ensures
+                - returns a random access iterator pointing to one past the end of the last
+                  element in this object.
+        !*/
+
+    };
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    inline void swap (
+        array2d<T,mem_manager>& a, 
+        array2d<T,mem_manager>& b 
+    ) { a.swap(b); }   
+    /*!
+        provides a global swap function
+    !*/
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void serialize (
+        const array2d<T,mem_manager>& item, 
+        std::ostream& out 
+    );   
+    /*!
+        Provides serialization support.  Note that the serialization formats used by the
+        dlib::matrix and dlib::array2d objects are compatible.  That means you can load the
+        serialized data from one into another and it will work properly.
+    !*/
+
+    template <
+        typename T,
+        typename mem_manager
+        >
+    void deserialize (
+        array2d<T,mem_manager>& item, 
+        std::istream& in
+    );   
+    /*!
+        provides deserialization support 
+    !*/
+
+}
+
+#endif // DLIB_ARRAY2D_KERNEl_ABSTRACT_ 
+

dlib/array2d/serialize_pixel_overloads.h

+// Copyright (C) 2006  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_ARRAY2D_SERIALIZE_PIXEL_OvERLOADS_Hh_
+#define DLIB_ARRAY2D_SERIALIZE_PIXEL_OvERLOADS_Hh_
+
+#include "array2d_kernel.h"
+#include "../pixel.h"
+
+namespace dlib
+{
+
+// ----------------------------------------------------------------------------------------
+
+    /*
+        This file contains overloads of the serialize functions for array2d object
+        for the case where they contain simple 8bit POD pixel types.  In these
+        cases we can perform a much faster serialization by writing data in chunks
+        instead of one pixel at a time (this avoids a lot of function call overhead
+        inside the iostreams).
+    */
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename mem_manager
+        >
+    void serialize (
+        const array2d<rgb_pixel,mem_manager>& item, 
+        std::ostream& out 
+    )   
+    {
+        try
+        {
+            // The reason the serialization is a little funny is because we are trying to
+            // maintain backwards compatibility with an older serialization format used by
+            // dlib while also encoding things in a way that lets the array2d and matrix
+            // objects have compatible serialization formats.
+            serialize(-item.nr(),out);
+            serialize(-item.nc(),out);
+
+            COMPILE_TIME_ASSERT(sizeof(rgb_pixel) == 3);
+            
+            if (item.size() != 0)
+                out.write((char*)&item[0][0], sizeof(rgb_pixel)*item.size());
+        }
+        catch (serialization_error& e)
+        { 
+            throw serialization_error(e.info + "\n   while serializing object of type array2d"); 
+        }
+    }
+
+    template <
+        typename mem_manager
+        >
+    void deserialize (
+        array2d<rgb_pixel,mem_manager>& item, 
+        std::istream& in
+    )   
+    {
+        try
+        {
+            COMPILE_TIME_ASSERT(sizeof(rgb_pixel) == 3);
+
+            long nr, nc;
+            deserialize(nr,in);
+            deserialize(nc,in);
+
+            // this is the newer serialization format
+            if (nr < 0 || nc < 0)
+            {
+                nr *= -1;
+                nc *= -1;
+            }
+            else
+            {
+                std::swap(nr,nc);
+            }
+
+            item.set_size(nr,nc);
+
+            if (item.size() != 0)
+                in.read((char*)&item[0][0], sizeof(rgb_pixel)*item.size());
+        }
+        catch (serialization_error& e)
+        { 
+            item.clear();
+            throw serialization_error(e.info + "\n   while deserializing object of type array2d"); 
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename mem_manager
+        >
+    void serialize (
+        const array2d<bgr_pixel,mem_manager>& item, 
+        std::ostream& out 
+    )   
+    {
+        try
+        {
+            // The reason the serialization is a little funny is because we are trying to
+            // maintain backwards compatibility with an older serialization format used by
+            // dlib while also encoding things in a way that lets the array2d and matrix
+            // objects have compatible serialization formats.
+            serialize(-item.nr(),out);
+            serialize(-item.nc(),out);
+
+            COMPILE_TIME_ASSERT(sizeof(bgr_pixel) == 3);
+
+            if (item.size() != 0)
+                out.write((char*)&item[0][0], sizeof(bgr_pixel)*item.size());
+        }
+        catch (serialization_error& e)
+        { 
+            throw serialization_error(e.info + "\n   while serializing object of type array2d"); 
+        }
+    }
+
+    template <
+        typename mem_manager
+        >
+    void deserialize (
+        array2d<bgr_pixel,mem_manager>& item, 
+        std::istream& in
+    )   
+    {
+        try
+        {
+            COMPILE_TIME_ASSERT(sizeof(bgr_pixel) == 3);
+
+            long nr, nc;
+            deserialize(nr,in);
+            deserialize(nc,in);
+
+            // this is the newer serialization format
+            if (nr < 0 || nc < 0)
+            {
+                nr *= -1;
+                nc *= -1;
+            }
+            else
+            {
+                std::swap(nr,nc);
+            }
+
+
+            item.set_size(nr,nc);
+
+            if (item.size() != 0)
+                in.read((char*)&item[0][0], sizeof(bgr_pixel)*item.size());
+        }
+        catch (serialization_error& e)
+        { 
+            item.clear();
+            throw serialization_error(e.info + "\n   while deserializing object of type array2d"); 
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename mem_manager
+        >
+    void serialize (
+        const array2d<hsi_pixel,mem_manager>& item, 
+        std::ostream& out 
+    )   
+    {
+        try
+        {
+            // The reason the serialization is a little funny is because we are trying to
+            // maintain backwards compatibility with an older serialization format used by
+            // dlib while also encoding things in a way that lets the array2d and matrix
+            // objects have compatible serialization formats.
+            serialize(-item.nr(),out);
+            serialize(-item.nc(),out);
+
+            COMPILE_TIME_ASSERT(sizeof(hsi_pixel) == 3);
+
+            if (item.size() != 0)
+                out.write((char*)&item[0][0], sizeof(hsi_pixel)*item.size());
+        }
+        catch (serialization_error& e)
+        { 
+            throw serialization_error(e.info + "\n   while serializing object of type array2d"); 
+        }
+    }
+
+    template <
+        typename mem_manager
+        >
+    void deserialize (
+        array2d<hsi_pixel,mem_manager>& item, 
+        std::istream& in
+    )   
+    {
+        try
+        {
+            COMPILE_TIME_ASSERT(sizeof(hsi_pixel) == 3);
+
+            long nr, nc;
+            deserialize(nr,in);
+            deserialize(nc,in);
+
+            // this is the newer serialization format
+            if (nr < 0 || nc < 0)
+            {
+                nr *= -1;
+                nc *= -1;
+            }
+            else
+            {
+                std::swap(nr,nc);
+            }
+
+
+            item.set_size(nr,nc);
+
+            if (item.size() != 0)
+                in.read((char*)&item[0][0], sizeof(hsi_pixel)*item.size());
+        }
+        catch (serialization_error& e)
+        { 
+            item.clear();
+            throw serialization_error(e.info + "\n   while deserializing object of type array2d"); 
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename mem_manager
+        >
+    void serialize (
+        const array2d<rgb_alpha_pixel,mem_manager>& item, 
+        std::ostream& out 
+    )   
+    {
+        try
+        {
+            // The reason the serialization is a little funny is because we are trying to
+            // maintain backwards compatibility with an older serialization format used by
+            // dlib while also encoding things in a way that lets the array2d and matrix
+            // objects have compatible serialization formats.
+            serialize(-item.nr(),out);
+            serialize(-item.nc(),out);
+
+            COMPILE_TIME_ASSERT(sizeof(rgb_alpha_pixel) == 4);
+
+            if (item.size() != 0)
+                out.write((char*)&item[0][0], sizeof(rgb_alpha_pixel)*item.size());
+        }
+        catch (serialization_error& e)
+        { 
+            throw serialization_error(e.info + "\n   while serializing object of type array2d"); 
+        }
+    }
+
+    template <
+        typename mem_manager
+        >
+    void deserialize (
+        array2d<rgb_alpha_pixel,mem_manager>& item, 
+        std::istream& in
+    )   
+    {
+        try
+        {
+            COMPILE_TIME_ASSERT(sizeof(rgb_alpha_pixel) == 4);
+
+            long nr, nc;
+            deserialize(nr,in);
+            deserialize(nc,in);
+
+            // this is the newer serialization format
+            if (nr < 0 || nc < 0)
+            {
+                nr *= -1;
+                nc *= -1;
+            }
+            else
+            {
+                std::swap(nr,nc);
+            }
+
+
+            item.set_size(nr,nc);
+
+            if (item.size() != 0)
+                in.read((char*)&item[0][0], sizeof(rgb_alpha_pixel)*item.size());
+        }
+        catch (serialization_error& e)
+        { 
+            item.clear();
+            throw serialization_error(e.info + "\n   while deserializing object of type array2d"); 
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename mem_manager
+        >
+    void serialize (
+        const array2d<unsigned char,mem_manager>& item, 
+        std::ostream& out 
+    )   
+    {
+        try
+        {
+            // The reason the serialization is a little funny is because we are trying to
+            // maintain backwards compatibility with an older serialization format used by
+            // dlib while also encoding things in a way that lets the array2d and matrix
+            // objects have compatible serialization formats.
+            serialize(-item.nr(),out);
+            serialize(-item.nc(),out);
+
+            if (item.size() != 0)
+                out.write((char*)&item[0][0], sizeof(unsigned char)*item.size());
+        }
+        catch (serialization_error& e)
+        { 
+            throw serialization_error(e.info + "\n   while serializing object of type array2d"); 
+        }
+    }
+
+    template <
+        typename mem_manager
+        >
+    void deserialize (
+        array2d<unsigned char,mem_manager>& item, 
+        std::istream& in
+    )   
+    {
+        try
+        {
+            long nr, nc;
+            deserialize(nr,in);
+            deserialize(nc,in);
+            // this is the newer serialization format
+            if (nr < 0 || nc < 0)
+            {
+                nr *= -1;
+                nc *= -1;
+            }
+            else
+            {
+                std::swap(nr,nc);
+            }
+
+
+            item.set_size(nr,nc);
+
+            if (item.size() != 0)
+                in.read((char*)&item[0][0], sizeof(unsigned char)*item.size());
+        }
+        catch (serialization_error& e)
+        { 
+            item.clear();
+            throw serialization_error(e.info + "\n   while deserializing object of type array2d"); 
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_ARRAY2D_SERIALIZE_PIXEL_OvERLOADS_Hh_
+

dlib/assert.h

+// Copyright (C) 2003  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_ASSERt_
+#define DLIB_ASSERt_
+
+#include "config.h"
+#include <sstream>
+#include <iosfwd>
+#include "error.h"
+
+// -----------------------------
+
+// Use some stuff from boost here
+//  (C) Copyright John Maddock 2001 - 2003.
+//  (C) Copyright Darin Adler 2001.
+//  (C) Copyright Peter Dimov 2001.
+//  (C) Copyright Bill Kempf 2002.
+//  (C) Copyright Jens Maurer 2002.
+//  (C) Copyright David Abrahams 2002 - 2003.
+//  (C) Copyright Gennaro Prota 2003.
+//  (C) Copyright Eric Friedman 2003.
+// License: Boost Software License   See LICENSE.txt for the full license.
+// 
+#ifndef DLIB_BOOST_JOIN
+#define DLIB_BOOST_JOIN( X, Y ) DLIB_BOOST_DO_JOIN( X, Y )
+#define DLIB_BOOST_DO_JOIN( X, Y ) DLIB_BOOST_DO_JOIN2(X,Y)
+#define DLIB_BOOST_DO_JOIN2( X, Y ) X##Y
+#endif
+
+// figure out if the compiler has rvalue references. 
+#if defined(__clang__) 
+#   if __has_feature(cxx_rvalue_references)
+#       define DLIB_HAS_RVALUE_REFERENCES
+#   endif
+#   if __has_feature(cxx_generalized_initializers)
+#       define DLIB_HAS_INITIALIZER_LISTS
+#   endif
+#elif defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 2)) && defined(__GXX_EXPERIMENTAL_CXX0X__) 
+#   define DLIB_HAS_RVALUE_REFERENCES
+#   define DLIB_HAS_INITIALIZER_LISTS
+#elif defined(_MSC_VER) && _MSC_VER >= 1800
+#   define DLIB_HAS_INITIALIZER_LISTS
+#   define DLIB_HAS_RVALUE_REFERENCES
+#elif defined(_MSC_VER) && _MSC_VER >= 1600
+#   define DLIB_HAS_RVALUE_REFERENCES
+#elif defined(__INTEL_COMPILER) && defined(BOOST_INTEL_STDCXX0X)
+#   define DLIB_HAS_RVALUE_REFERENCES
+#   define DLIB_HAS_INITIALIZER_LISTS
+#endif
+
+#if defined(__APPLE__) && defined(__GNUC_LIBSTD__) && ((__GNUC_LIBSTD__-0) * 100 + __GNUC_LIBSTD_MINOR__-0 <= 402)
+ // Apple has not updated libstdc++ in some time and anything under 4.02 does not have <initializer_list> for sure.
+#   undef DLIB_HAS_INITIALIZER_LISTS
+#endif
+
+// figure out if the compiler has static_assert. 
+#if defined(__clang__) 
+#   if __has_feature(cxx_static_assert)
+#       define DLIB_HAS_STATIC_ASSERT
+#   endif
+#elif defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 2)) && defined(__GXX_EXPERIMENTAL_CXX0X__) 
+#   define DLIB_HAS_STATIC_ASSERT
+#elif defined(_MSC_VER) && _MSC_VER >= 1600
+#   define DLIB_HAS_STATIC_ASSERT
+#elif defined(__INTEL_COMPILER) && defined(BOOST_INTEL_STDCXX0X)
+#   define DLIB_HAS_STATIC_ASSERT
+#endif
+
+
+// -----------------------------
+
+namespace dlib
+{
+    template <bool value> struct compile_time_assert;
+    template <> struct compile_time_assert<true> { enum {value=1};  };
+
+    template <typename T, typename U> struct assert_are_same_type;
+    template <typename T> struct assert_are_same_type<T,T> {enum{value=1};};
+    template <typename T, typename U> struct assert_are_not_same_type {enum{value=1}; };
+    template <typename T> struct assert_are_not_same_type<T,T> {};
+
+    template <typename T, typename U> struct assert_types_match {enum{value=0};};
+    template <typename T> struct assert_types_match<T,T> {enum{value=1};};
+}
+
+
+// gcc 4.8 will warn about unused typedefs.  But we use typedefs in some of the compile
+// time assert macros so we need to make it not complain about them "not being used".
+#ifdef __GNUC__
+#define DLIB_NO_WARN_UNUSED __attribute__ ((unused))
+#else
+#define DLIB_NO_WARN_UNUSED 
+#endif
+
+// Use the newer static_assert if it's available since it produces much more readable error
+// messages.
+#ifdef DLIB_HAS_STATIC_ASSERT
+    #define COMPILE_TIME_ASSERT(expression) static_assert(expression, "Failed assertion")
+    #define ASSERT_ARE_SAME_TYPE(type1, type2) static_assert(::dlib::assert_types_match<type1,type2>::value, "These types should be the same but aren't.")
+    #define ASSERT_ARE_NOT_SAME_TYPE(type1, type2) static_assert(!::dlib::assert_types_match<type1,type2>::value, "These types should NOT be the same.")
+#else
+    #define COMPILE_TIME_ASSERT(expression) \
+        DLIB_NO_WARN_UNUSED typedef char DLIB_BOOST_JOIN(DLIB_CTA, __LINE__)[::dlib::compile_time_assert<(bool)(expression)>::value] 
+
+    #define ASSERT_ARE_SAME_TYPE(type1, type2) \
+        DLIB_NO_WARN_UNUSED typedef char DLIB_BOOST_JOIN(DLIB_AAST, __LINE__)[::dlib::assert_are_same_type<type1,type2>::value] 
+
+    #define ASSERT_ARE_NOT_SAME_TYPE(type1, type2) \
+        DLIB_NO_WARN_UNUSED typedef char DLIB_BOOST_JOIN(DLIB_AANST, __LINE__)[::dlib::assert_are_not_same_type<type1,type2>::value] 
+#endif
+
+// -----------------------------
+
+#if defined DLIB_DISABLE_ASSERTS
+    // if DLIB_DISABLE_ASSERTS is on then never enable DLIB_ASSERT no matter what.
+    #undef ENABLE_ASSERTS
+#endif
+
+#if !defined(DLIB_DISABLE_ASSERTS) && ( defined DEBUG || defined _DEBUG)
+    // make sure ENABLE_ASSERTS is defined if we are indeed using them.
+    #ifndef ENABLE_ASSERTS
+        #define ENABLE_ASSERTS
+    #endif
+#endif
+
+// -----------------------------
+
+#ifdef __GNUC__
+// There is a bug in version 4.4.5 of GCC on Ubuntu which causes GCC to segfault
+// when __PRETTY_FUNCTION__ is used within certain templated functions.  So just
+// don't use it with this version of GCC.
+#  if !(__GNUC__ == 4 && __GNUC_MINOR__ == 4 && __GNUC_PATCHLEVEL__ == 5)
+#    define DLIB_FUNCTION_NAME __PRETTY_FUNCTION__
+#  else
+#    define DLIB_FUNCTION_NAME "unknown function" 
+#  endif
+#elif defined(_MSC_VER)
+#define DLIB_FUNCTION_NAME __FUNCSIG__
+#else
+#define DLIB_FUNCTION_NAME "unknown function" 
+#endif
+
+#define DLIBM_CASSERT(_exp,_message)                                              \
+    {if ( !(_exp) )                                                         \
+    {                                                                       \
+        dlib_assert_breakpoint();                                           \
+        std::ostringstream dlib_o_out;                                       \
+        dlib_o_out << "\n\nError detected at line " << __LINE__ << ".\n";    \
+        dlib_o_out << "Error detected in file " << __FILE__ << ".\n";      \
+        dlib_o_out << "Error detected in function " << DLIB_FUNCTION_NAME << ".\n\n";      \
+        dlib_o_out << "Failing expression was " << #_exp << ".\n";           \
+        dlib_o_out << std::boolalpha << _message << "\n";                    \
+        throw dlib::fatal_error(dlib::EBROKEN_ASSERT,dlib_o_out.str());      \
+    }}                                                                      
+
+// This macro is not needed if you have a real C++ compiler.  It's here to work around bugs in Visual Studio's preprocessor.  
+#define DLIB_WORKAROUND_VISUAL_STUDIO_BUGS(x) x
+// Make it so the 2nd argument of DLIB_CASSERT is optional.  That is, you can call it like
+// DLIB_CASSERT(exp) or DLIB_CASSERT(exp,message).
+#define DLIBM_CASSERT_1_ARGS(exp)              DLIBM_CASSERT(exp,"")
+#define DLIBM_CASSERT_2_ARGS(exp,message)      DLIBM_CASSERT(exp,message)
+#define DLIBM_GET_3TH_ARG(arg1, arg2, arg3, ...) arg3
+#define DLIBM_CASSERT_CHOOSER(...) DLIB_WORKAROUND_VISUAL_STUDIO_BUGS(DLIBM_GET_3TH_ARG(__VA_ARGS__,  DLIBM_CASSERT_2_ARGS, DLIBM_CASSERT_1_ARGS, DLIB_CASSERT_NEVER_USED))
+#define DLIB_CASSERT(...) DLIB_WORKAROUND_VISUAL_STUDIO_BUGS(DLIBM_CASSERT_CHOOSER(__VA_ARGS__)(__VA_ARGS__))
+
+
+#ifdef ENABLE_ASSERTS 
+    #define DLIB_ASSERT(...) DLIB_CASSERT(__VA_ARGS__)
+    #define DLIB_IF_ASSERT(exp) exp
+#else
+    #define DLIB_ASSERT(...) {}
+    #define DLIB_IF_ASSERT(exp) 
+#endif
+
+// ----------------------------------------------------------------------------------------
+
+    /*!A DLIB_ASSERT_HAS_STANDARD_LAYOUT 
+    
+        This macro is meant to cause a compiler error if a type doesn't have a simple
+        memory layout (like a C struct). In particular, types with simple layouts are
+        ones which can be copied via memcpy().
+        
+        
+        This was called a POD type in C++03 and in C++0x we are looking to check if 
+        it is a "standard layout type".  Once we can use C++0x we can change this macro 
+        to something that uses the std::is_standard_layout type_traits class.  
+        See: http://www2.research.att.com/~bs/C++0xFAQ.html#PODs
+    !*/
+    // Use the fact that in C++03 you can't put non-PODs into a union.
+#define DLIB_ASSERT_HAS_STANDARD_LAYOUT(type)   \
+    union  DLIB_BOOST_JOIN(DAHSL_,__LINE__) { type TYPE_NOT_STANDARD_LAYOUT; };  \
+    DLIB_NO_WARN_UNUSED typedef char DLIB_BOOST_JOIN(DAHSL2_,__LINE__)[sizeof(DLIB_BOOST_JOIN(DAHSL_,__LINE__))]; 
+
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+
+// breakpoints
+extern "C"
+{
+    inline void dlib_assert_breakpoint(
+    ) {}
+    /*!
+        ensures
+            - this function does nothing 
+              It exists just so you can put breakpoints on it in a debugging tool.
+              It is called only when an DLIB_ASSERT or DLIB_CASSERT fails and is about to
+              throw an exception.
+    !*/
+}
+
+// -----------------------------
+
+#include "stack_trace.h"
+
+#endif // DLIB_ASSERt_
+

dlib/base64.h

+// Copyright (C) 2006  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_BASe64_
+#define DLIB_BASe64_
+
+#include "base64/base64_kernel_1.h"
+
+#endif // DLIB_BASe64_
+

dlib/base64/base64_kernel_1.cpp

+// Copyright (C) 2006  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_BASE64_KERNEL_1_CPp_
+#define DLIB_BASE64_KERNEL_1_CPp_
+
+#include "base64_kernel_1.h"
+#include <iostream>
+#include <sstream>
+#include <climits>
+
+namespace dlib
+{
+
+// ----------------------------------------------------------------------------------------
+
+    base64::line_ending_type base64::
+    line_ending (
+    ) const
+    {
+        return eol_style;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void base64::
+    set_line_ending (
+        line_ending_type eol_style_
+    )
+    {
+        eol_style = eol_style_;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    base64::
+    base64 (
+    ) : 
+        encode_table(0),
+        decode_table(0),
+        bad_value(100),
+        eol_style(LF)
+    {
+        try
+        {
+            encode_table = new char[64];
+            decode_table = new unsigned char[UCHAR_MAX];
+        }
+        catch (...)
+        {
+            if (encode_table) delete [] encode_table;
+            if (decode_table) delete [] decode_table;
+            throw;
+        }
+
+        // now set up the tables with the right stuff
+        encode_table[0] = 'A';
+        encode_table[17] = 'R';
+        encode_table[34] = 'i';
+        encode_table[51] = 'z';
+
+        encode_table[1] = 'B';
+        encode_table[18] = 'S';
+        encode_table[35] = 'j';
+        encode_table[52] = '0';
+
+        encode_table[2] = 'C';
+        encode_table[19] = 'T';
+        encode_table[36] = 'k';
+        encode_table[53] = '1';
+
+        encode_table[3] = 'D';
+        encode_table[20] = 'U';
+        encode_table[37] = 'l';
+        encode_table[54] = '2';
+
+        encode_table[4] = 'E';
+        encode_table[21] = 'V';
+        encode_table[38] = 'm';
+        encode_table[55] = '3';
+
+        encode_table[5] = 'F';
+        encode_table[22] = 'W';
+        encode_table[39] = 'n';
+        encode_table[56] = '4';
+
+        encode_table[6] = 'G';
+        encode_table[23] = 'X';
+        encode_table[40] = 'o';
+        encode_table[57] = '5';
+
+        encode_table[7] = 'H';
+        encode_table[24] = 'Y';
+        encode_table[41] = 'p';
+        encode_table[58] = '6';
+
+        encode_table[8] = 'I';
+        encode_table[25] = 'Z';
+        encode_table[42] = 'q';
+        encode_table[59] = '7';
+
+        encode_table[9] = 'J';
+        encode_table[26] = 'a';
+        encode_table[43] = 'r';
+        encode_table[60] = '8';
+
+        encode_table[10] = 'K';
+        encode_table[27] = 'b';
+        encode_table[44] = 's';
+        encode_table[61] = '9';
+
+        encode_table[11] = 'L';
+        encode_table[28] = 'c';
+        encode_table[45] = 't';
+        encode_table[62] = '+';
+
+        encode_table[12] = 'M';
+        encode_table[29] = 'd';
+        encode_table[46] = 'u';
+        encode_table[63] = '/';
+
+        encode_table[13] = 'N';
+        encode_table[30] = 'e';
+        encode_table[47] = 'v';
+
+        encode_table[14] = 'O';
+        encode_table[31] = 'f';
+        encode_table[48] = 'w';
+
+        encode_table[15] = 'P';
+        encode_table[32] = 'g';
+        encode_table[49] = 'x';
+
+        encode_table[16] = 'Q';
+        encode_table[33] = 'h';
+        encode_table[50] = 'y';
+
+
+
+        // we can now fill out the decode_table by using the encode_table
+        for (int i = 0; i < UCHAR_MAX; ++i)
+        {
+            decode_table[i] = bad_value;
+        }
+        for (unsigned char i = 0; i < 64; ++i)
+        {
+            decode_table[(unsigned char)encode_table[i]] = i;
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    base64::
+    ~base64 (
+    )
+    {
+        delete [] encode_table;
+        delete [] decode_table;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void base64::
+    encode (
+        std::istream& in_,
+        std::ostream& out_
+    ) const
+    {
+        using namespace std;
+        streambuf& in = *in_.rdbuf();
+        streambuf& out = *out_.rdbuf();
+
+        unsigned char inbuf[3];
+        unsigned char outbuf[4];
+        streamsize status = in.sgetn(reinterpret_cast<char*>(&inbuf),3);
+
+        unsigned char c1, c2, c3, c4, c5, c6;
+
+        int counter = 19;
+
+        // while we haven't hit the end of the input stream
+        while (status != 0)
+        {
+            if (counter == 0)
+            {
+                counter = 19;
+                // write a newline
+                char ch;
+                switch (eol_style)
+                {
+                    case CR:
+                        ch = '\r';
+                        if (out.sputn(&ch,1)!=1)
+                            throw std::ios_base::failure("error occurred in the base64 object");
+                        break;
+                    case LF:
+                        ch = '\n';
+                        if (out.sputn(&ch,1)!=1)
+                            throw std::ios_base::failure("error occurred in the base64 object");
+                        break;
+                    case CRLF:
+                        ch = '\r';
+                        if (out.sputn(&ch,1)!=1)
+                            throw std::ios_base::failure("error occurred in the base64 object");
+                        ch = '\n';
+                        if (out.sputn(&ch,1)!=1)
+                            throw std::ios_base::failure("error occurred in the base64 object");
+                        break;
+                    default:
+                        DLIB_CASSERT(false,"this should never happen");
+                }
+            }
+            --counter;
+
+            if (status == 3)
+            {
+                // encode the bytes in inbuf to base64 and write them to the output stream
+                c1 = inbuf[0]&0xfc;
+                c2 = inbuf[0]&0x03;
+                c3 = inbuf[1]&0xf0;
+                c4 = inbuf[1]&0x0f;
+                c5 = inbuf[2]&0xc0;
+                c6 = inbuf[2]&0x3f;
+
+                outbuf[0] = c1>>2;
+                outbuf[1] = (c2<<4)|(c3>>4);
+                outbuf[2] = (c4<<2)|(c5>>6);
+                outbuf[3] = c6;
+
+
+                outbuf[0] = encode_table[outbuf[0]];
+                outbuf[1] = encode_table[outbuf[1]];
+                outbuf[2] = encode_table[outbuf[2]];
+                outbuf[3] = encode_table[outbuf[3]];
+
+                // write the encoded bytes to the output stream
+                if (out.sputn(reinterpret_cast<char*>(&outbuf),4)!=4)
+                {
+                    throw std::ios_base::failure("error occurred in the base64 object");
+                }
+
+                // get 3 more input bytes
+                status = in.sgetn(reinterpret_cast<char*>(&inbuf),3);
+                continue;
+            }
+            else if (status == 2)
+            {
+                // we are at the end of the input stream and need to add some padding
+
+                // encode the bytes in inbuf to base64 and write them to the output stream
+                c1 = inbuf[0]&0xfc;
+                c2 = inbuf[0]&0x03;
+                c3 = inbuf[1]&0xf0;
+                c4 = inbuf[1]&0x0f;
+                c5 = 0;
+
+                outbuf[0] = c1>>2;
+                outbuf[1] = (c2<<4)|(c3>>4);
+                outbuf[2] = (c4<<2)|(c5>>6);
+                outbuf[3] = '=';
+
+                outbuf[0] = encode_table[outbuf[0]];
+                outbuf[1] = encode_table[outbuf[1]];
+                outbuf[2] = encode_table[outbuf[2]];
+
+                // write the encoded bytes to the output stream
+                if (out.sputn(reinterpret_cast<char*>(&outbuf),4)!=4)
+                {
+                    throw std::ios_base::failure("error occurred in the base64 object");
+                }
+
+
+                break;
+            }
+            else // in this case status must be 1 
+            {
+                // we are at the end of the input stream and need to add some padding
+
+                // encode the bytes in inbuf to base64 and write them to the output stream
+                c1 = inbuf[0]&0xfc;
+                c2 = inbuf[0]&0x03;
+                c3 = 0;
+
+                outbuf[0] = c1>>2;
+                outbuf[1] = (c2<<4)|(c3>>4);
+                outbuf[2] = '=';
+                outbuf[3] = '=';
+
+                outbuf[0] = encode_table[outbuf[0]];
+                outbuf[1] = encode_table[outbuf[1]];
+
+
+                // write the encoded bytes to the output stream
+                if (out.sputn(reinterpret_cast<char*>(&outbuf),4)!=4)
+                {
+                    throw std::ios_base::failure("error occurred in the base64 object");
+                }
+
+                break;
+            }
+        } // while (status != 0)
+        
+
+        // make sure the stream buffer flushes to its I/O channel
+        out.pubsync();
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void base64::
+    decode (
+        std::istream& in_,
+        std::ostream& out_
+    ) const
+    {
+        using namespace std;
+        streambuf& in = *in_.rdbuf();
+        streambuf& out = *out_.rdbuf();
+
+        unsigned char inbuf[4];
+        unsigned char outbuf[3];
+        int inbuf_pos = 0;
+        streamsize status = in.sgetn(reinterpret_cast<char*>(inbuf),1);
+
+        // only count this character if it isn't some kind of filler
+        if (status == 1 && decode_table[inbuf[0]] != bad_value )
+            ++inbuf_pos;
+
+        unsigned char c1, c2, c3, c4, c5, c6;
+        streamsize outsize;
+
+        // while we haven't hit the end of the input stream
+        while (status != 0)
+        {
+            // if we have 4 valid characters
+            if (inbuf_pos == 4)
+            {
+                inbuf_pos = 0;
+
+                // this might be the end of the encoded data so we need to figure out if 
+                // there was any padding applied.
+                outsize = 3;
+                if (inbuf[3] == '=')
+                {
+                    if (inbuf[2] == '=')
+                        outsize = 1;
+                    else
+                        outsize = 2;
+                }
+
+                // decode the incoming characters
+                inbuf[0] = decode_table[inbuf[0]];
+                inbuf[1] = decode_table[inbuf[1]];
+                inbuf[2] = decode_table[inbuf[2]];
+                inbuf[3] = decode_table[inbuf[3]];
+
+
+                // now pack these guys into bytes rather than 6 bit chunks
+                c1 = inbuf[0]<<2;
+                c2 = inbuf[1]>>4;
+                c3 = inbuf[1]<<4;
+                c4 = inbuf[2]>>2;
+                c5 = inbuf[2]<<6;
+                c6 = inbuf[3];
+
+                outbuf[0] = c1|c2;
+                outbuf[1] = c3|c4;
+                outbuf[2] = c5|c6;
+
+
+                // write the encoded bytes to the output stream
+                if (out.sputn(reinterpret_cast<char*>(&outbuf),outsize)!=outsize)
+                {
+                    throw std::ios_base::failure("error occurred in the base64 object");
+                }
+            }
+
+            // get more input characters 
+            status = in.sgetn(reinterpret_cast<char*>(inbuf + inbuf_pos),1);
+            // only count this character if it isn't some kind of filler 
+            if ((decode_table[inbuf[inbuf_pos]] != bad_value || inbuf[inbuf_pos] == '=') && 
+                status != 0)
+                ++inbuf_pos;
+        } // while (status != 0)
+        
+        if (inbuf_pos != 0)
+        {
+            ostringstream sout;
+            sout << inbuf_pos << " extra characters were found at the end of the encoded data."
+                << "  This may indicate that the data stream has been truncated.";
+            // this happens if we hit EOF in the middle of decoding a 24bit block.
+            throw decode_error(sout.str());
+        }
+
+        // make sure the stream buffer flushes to its I/O channel
+        out.pubsync();
+    }
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_BASE64_KERNEL_1_CPp_
+

dlib/base64/base64_kernel_1.h

+// Copyright (C) 2006  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_BASE64_KERNEl_1_
+#define DLIB_BASE64_KERNEl_1_
+
+#include "../algs.h"
+#include "base64_kernel_abstract.h"
+#include <iosfwd>
+
+namespace dlib
+{
+
+    class base64 
+    {
+        /*!
+            INITIAL VALUE
+                - bad_value == 100
+                - encode_table == a pointer to an array of 64 chars
+                - where x is a 6 bit value the following is true:
+                    - encode_table[x] == the base64 encoding of x
+                - decode_table == a pointer to an array of UCHAR_MAX chars
+                - where x is any char value:
+                    - if (x is a valid character in the base64 coding scheme) then
+                        - decode_table[x] == the 6 bit value that x encodes
+                    - else
+                        - decode_table[x] == bad_value 
+
+            CONVENTION
+                - The state of this object never changes so just refer to its
+                  initial value.
+                  
+
+        !*/
+
+    public:
+        // this is here for backwards compatibility with older versions of dlib.
+        typedef base64 kernel_1a;
+
+        class decode_error : public dlib::error { public:
+        decode_error( const std::string& e) : error(e) {}};
+
+        base64 (
+        );
+
+        virtual ~base64 (
+        );
+
+        enum line_ending_type
+        {
+            CR,  // i.e. "\r"
+            LF,  // i.e. "\n"
+            CRLF // i.e. "\r\n"
+        };
+
+        line_ending_type line_ending (
+        ) const;
+
+        void set_line_ending (
+            line_ending_type eol_style_
+        );
+
+        void encode (
+            std::istream& in,
+            std::ostream& out
+        ) const;
+
+        void decode (
+            std::istream& in,
+            std::ostream& out
+        ) const;
+
+    private:
+
+        char* encode_table;
+        unsigned char* decode_table;
+        const unsigned char bad_value;
+        line_ending_type eol_style;
+
+        // restricted functions
+        base64(base64&);        // copy constructor
+        base64& operator=(base64&);    // assignment operator
+
+    };   
+   
+}
+
+#ifdef NO_MAKEFILE
+#include "base64_kernel_1.cpp"
+#endif
+
+#endif // DLIB_BASE64_KERNEl_1_
+

dlib/base64/base64_kernel_abstract.h

+// Copyright (C) 2006  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#undef DLIB_BASE64_KERNEl_ABSTRACT_
+#ifdef DLIB_BASE64_KERNEl_ABSTRACT_
+
+#include "../algs.h"
+#include <iosfwd>
+
+namespace dlib
+{
+
+    class base64 
+    {
+        /*!
+            INITIAL VALUE
+                - line_ending() == LF
+
+            WHAT THIS OBJECT REPRESENTS
+                This object consists of the two functions encode and decode.
+                These functions allow you to encode and decode data to and from
+                the Base64 Content-Transfer-Encoding defined in section 6.8 of
+                rfc2045.
+        !*/
+
+    public:
+
+        class decode_error : public dlib::error {};
+
+        base64 (
+        );
+        /*!
+            ensures
+                - #*this is properly initialized
+            throws
+                - std::bad_alloc
+        !*/
+
+        virtual ~base64 (
+        );
+        /*!
+            ensures
+                - all memory associated with *this has been released
+        !*/
+
+        enum line_ending_type
+        {
+            CR,  // i.e. "\r"
+            LF,  // i.e. "\n"
+            CRLF // i.e. "\r\n"
+        };
+
+        line_ending_type line_ending (
+        ) const;
+        /*!
+            ensures
+                - returns the type of end of line bytes the encoder
+                  will use when encoding data to base64 blocks.  Note that
+                  the ostream object you use might apply some sort of transform
+                  to line endings as well.  For example, C++ ofstream objects
+                  usually convert '\n' into whatever a normal newline is for
+                  your platform unless you open a file in binary mode.  But
+                  aside from file streams the ostream objects usually don't
+                  modify the data you pass to them.
+        !*/
+
+        void set_line_ending (
+            line_ending_type eol_style
+        );
+        /*!
+            ensures
+                - #line_ending() == eol_style
+        !*/
+
+        void encode (
+            std::istream& in,
+            std::ostream& out
+        ) const;
+        /*!
+            ensures
+                - reads all data from in (until EOF is reached) and encodes it
+                  and writes it to out
+            throws
+                - std::ios_base::failure
+                    if there was a problem writing to out then this exception will 
+                    be thrown.                      
+                - any other exception
+                    this exception may be thrown if there is any other problem                    
+        !*/
+
+        void decode (
+            std::istream& in,
+            std::ostream& out
+        ) const;
+        /*!
+            ensures
+                - reads data from in (until EOF is reached), decodes it,
+                  and writes it to out. 
+            throws
+                - std::ios_base::failure
+                    if there was a problem writing to out then this exception will 
+                    be thrown.           
+                - decode_error
+                    if an error was detected in the encoded data that prevented
+                    it from being correctly decoded then this exception is 
+                    thrown.  
+                - any other exception
+                    this exception may be thrown if there is any other problem                    
+        !*/
+
+    private:
+
+        // restricted functions
+        base64(base64&);        // copy constructor
+        base64& operator=(base64&);    // assignment operator
+
+    };   
+   
+}
+
+#endif // DLIB_BASE64_KERNEl_ABSTRACT_
+

dlib/bayes_utils.h

+// Copyright (C) 2007  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_BAYES_UTILs_H_
+#define DLIB_BAYES_UTILs_H_ 
+
+#include "bayes_utils/bayes_utils.h"
+
+#endif // DLIB_BAYES_UTILs_H_ 
+
+
+

dlib/bayes_utils/bayes_utils.h

+// Copyright (C) 2007  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_BAYES_UTILs_
+#define DLIB_BAYES_UTILs_
+
+#include "bayes_utils_abstract.h"
+
+#include <algorithm>
+#include <ctime>
+#include <memory>
+#include <vector>
+
+#include "../string.h"
+#include "../map.h"
+#include "../matrix.h"
+#include "../rand.h"
+#include "../array.h"
+#include "../set.h"
+#include "../algs.h"
+#include "../noncopyable.h"
+#include "../graph.h"
+
+namespace dlib
+{
+
+// ----------------------------------------------------------------------------------------
+
+    class assignment 
+    {
+    public:
+
+        assignment()
+        {
+        }
+
+        assignment(
+            const assignment& a
+        )
+        {
+            a.reset();
+            while (a.move_next())
+            {
+                unsigned long idx = a.element().key();
+                unsigned long value = a.element().value();
+                vals.add(idx,value);
+            }
+        }
+
+        assignment& operator = (
+            const assignment& rhs
+        )
+        {
+            if (this == &rhs)
+                return *this;
+
+            assignment(rhs).swap(*this);
+            return *this;
+        }
+
+        void clear()
+        {
+            vals.clear();
+        }
+
+        bool operator < (
+            const assignment& item
+        ) const 
+        {  
+            if (size() < item.size())
+                return true;
+            else if (size() > item.size())
+                return false;
+
+            reset();
+            item.reset();
+            while (move_next())
+            {
+                item.move_next();
+                if (element().key() < item.element().key())
+                    return true;
+                else if (element().key() > item.element().key())
+                    return false;
+                else if (element().value() < item.element().value())
+                    return true;
+                else if (element().value() > item.element().value())
+                    return false;
+            }
+
+            return false;
+        }
+
+        bool has_index (
+            unsigned long idx
+        ) const
+        {
+            return vals.is_in_domain(idx);
+        }
+
+        void add (
+            unsigned long idx,
+            unsigned long value = 0
+        )
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT( has_index(idx) == false ,
+                         "\tvoid assignment::add(idx)"
+                         << "\n\tYou can't add the same index to an assignment object more than once"
+                         << "\n\tidx:  " << idx 
+                         << "\n\tthis: " << this
+            );
+
+            vals.add(idx, value);
+        }
+
+        unsigned long& operator[] (
+            const long idx
+        )
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT( has_index(idx) == true ,
+                         "\tunsigned long assignment::operator[](idx)"
+                         << "\n\tYou can't access an index value if it isn't already in the object"
+                         << "\n\tidx:  " << idx 
+                         << "\n\tthis: " << this
+            );
+
+            return vals[idx];
+        }
+
+        const unsigned long& operator[] (
+            const long idx
+        ) const
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT( has_index(idx) == true ,
+                         "\tunsigned long assignment::operator[](idx)"
+                         << "\n\tYou can't access an index value if it isn't already in the object"
+                         << "\n\tidx:  " << idx 
+                         << "\n\tthis: " << this
+            );
+
+            return vals[idx];
+        }
+
+        void swap (
+            assignment& item
+        )
+        {
+            vals.swap(item.vals);
+        }
+
+        void remove (
+            unsigned long idx
+        )
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT( has_index(idx) == true ,
+                         "\tunsigned long assignment::remove(idx)"
+                         << "\n\tYou can't remove an index value if it isn't already in the object"
+                         << "\n\tidx:  " << idx 
+                         << "\n\tthis: " << this
+            );
+
+            vals.destroy(idx);
+        }
+
+        unsigned long size() const { return vals.size(); }
+
+        void reset() const { vals.reset(); }
+
+        bool move_next() const { return vals.move_next(); }
+
+        map_pair<unsigned long, unsigned long>& element() 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT(current_element_valid() == true,
+                        "\tmap_pair<unsigned long,unsigned long>& assignment::element()"
+                        << "\n\tyou can't access the current element if it doesn't exist"
+                        << "\n\tthis: " << this
+            );
+            return vals.element(); 
+        }
+
+        const map_pair<unsigned long, unsigned long>& element() const 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT(current_element_valid() == true,
+                        "\tconst map_pair<unsigned long,unsigned long>& assignment::element() const"
+                        << "\n\tyou can't access the current element if it doesn't exist"
+                        << "\n\tthis: " << this
+            );
+
+            return vals.element(); 
+        }
+
+        bool at_start() const { return vals.at_start(); }
+
+        bool current_element_valid() const { return vals.current_element_valid(); }
+
+        friend inline void serialize (
+            const assignment& item,
+            std::ostream& out 
+        )   
+        {
+            serialize(item.vals, out);
+        }
+
+        friend inline void deserialize (
+            assignment& item,
+            std::istream& in
+        )
+        {
+            deserialize(item.vals, in);
+        }
+
+    private:
+        mutable dlib::map<unsigned long, unsigned long>::kernel_1b_c vals;
+    };
+
+    inline std::ostream& operator << (
+        std::ostream& out,
+        const assignment& a
+    )
+    {
+        a.reset();
+        out << "(";
+        if (a.move_next())
+            out << a.element().key() << ":" << a.element().value();
+
+        while (a.move_next())
+        {
+            out << ", " << a.element().key() << ":" << a.element().value();
+        }
+
+        out << ")";
+        return out;
+    }
+
+
+    inline void swap (
+        assignment& a,
+        assignment& b
+    )
+    {
+        a.swap(b);
+    }
+
+
+// ------------------------------------------------------------------------
+
+    class joint_probability_table 
+    {
+        /*!
+            INITIAL VALUE
+                - table.size() == 0
+
+            CONVENTION
+                - size() == table.size()
+                - probability(a) == table[a]
+        !*/
+    public:
+
+        joint_probability_table (
+            const joint_probability_table& t
+        )
+        {
+            t.reset();
+            while (t.move_next())
+            {
+                assignment a = t.element().key();
+                double p = t.element().value();
+                set_probability(a,p);
+            }
+        }
+
+        joint_probability_table() {}
+
+        joint_probability_table& operator= (
+            const joint_probability_table& rhs
+        )
+        {
+            if (this == &rhs)
+                return *this;
+            joint_probability_table(rhs).swap(*this);
+            return *this;
+        }
+
+        void set_probability (
+            const assignment& a,
+            double p
+        )
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT(0.0 <= p && p <= 1.0,
+                        "\tvoid& joint_probability_table::set_probability(a,p)"
+                        << "\n\tyou have given an invalid probability value"
+                        << "\n\tp:    " << p 
+                        << "\n\ta:    " << a 
+                        << "\n\tthis: " << this
+            );
+
+            if (table.is_in_domain(a))
+            {
+                table[a] = p;
+            }
+            else
+            {
+                assignment temp(a);
+                table.add(temp,p);
+            }
+        }
+
+        bool has_entry_for (
+            const assignment& a
+        ) const
+        {
+            return table.is_in_domain(a);
+        }
+
+        void add_probability (
+            const assignment& a,
+            double p
+        )
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT(0.0 <= p && p <= 1.0,
+                        "\tvoid& joint_probability_table::add_probability(a,p)"
+                        << "\n\tyou have given an invalid probability value"
+                        << "\n\tp:    " << p 
+                        << "\n\ta:    " << a 
+                        << "\n\tthis: " << this
+            );
+
+            if (table.is_in_domain(a))
+            {
+                table[a] += p;
+                if (table[a] > 1.0)
+                    table[a] = 1.0;
+            }
+            else
+            {
+                assignment temp(a);
+                table.add(temp,p);
+            }
+        }
+
+        double probability (
+            const assignment& a
+        ) const
+        {
+            return table[a];
+        }
+
+        void clear()
+        {
+            table.clear();
+        }
+
+        size_t size () const { return table.size(); }
+        bool move_next() const { return table.move_next(); }
+        void reset() const { table.reset(); }
+        map_pair<assignment,double>& element() 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT(current_element_valid() == true,
+                        "\tmap_pair<assignment,double>& joint_probability_table::element()"
+                        << "\n\tyou can't access the current element if it doesn't exist"
+                        << "\n\tthis: " << this
+            );
+
+            return table.element(); 
+        }
+
+        const map_pair<assignment,double>& element() const 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT(current_element_valid() == true,
+                        "\tconst map_pair<assignment,double>& joint_probability_table::element() const"
+                        << "\n\tyou can't access the current element if it doesn't exist"
+                        << "\n\tthis: " << this
+            );
+
+            return table.element(); 
+        }
+
+        bool at_start() const { return table.at_start(); }
+
+        bool current_element_valid() const { return table.current_element_valid(); }
+
+
+        template <typename T>
+        void marginalize (
+            const T& vars,
+            joint_probability_table& out
+        ) const
+        {
+            out.clear();
+            double p;
+            reset();
+            while (move_next())
+            {
+                assignment a;
+                const assignment& asrc = element().key();
+                p = element().value();
+
+                asrc.reset();
+                while (asrc.move_next())
+                {
+                    if (vars.is_member(asrc.element().key()))
+                        a.add(asrc.element().key(), asrc.element().value());
+                }
+
+                out.add_probability(a,p);
+            }
+        }
+
+        void marginalize (
+            const unsigned long var,
+            joint_probability_table& out
+        ) const
+        {
+            out.clear();
+            double p;
+            reset();
+            while (move_next())
+            {
+                assignment a;
+                const assignment& asrc = element().key();
+                p = element().value();
+
+                asrc.reset();
+                while (asrc.move_next())
+                {
+                    if (var == asrc.element().key())
+                        a.add(asrc.element().key(), asrc.element().value());
+                }
+
+                out.add_probability(a,p);
+            }
+        }
+
+        void normalize (
+        )
+        {
+            double sum = 0;
+
+            reset();
+            while (move_next())
+                sum += element().value();
+
+            reset();
+            while (move_next())
+                element().value() /= sum;
+        }
+
+        void swap (
+            joint_probability_table& item
+        )
+        {
+            table.swap(item.table);
+        }
+
+        friend inline void serialize (
+            const joint_probability_table& item,
+            std::ostream& out 
+        )   
+        {
+            serialize(item.table, out);
+        }
+
+        friend inline void deserialize (
+            joint_probability_table& item,
+            std::istream& in
+        )
+        {
+            deserialize(item.table, in);
+        }
+
+    private:
+
+        dlib::map<assignment, double >::kernel_1b_c table;
+    };
+
+    inline void swap (
+        joint_probability_table& a,
+        joint_probability_table& b
+    ) { a.swap(b); }
+
+// ----------------------------------------------------------------------------------------
+
+    class conditional_probability_table : noncopyable
+    {
+        /*!
+            INITIAL VALUE
+                - table.size() == 0
+
+            CONVENTION
+                - if (table.is_in_domain(ps) && value < num_vals && table[ps](value) >= 0) then
+                    - has_entry_for(value,ps) == true
+                    - probability(value,ps) == table[ps](value)
+                - else
+                    - has_entry_for(value,ps) == false 
+
+                - num_values() == num_vals
+        !*/
+    public:
+
+        conditional_probability_table()
+        {
+            clear();
+        }
+
+        void set_num_values (
+            unsigned long num
+        )
+        {
+            num_vals = num;
+            table.clear();
+        }
+
+        bool has_entry_for (
+            unsigned long value,
+            const assignment& ps
+        ) const
+        {
+            if (table.is_in_domain(ps) && value < num_vals && table[ps](value) >= 0)
+                return true;
+            else
+                return false;
+        }
+
+        unsigned long num_values (
+        ) const { return num_vals; }
+
+        void set_probability (
+            unsigned long value,
+            const assignment& ps,
+            double p
+        )
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT( value < num_values() && 0.0 <= p && p <= 1.0 ,
+                         "\tvoid conditional_probability_table::set_probability()"
+                         << "\n\tinvalid arguments to set_probability"
+                         << "\n\tvalue: " << value 
+                         << "\n\tnum_values(): " << num_values()
+                         << "\n\tp:     " << p 
+                         << "\n\tps:    " << ps 
+                         << "\n\tthis:  " << this
+            );
+
+            if (table.is_in_domain(ps))
+            {
+                table[ps](value) = p;
+            }
+            else
+            {
+                matrix<double,1> dist(num_vals);
+                set_all_elements(dist,-1);
+                dist(value) = p;
+                assignment temp(ps);
+                table.add(temp,dist);
+            }
+        }
+
+        double probability(
+            unsigned long value,
+            const assignment& ps 
+        ) const
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT( value < num_values() && has_entry_for(value,ps) ,
+                         "\tvoid conditional_probability_table::probability()"
+                         << "\n\tinvalid arguments to probability"
+                         << "\n\tvalue:        " << value 
+                         << "\n\tnum_values(): " << num_values() 
+                         << "\n\tps:           " << ps 
+                         << "\n\tthis:         " << this
+            );
+
+            return table[ps](value);
+        }
+
+        void clear()
+        {
+            table.clear();
+            num_vals = 0;
+        }
+
+        void empty_table ()
+        {
+            table.clear();
+        }
+
+        void swap (
+            conditional_probability_table& item 
+        ) 
+        { 
+            exchange(num_vals, item.num_vals);
+            table.swap(item.table);
+        }
+
+        friend inline void serialize (
+            const conditional_probability_table& item,
+            std::ostream& out 
+        )   
+        {
+            serialize(item.table, out);
+            serialize(item.num_vals, out);
+        }
+
+        friend inline void deserialize (
+            conditional_probability_table& item,
+            std::istream& in
+        )
+        {
+            deserialize(item.table, in);
+            deserialize(item.num_vals, in);
+        }
+
+    private:
+        dlib::map<assignment, matrix<double,1> >::kernel_1b_c table;
+        unsigned long num_vals;
+    };
+
+    inline void swap (
+        conditional_probability_table& a,
+        conditional_probability_table& b
+    ) { a.swap(b); }
+
+// ------------------------------------------------------------------------
+
+    class bayes_node : noncopyable
+    {
+    public:
+        bayes_node ()
+        {
+            is_instantiated = false;
+            value_ = 0;
+        }
+
+        unsigned long value (
+        ) const { return value_;}
+
+        void set_value (
+            unsigned long new_value
+        )
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT( new_value < table().num_values(),
+                         "\tvoid bayes_node::set_value(new_value)"
+                         << "\n\tnew_value must be less than the number of possible values for this node"
+                         << "\n\tnew_value:            " << new_value 
+                         << "\n\ttable().num_values(): " << table().num_values() 
+                         << "\n\tthis:                 " << this
+            );
+
+            value_ = new_value;
+        }
+
+        conditional_probability_table& table (
+        ) { return table_; }
+
+        const conditional_probability_table& table (
+        ) const { return table_; }
+
+        bool is_evidence (
+        ) const { return is_instantiated; }
+
+        void set_as_nonevidence (
+        ) { is_instantiated = false; }
+
+        void set_as_evidence (
+        ) { is_instantiated = true; }
+
+        void swap (
+            bayes_node& item 
+        ) 
+        { 
+            exchange(value_, item.value_);
+            exchange(is_instantiated, item.is_instantiated);
+            table_.swap(item.table_);
+        }
+
+        friend inline void serialize (
+            const bayes_node& item,
+            std::ostream& out 
+        )   
+        {
+            serialize(item.value_, out);
+            serialize(item.is_instantiated, out);
+            serialize(item.table_, out);
+        }
+
+        friend inline void deserialize (
+            bayes_node& item,
+            std::istream& in
+        )
+        {
+            deserialize(item.value_, in);
+            deserialize(item.is_instantiated, in);
+            deserialize(item.table_, in);
+        }
+
+    private:
+
+        unsigned long value_; 
+        bool is_instantiated;
+        conditional_probability_table table_;
+    };
+
+    inline void swap (
+        bayes_node& a,
+        bayes_node& b
+    ) { a.swap(b); }
+
+// ------------------------------------------------------------------------
+
+    namespace bayes_node_utils
+    {
+
+        template <typename T>
+        unsigned long node_num_values (
+            const T& bn,
+            unsigned long n
+        )  
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT( n < bn.number_of_nodes(),
+                         "\tvoid bayes_node_utils::node_num_values(bn, n)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                     " << n 
+                         << "\n\tbn.number_of_nodes():  " << bn.number_of_nodes() 
+            );
+
+            return bn.node(n).data.table().num_values(); 
+        }
+
+    // ----------------------------------------------------------------------------------------
+
+        template <typename T>
+        void set_node_value (
+            T& bn,
+            unsigned long n,
+            unsigned long val
+        ) 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT( n < bn.number_of_nodes() && val < node_num_values(bn,n),
+                         "\tvoid bayes_node_utils::set_node_value(bn, n, val)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                     " << n 
+                         << "\n\tval:                   " << val 
+                         << "\n\tbn.number_of_nodes():  " << bn.number_of_nodes() 
+                         << "\n\tnode_num_values(bn,n): " << node_num_values(bn,n) 
+            );
+
+            bn.node(n).data.set_value(val); 
+        }
+
+    // ----------------------------------------------------------------------------------------
+        template <typename T>
+        unsigned long node_value (
+            const T& bn,
+            unsigned long n
+        ) 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT( n < bn.number_of_nodes(),
+                         "\tunsigned long bayes_node_utils::node_value(bn, n)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                     " << n 
+                         << "\n\tbn.number_of_nodes():  " << bn.number_of_nodes() 
+            );
+
+            return bn.node(n).data.value();
+        }
+    // ----------------------------------------------------------------------------------------
+
+        template <typename T>
+        bool node_is_evidence (
+            const T& bn,
+            unsigned long n
+        ) 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT( n < bn.number_of_nodes(),
+                         "\tbool bayes_node_utils::node_is_evidence(bn, n)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                     " << n 
+                         << "\n\tbn.number_of_nodes():  " << bn.number_of_nodes() 
+            );
+
+            return bn.node(n).data.is_evidence();
+        }
+
+    // ----------------------------------------------------------------------------------------
+
+        template <typename T>
+        void set_node_as_evidence (
+            T& bn,
+            unsigned long n
+        ) 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT( n < bn.number_of_nodes(),
+                         "\tvoid bayes_node_utils::set_node_as_evidence(bn, n)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                     " << n 
+                         << "\n\tbn.number_of_nodes():  " << bn.number_of_nodes() 
+            );
+
+            bn.node(n).data.set_as_evidence(); 
+        }
+
+    // ----------------------------------------------------------------------------------------
+        template <typename T>
+        void set_node_as_nonevidence (
+            T& bn,
+            unsigned long n
+        ) 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT( n < bn.number_of_nodes(),
+                         "\tvoid bayes_node_utils::set_node_as_nonevidence(bn, n)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                     " << n 
+                         << "\n\tbn.number_of_nodes():  " << bn.number_of_nodes() 
+            );
+
+            bn.node(n).data.set_as_nonevidence(); 
+        }
+
+    // ----------------------------------------------------------------------------------------
+
+        template <typename T>
+        void set_node_num_values (
+            T& bn,
+            unsigned long n,
+            unsigned long num
+        ) 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT( n < bn.number_of_nodes(),
+                         "\tvoid bayes_node_utils::set_node_num_values(bn, n, num)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                     " << n 
+                         << "\n\tbn.number_of_nodes():  " << bn.number_of_nodes() 
+            );
+
+            bn.node(n).data.table().set_num_values(num); 
+        }
+
+    // ----------------------------------------------------------------------------------------
+
+        template <typename T>
+        double node_probability (
+            const T& bn,
+            unsigned long n,
+            unsigned long value,
+            const assignment& parents 
+        ) 
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT( n < bn.number_of_nodes() && value < node_num_values(bn,n),
+                         "\tdouble bayes_node_utils::node_probability(bn, n, value, parents)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                     " << n 
+                         << "\n\tvalue:                 " << value 
+                         << "\n\tbn.number_of_nodes():  " << bn.number_of_nodes() 
+                         << "\n\tnode_num_values(bn,n): " << node_num_values(bn,n) 
+            );
+
+            DLIB_ASSERT( parents.size() == bn.node(n).number_of_parents(),
+                         "\tdouble bayes_node_utils::node_probability(bn, n, value, parents)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                             " << n 
+                         << "\n\tparents.size():                " << parents.size()
+                         << "\n\tb.node(n).number_of_parents(): " << bn.node(n).number_of_parents()
+            );
+
+#ifdef ENABLE_ASSERTS
+            parents.reset();
+            while (parents.move_next())
+            {
+                const unsigned long x = parents.element().key();
+                DLIB_ASSERT( bn.has_edge(x, n),
+                             "\tdouble bayes_node_utils::node_probability(bn, n, value, parents)"
+                             << "\n\tInvalid arguments to this function"
+                             << "\n\tn: " << n 
+                             << "\n\tx: " << x 
+                );
+                DLIB_ASSERT( parents[x] < node_num_values(bn,x),
+                             "\tdouble bayes_node_utils::node_probability(bn, n, value, parents)"
+                             << "\n\tInvalid arguments to this function"
+                             << "\n\tn:                     " << n 
+                             << "\n\tx:                     " << x 
+                             << "\n\tparents[x]:            " << parents[x] 
+                             << "\n\tnode_num_values(bn,x): " << node_num_values(bn,x) 
+                );
+            }
+#endif
+
+            return bn.node(n).data.table().probability(value, parents);
+        }
+
+    // ----------------------------------------------------------------------------------------
+
+        template <typename T>
+        void set_node_probability (
+            T& bn,
+            unsigned long n,
+            unsigned long value,
+            const assignment& parents,
+            double p
+        )
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT( n < bn.number_of_nodes() && value < node_num_values(bn,n),
+                         "\tvoid bayes_node_utils::set_node_probability(bn, n, value, parents, p)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                     " << n 
+                         << "\n\tp:                     " << p 
+                         << "\n\tvalue:                 " << value 
+                         << "\n\tbn.number_of_nodes():  " << bn.number_of_nodes() 
+                         << "\n\tnode_num_values(bn,n): " << node_num_values(bn,n) 
+            );
+
+            DLIB_ASSERT( parents.size() == bn.node(n).number_of_parents(),
+                         "\tvoid bayes_node_utils::set_node_probability(bn, n, value, parents, p)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                             " << n 
+                         << "\n\tp:                             " << p 
+                         << "\n\tparents.size():                " << parents.size()
+                         << "\n\tbn.node(n).number_of_parents(): " << bn.node(n).number_of_parents()
+            );
+
+            DLIB_ASSERT( 0.0 <= p && p <= 1.0,
+                         "\tvoid bayes_node_utils::set_node_probability(bn, n, value, parents, p)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn: " << n 
+                         << "\n\tp: " << p 
+            );
+
+#ifdef ENABLE_ASSERTS
+            parents.reset();
+            while (parents.move_next())
+            {
+                const unsigned long x = parents.element().key();
+                DLIB_ASSERT( bn.has_edge(x, n),
+                             "\tvoid bayes_node_utils::set_node_probability(bn, n, value, parents, p)"
+                             << "\n\tInvalid arguments to this function"
+                             << "\n\tn: " << n 
+                             << "\n\tx: " << x 
+                );
+                DLIB_ASSERT( parents[x] < node_num_values(bn,x),
+                             "\tvoid bayes_node_utils::set_node_probability(bn, n, value, parents, p)"
+                             << "\n\tInvalid arguments to this function"
+                             << "\n\tn:                     " << n 
+                             << "\n\tx:                     " << x 
+                             << "\n\tparents[x]:            " << parents[x] 
+                             << "\n\tnode_num_values(bn,x): " << node_num_values(bn,x) 
+                );
+            }
+#endif
+
+            bn.node(n).data.table().set_probability(value,parents,p);
+        }
+
+// ----------------------------------------------------------------------------------------
+
+        template <typename T>
+        const assignment node_first_parent_assignment (
+            const T& bn,
+            unsigned long n
+        ) 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT( n < bn.number_of_nodes(),
+                         "\tconst assignment bayes_node_utils::node_first_parent_assignment(bn, n)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                     " << n 
+            );
+
+            assignment a;
+            const unsigned long num_parents = bn.node(n).number_of_parents();
+            for (unsigned long i = 0; i < num_parents; ++i)
+            {
+                a.add(bn.node(n).parent(i).index(), 0);
+            }
+            return a;
+        }
+
+// ----------------------------------------------------------------------------------------
+
+        template <typename T>
+        bool node_next_parent_assignment (
+            const T& bn,
+            unsigned long n,
+            assignment& a
+        ) 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT( n < bn.number_of_nodes(),
+                         "\tbool bayes_node_utils::node_next_parent_assignment(bn, n, a)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                     " << n 
+            );
+
+            DLIB_ASSERT( a.size() == bn.node(n).number_of_parents(),
+                         "\tbool bayes_node_utils::node_next_parent_assignment(bn, n, a)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                             " << n 
+                         << "\n\ta.size():                      " << a.size()
+                         << "\n\tbn.node(n).number_of_parents(): " << bn.node(n).number_of_parents()
+            );
+
+#ifdef ENABLE_ASSERTS
+            a.reset();
+            while (a.move_next())
+            {
+                const unsigned long x = a.element().key();
+                DLIB_ASSERT( bn.has_edge(x, n),
+                             "\tbool bayes_node_utils::node_next_parent_assignment(bn, n, a)"
+                             << "\n\tInvalid arguments to this function"
+                             << "\n\tn: " << n 
+                             << "\n\tx: " << x 
+                );
+                DLIB_ASSERT( a[x] < node_num_values(bn,x),
+                             "\tbool bayes_node_utils::node_next_parent_assignment(bn, n, a)"
+                             << "\n\tInvalid arguments to this function"
+                             << "\n\tn:                     " << n 
+                             << "\n\tx:                     " << x 
+                             << "\n\ta[x]:                  " << a[x] 
+                             << "\n\tnode_num_values(bn,x): " << node_num_values(bn,x) 
+                );
+            }
+#endif
+
+            // basically this loop just adds 1 to the assignment but performs
+            // carries if necessary
+            for (unsigned long p = 0; p < a.size(); ++p)
+            {
+                const unsigned long pindex = bn.node(n).parent(p).index();
+                a[pindex] += 1;
+
+                // if we need to perform a carry
+                if (a[pindex] >= node_num_values(bn,pindex))
+                {
+                    a[pindex] = 0;
+                }
+                else
+                {
+                    // no carry necessary so we are done
+                    return true;
+                }
+            }
+
+            // we got through the entire loop which means a carry propagated all the way out
+            // so there must not be any more valid assignments left
+            return false;
+        }
+
+// ----------------------------------------------------------------------------------------
+
+        template <typename T>
+        bool node_cpt_filled_out (
+            const T& bn,
+            unsigned long n
+        ) 
+        { 
+            // make sure requires clause is not broken
+            DLIB_ASSERT( n < bn.number_of_nodes(),
+                         "\tbool bayes_node_utils::node_cpt_filled_out(bn, n)"
+                         << "\n\tInvalid arguments to this function"
+                         << "\n\tn:                     " << n 
+                         << "\n\tbn.number_of_nodes():  " << bn.number_of_nodes() 
+            );
+
+            const unsigned long num_values = node_num_values(bn,n);
+
+
+            const conditional_probability_table& table = bn.node(n).data.table();
+
+            // now loop over all the possible parent assignments for this node
+            assignment a(node_first_parent_assignment(bn,n));
+            do
+            {
+                double sum = 0;
+                // make sure that this assignment has an entry for all the values this node can take one
+                for (unsigned long value = 0; value < num_values; ++value)
+                {
+                    if (table.has_entry_for(value,a) == false)
+                        return false;
+                    else
+                        sum += table.probability(value,a);
+                }
+
+                // check if the sum of probabilities equals 1 as it should
+                if (std::abs(sum-1.0) > 1e-5)
+                    return false;
+            } while (node_next_parent_assignment(bn,n,a));
+
+            return true;
+        }
+
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    class bayesian_network_gibbs_sampler : noncopyable
+    {
+    public:
+
+        bayesian_network_gibbs_sampler ()
+        {
+            rnd.set_seed(cast_to_string(std::time(0)));
+        }
+
+
+        template <
+            typename T
+            >
+        void sample_graph (
+            T& bn
+        )
+        {
+            using namespace bayes_node_utils;
+            for (unsigned long n = 0; n < bn.number_of_nodes(); ++n)
+            {
+                if (node_is_evidence(bn, n))
+                    continue;
+
+                samples.set_size(node_num_values(bn,n)); 
+                // obtain the probability distribution for this node
+                for (long i = 0; i < samples.nc(); ++i)
+                {
+                    set_node_value(bn, n, i);
+                    samples(i) = node_probability(bn, n);
+
+                    for (unsigned long j = 0; j < bn.node(n).number_of_children(); ++j)
+                        samples(i) *= node_probability(bn, bn.node(n).child(j).index());
+                }
+
+                //normalize samples
+                samples /= sum(samples);
+
+
+                // select a random point in the probability distribution
+                double prob = rnd.get_random_double();
+
+                // now find the point in the distribution this probability corresponds to
+                long j;
+                for (j = 0; j < samples.nc()-1; ++j)
+                {
+                    if (prob <= samples(j))
+                        break;
+                    else
+                        prob -= samples(j);
+                }
+
+                set_node_value(bn, n, j);
+            }
+        }
+
+
+    private:
+
+        template <
+            typename T
+            >
+        double node_probability (
+            const T& bn,
+            unsigned long n 
+        ) 
+        /*!
+            requires
+                - n < bn.number_of_nodes()
+            ensures
+                - computes the probability of node n having its current value given
+                  the current values of its parents in the network bn
+        !*/
+        {
+            v.clear();
+            for (unsigned long i = 0; i < bn.node(n).number_of_parents(); ++i)
+            {
+                v.add(bn.node(n).parent(i).index(), bn.node(n).parent(i).data.value());
+            }
+            return bn.node(n).data.table().probability(bn.node(n).data.value(), v);
+        }
+
+        assignment v;
+
+        dlib::rand rnd;
+        matrix<double,1> samples; 
+    };
+
+// ----------------------------------------------------------------------------------------
+
+    namespace bayesian_network_join_tree_helpers
+    {
+        class bnjt
+        {
+            /*!
+                this object is the base class used in this pimpl idiom
+            !*/
+        public:
+            virtual ~bnjt() {}
+
+            virtual const matrix<double,1> probability(
+                unsigned long idx
+            )  const = 0;
+        };
+
+        template <typename T, typename U>
+        class bnjt_impl : public bnjt
+        {
+            /*!
+                This object is the implementation in the pimpl idiom
+            !*/
+
+        public:
+
+            bnjt_impl (
+                const T& bn,
+                const U& join_tree
+            )
+            {
+                create_bayesian_network_join_tree(bn, join_tree, join_tree_values);
+
+                cliques.resize(bn.number_of_nodes());
+
+                // figure out which cliques contain each node
+                for (unsigned long i = 0; i < cliques.size(); ++i)
+                {
+                    // find the smallest clique that contains node with index i
+                    unsigned long smallest_clique = 0;
+                    unsigned long size = std::numeric_limits<unsigned long>::max();
+
+                    for (unsigned long n = 0; n < join_tree.number_of_nodes(); ++n)
+                    {
+                        if (join_tree.node(n).data.is_member(i) && join_tree.node(n).data.size() < size)
+                        {
+                            size = join_tree.node(n).data.size();
+                            smallest_clique = n;
+                        }
+                    }
+
+                    cliques[i] = smallest_clique;
+                }
+            }
+
+            virtual const matrix<double,1> probability(
+                unsigned long idx
+            ) const 
+            {
+                join_tree_values.node(cliques[idx]).data.marginalize(idx, table);
+                table.normalize();
+                var.clear();
+                var.add(idx);
+                dist.set_size(table.size());
+
+                // read the probabilities out of the table and into the row matrix
+                for (unsigned long i = 0; i < table.size(); ++i)
+                {
+                    var[idx] = i;
+                    dist(i) = table.probability(var); 
+                }
+
+                return dist;
+            }
+
+        private:
+
+            graph< joint_probability_table, joint_probability_table >::kernel_1a_c join_tree_values;
+            array<unsigned long> cliques;
+            mutable joint_probability_table table;
+            mutable assignment var;
+            mutable matrix<double,1> dist;
+           
+
+        // ----------------------------------------------------------------------------------------
+
+            template <typename set_type, typename node_type>
+            bool set_contains_all_parents_of_node (
+                const set_type& set,
+                const node_type& node
+            )
+            {
+                for (unsigned long i = 0; i < node.number_of_parents(); ++i)
+                {
+                    if (set.is_member(node.parent(i).index()) == false)
+                        return false;
+                }
+                return true;
+            }
+
+        // ----------------------------------------------------------------------------------------
+
+            template <
+                typename V
+                >
+            void pass_join_tree_message (
+                const U& join_tree,
+                V& bn_join_tree ,
+                unsigned long from,
+                unsigned long to
+            )
+            {
+                using namespace bayes_node_utils;
+                const typename U::edge_type& e = edge(join_tree, from, to);
+                typename V::edge_type& old_s = edge(bn_join_tree, from, to);
+
+                typedef typename V::edge_type joint_prob_table;
+
+                joint_prob_table new_s;
+                bn_join_tree.node(from).data.marginalize(e, new_s);
+
+                joint_probability_table temp(new_s);
+                // divide new_s by old_s and store the result in temp.
+                // if old_s is empty then that is the same as if it was all 1s
+                // so we don't have to do this if that is the case.
+                if (old_s.size() > 0)
+                {
+                    temp.reset();
+                    old_s.reset();
+                    while (temp.move_next())
+                    {
+                        old_s.move_next();
+                        if (old_s.element().value() != 0)
+                            temp.element().value()  /= old_s.element().value();
+                    }
+                }
+
+                // now multiply temp by d and store the results in d
+                joint_probability_table& d = bn_join_tree.node(to).data;
+                d.reset();
+                while (d.move_next())
+                {
+                    assignment a; 
+                    const assignment& asrc = d.element().key();
+                    asrc.reset();
+                    while (asrc.move_next())
+                    {
+                        if (e.is_member(asrc.element().key()))
+                            a.add(asrc.element().key(), asrc.element().value());
+                    }
+
+                    d.element().value() *= temp.probability(a);
+
+                }
+
+                // store new_s in old_s
+                new_s.swap(old_s);
+
+            }
+
+        // ----------------------------------------------------------------------------------------
+
+            template <
+                typename V
+                >
+            void create_bayesian_network_join_tree (
+                const T& bn,
+                const U& join_tree,
+                V& bn_join_tree 
+            )
+            /*!
+                requires
+                    - bn is a proper bayesian network
+                    - join_tree is the join tree for that bayesian network
+                ensures
+                    - bn_join_tree == the output of the join tree algorithm for bayesian network inference.  
+                      So each node in this graph contains a joint_probability_table for the clique
+                      in the corresponding node in the join_tree graph.
+            !*/
+            {
+                using namespace bayes_node_utils;
+                bn_join_tree.clear();
+                copy_graph_structure(join_tree, bn_join_tree);
+
+                // we need to keep track of which node is "in" each clique for the purposes of 
+                // initializing the tables in each clique.  So this vector will be used to do that
+                // and a value of join_tree.number_of_nodes() means that the node with 
+                // that index is unassigned.
+                std::vector<unsigned long> node_assigned_to(bn.number_of_nodes(),join_tree.number_of_nodes());
+
+                // populate evidence with all the evidence node indices and their values
+                dlib::map<unsigned long, unsigned long>::kernel_1b_c evidence;
+                for (unsigned long i = 0; i < bn.number_of_nodes(); ++i)
+                {
+                    if (node_is_evidence(bn, i))
+                    {
+                        unsigned long idx = i;
+                        unsigned long value = node_value(bn, i);
+                        evidence.add(idx,value);
+                    }
+                }
+
+
+                // initialize the bn join tree
+                for (unsigned long i = 0; i < join_tree.number_of_nodes(); ++i)
+                {
+                    bool contains_evidence = false;
+                    std::vector<unsigned long> indices;
+                    assignment value;
+
+                    // loop over all the nodes in this clique in the join tree.  In this loop 
+                    // we are making an assignment with all the values of the nodes it represents set to 0
+                    join_tree.node(i).data.reset();
+                    while (join_tree.node(i).data.move_next())
+                    {
+                        const unsigned long idx = join_tree.node(i).data.element();
+                        indices.push_back(idx);
+                        value.add(idx);
+
+                        if (evidence.is_in_domain(join_tree.node(i).data.element()))
+                            contains_evidence = true;
+                    }
+
+                    // now loop over all possible combinations of values that the nodes this 
+                    // clique in the join tree can take on.  We do this by counting by one through all
+                    // legal values
+                    bool more_assignments = true;
+                    while (more_assignments)
+                    {
+                        bn_join_tree.node(i).data.set_probability(value,1);
+
+                        // account for any evidence
+                        if (contains_evidence)
+                        {
+                            // loop over all the nodes in this cluster
+                            for (unsigned long j = 0; j < indices.size(); ++j)
+                            {
+                                // if the current node is an evidence node
+                                if (evidence.is_in_domain(indices[j]))
+                                {
+                                    const unsigned long idx = indices[j];
+                                    const unsigned long evidence_value = evidence[idx];
+                                    if (value[idx] != evidence_value)
+                                        bn_join_tree.node(i).data.set_probability(value , 0);
+                                }
+                            }
+                        }
+
+
+                        // now check if any of the nodes in this cluster also have their parents in this cluster
+                        join_tree.node(i).data.reset();
+                        while (join_tree.node(i).data.move_next())
+                        {
+                            const unsigned long idx = join_tree.node(i).data.element();
+                            // if this clique contains all the parents of this node and also hasn't
+                            // been assigned to another clique
+                            if (set_contains_all_parents_of_node(join_tree.node(i).data,  bn.node(idx)) && 
+                                (i == node_assigned_to[idx] || node_assigned_to[idx] == join_tree.number_of_nodes()) )
+                            {
+                                // note that this node is now assigned to this clique 
+                                node_assigned_to[idx] = i;
+                                // node idx has all its parents in the cluster
+                                assignment parent_values;
+                                for (unsigned long j = 0; j < bn.node(idx).number_of_parents(); ++j)
+                                {
+                                    const unsigned long pidx = bn.node(idx).parent(j).index();
+                                    parent_values.add(pidx, value[pidx]);
+                                }
+
+                                double temp = bn_join_tree.node(i).data.probability(value);
+                                bn_join_tree.node(i).data.set_probability(value, temp * node_probability(bn, idx, value[idx], parent_values));
+
+                            }
+                        }
+
+
+                        // now advance the value variable to its next possible state if there is one
+                        more_assignments = false;
+                        value.reset();
+                        while (value.move_next())
+                        {
+                            value.element().value() += 1;
+                            // if overflow
+                            if (value.element().value() == node_num_values(bn, value.element().key()))
+                            {
+                                value.element().value() = 0;
+                            }
+                            else
+                            {
+                                more_assignments = true;
+                                break;
+                            }
+                        }
+
+                    } // end while (more_assignments) 
+                } 
+
+
+
+
+                // the tree is now initialized.  Now all we need to do is perform the propagation and
+                // we are done
+                dlib::array<dlib::set<unsigned long>::compare_1b_c> remaining_msg_to_send;
+                dlib::array<dlib::set<unsigned long>::compare_1b_c> remaining_msg_to_receive;
+                remaining_msg_to_receive.resize(join_tree.number_of_nodes());
+                remaining_msg_to_send.resize(join_tree.number_of_nodes());
+                for (unsigned long i = 0; i < remaining_msg_to_receive.size(); ++i)
+                {
+                    for (unsigned long j = 0; j < join_tree.node(i).number_of_neighbors(); ++j)
+                    {
+                        const unsigned long idx = join_tree.node(i).neighbor(j).index();
+                        unsigned long temp;
+                        temp = idx; remaining_msg_to_receive[i].add(temp);
+                        temp = idx; remaining_msg_to_send[i].add(temp);
+                    }
+                }
+
+                // now remaining_msg_to_receive[i] contains all the nodes that node i hasn't yet received
+                // a message from.
+                // we will consider node 0 to be the root node.
+
+
+                bool message_sent = true;
+                while (message_sent)
+                {
+                    message_sent = false;
+                    for (unsigned long i = 1; i < remaining_msg_to_send.size(); ++i)
+                    {
+                        // if node i hasn't sent any messages but has received all but one then send a message to the one
+                        // node who hasn't sent i a message
+                        if (remaining_msg_to_send[i].size() == join_tree.node(i).number_of_neighbors() && remaining_msg_to_receive[i].size() == 1)
+                        {
+                            unsigned long to;
+                            // get the last remaining thing from this set
+                            remaining_msg_to_receive[i].remove_any(to);
+
+                            // send the message
+                            pass_join_tree_message(join_tree, bn_join_tree, i, to);
+
+                            // record that we sent this message
+                            remaining_msg_to_send[i].destroy(to);
+                            remaining_msg_to_receive[to].destroy(i);
+
+                            // put to back in since we still need to receive it
+                            remaining_msg_to_receive[i].add(to);
+                            message_sent = true;
+                        }
+                        else if (remaining_msg_to_receive[i].size() == 0 && remaining_msg_to_send[i].size() > 0)
+                        {
+                            unsigned long to;
+                            remaining_msg_to_send[i].remove_any(to);
+                            remaining_msg_to_receive[to].destroy(i);
+                            pass_join_tree_message(join_tree, bn_join_tree, i, to);
+                            message_sent = true;
+                        }
+                    }
+
+                    if (remaining_msg_to_receive[0].size() == 0)
+                    {
+                        // send a message to all of the root nodes neighbors unless we have already sent out he messages
+                        while (remaining_msg_to_send[0].size() > 0)
+                        {
+                            unsigned long to;
+                            remaining_msg_to_send[0].remove_any(to);
+                            remaining_msg_to_receive[to].destroy(0);
+                            pass_join_tree_message(join_tree, bn_join_tree, 0, to);
+                            message_sent = true;
+                        }
+                    }
+
+
+                }
+
+            }
+
+        };
+    }
+
+    class bayesian_network_join_tree : noncopyable
+    {
+        /*!
+            use the pimpl idiom to push the template arguments from the class level to the
+            constructor level
+        !*/
+
+    public:
+
+        template <
+            typename T,
+            typename U
+            >
+        bayesian_network_join_tree (
+            const T& bn,
+            const U& join_tree
+        )
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT( bn.number_of_nodes() > 0 ,
+                        "\tbayesian_network_join_tree::bayesian_network_join_tree(bn,join_tree)"
+                        << "\n\tYou have given an invalid bayesian network"
+                        << "\n\tthis:              " << this
+                    );
+
+            DLIB_ASSERT( is_join_tree(bn, join_tree) == true ,
+                        "\tbayesian_network_join_tree::bayesian_network_join_tree(bn,join_tree)"
+                        << "\n\tYou have given an invalid join tree for the supplied bayesian network"
+                        << "\n\tthis:              " << this
+                    );
+            DLIB_ASSERT( graph_contains_length_one_cycle(bn) == false,
+                        "\tbayesian_network_join_tree::bayesian_network_join_tree(bn,join_tree)"
+                        << "\n\tYou have given an invalid bayesian network"
+                        << "\n\tthis:              " << this
+                    );
+            DLIB_ASSERT( graph_is_connected(bn) == true,
+                        "\tbayesian_network_join_tree::bayesian_network_join_tree(bn,join_tree)"
+                        << "\n\tYou have given an invalid bayesian network"
+                        << "\n\tthis:              " << this
+                    );
+
+#ifdef ENABLE_ASSERTS
+            for (unsigned long i = 0; i < bn.number_of_nodes(); ++i)
+            {
+                DLIB_ASSERT(bayes_node_utils::node_cpt_filled_out(bn,i) == true,
+                        "\tbayesian_network_join_tree::bayesian_network_join_tree(bn,join_tree)"
+                        << "\n\tYou have given an invalid bayesian network. "
+                        << "\n\tYou must finish filling out the conditional_probability_table of node " << i
+                        << "\n\tthis:              " << this
+                    );
+            }
+#endif
+
+            impl.reset(new bayesian_network_join_tree_helpers::bnjt_impl<T,U>(bn, join_tree));
+            num_nodes = bn.number_of_nodes();
+        }
+
+        const matrix<double,1> probability(
+            unsigned long idx
+        ) const
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT( idx < number_of_nodes() ,
+                        "\tconst matrix<double,1> bayesian_network_join_tree::probability(idx)"
+                        << "\n\tYou have specified an invalid node index"
+                        << "\n\tidx:               " << idx 
+                        << "\n\tnumber_of_nodes(): " << number_of_nodes() 
+                        << "\n\tthis:              " << this
+                    );
+
+            return impl->probability(idx);
+        }
+
+        unsigned long number_of_nodes (
+        ) const { return num_nodes; }
+
+        void swap (
+            bayesian_network_join_tree& item
+        )
+        {
+            exchange(num_nodes, item.num_nodes);
+            impl.swap(item.impl);
+        }
+
+    private:
+
+        std::unique_ptr<bayesian_network_join_tree_helpers::bnjt> impl;
+        unsigned long num_nodes;
+
+    };
+
+    inline void swap (
+        bayesian_network_join_tree& a,
+        bayesian_network_join_tree& b
+    ) { a.swap(b); }
+
+}
+
+// ----------------------------------------------------------------------------------------
+
+#endif // DLIB_BAYES_UTILs_
+

dlib/bayes_utils/bayes_utils_abstract.h

+// Copyright (C) 2007  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#undef DLIB_BAYES_UTILs_ABSTRACT_
+#ifdef DLIB_BAYES_UTILs_ABSTRACT_
+
+#include "../algs.h"
+#include "../noncopyable.h"
+#include "../interfaces/enumerable.h"
+#include "../interfaces/map_pair.h"
+#include "../serialize.h"
+#include <iostream>
+
+namespace dlib
+{
+
+// ----------------------------------------------------------------------------------------
+
+    class assignment : public enumerable<map_pair<unsigned long, unsigned long> >
+    {
+        /*!
+            INITIAL VALUE
+                - size() == 0
+
+            ENUMERATION ORDER
+                The enumerator will iterate over the entries in the assignment in 
+                ascending order according to index values.  (i.e. the elements are 
+                enumerated in sorted order according to the value of their keys)
+
+            WHAT THIS OBJECT REPRESENTS
+                This object models an assignment of random variables to particular values.
+                It is used with the joint_probability_table and conditional_probability_table
+                objects to represent assignments of various random variables to actual values.
+
+                So for example, if you had a joint_probability_table that represented the
+                following table:
+                    P(A = 0, B = 0) = 0.2
+                    P(A = 0, B = 1) = 0.3
+                    P(A = 1, B = 0) = 0.1
+                    P(A = 1, B = 1) = 0.4
+
+                    Also lets define an enum so we have concrete index numbers for A and B
+                    enum { A = 0, B = 1};
+
+                Then you could query the value of P(A=1, B=0) as follows:
+                    assignment a;
+                    a.set(A, 1);
+                    a.set(B, 0);
+                    // and now it is the case that:
+                    table.probability(a) == 0.1 
+                    a[A] == 1
+                    a[B] == 0
+
+
+                Also note that when enumerating the elements of an assignment object
+                the key() refers to the index and the value() refers to the value at that
+                index. For example: 
+
+                // assume a is an assignment object
+                a.reset();
+                while (a.move_next())
+                {
+                    // in this loop it is always the case that:
+                    // a[a.element().key()] == a.element().value()
+                }
+        !*/
+
+    public:
+
+        assignment(
+        );
+        /*!
+            ensures
+                - this object is properly initialized
+        !*/
+
+        assignment(
+            const assignment& a
+        );
+        /*!
+            ensures
+                - #*this is a copy of a
+        !*/
+
+        assignment& operator = (
+            const assignment& rhs
+        );
+        /*!
+            ensures
+                - #*this is a copy of rhs
+                - returns *this
+        !*/
+
+        void clear(
+        );
+        /*!
+            ensures
+                - this object has been returned to its initial value
+        !*/
+
+        bool operator < (
+            const assignment& item
+        ) const;
+        /*!
+            ensures
+                - The exact functioning of this operator is undefined.  The only guarantee
+                  is that it establishes a total ordering on all possible assignment objects.
+                  In other words, this operator makes it so that you can use assignment
+                  objects in the associative containers but otherwise isn't of any 
+                  particular use.
+        !*/
+
+        bool has_index (
+            unsigned long idx
+        ) const;
+        /*!
+            ensures
+                - if (this assignment object has an entry for index idx) then
+                    - returns true
+                - else
+                    - returns false
+        !*/
+
+        void add (
+            unsigned long idx,
+            unsigned long value = 0
+        );
+        /*!
+            requires
+                - has_index(idx) == false
+            ensures
+                - #has_index(idx) == true 
+                - #(*this)[idx] == value 
+        !*/
+
+        void remove (
+            unsigned long idx
+        );
+        /*!
+            requires
+                - has_index(idx) == true 
+            ensures
+                - #has_index(idx) == false 
+        !*/
+
+        unsigned long& operator[] (
+            const long idx
+        );
+        /*!
+            requires
+                - has_index(idx) == true
+            ensures
+                - returns a reference to the value associated with index idx
+        !*/
+
+        const unsigned long& operator[] (
+            const long idx
+        ) const;
+        /*!
+            requires
+                - has_index(idx) == true
+            ensures
+                - returns a const reference to the value associated with index idx
+        !*/
+
+        void swap (
+            assignment& item
+        );
+        /*!
+            ensures
+                - swaps *this and item
+        !*/
+
+    };
+
+    inline void swap (
+        assignment& a,
+        assignment& b
+    ) { a.swap(b); }
+    /*!
+        provides a global swap
+    !*/
+
+    std::ostream& operator << (
+        std::ostream& out,
+        const assignment& a
+    );
+    /*!
+        ensures
+            - writes a to the given output stream in the following format:
+              (index1:value1, index2:value2, ..., indexN:valueN)
+    !*/
+
+    void serialize (
+        const assignment& item,
+        std::ostream& out 
+    );   
+    /*!
+        provides serialization support 
+    !*/
+
+    void deserialize (
+        assignment& item,
+        std::istream& in
+    );   
+    /*!
+        provides deserialization support 
+    !*/
+
+// ------------------------------------------------------------------------
+
+    class joint_probability_table : public enumerable<map_pair<assignment, double> >
+    {
+        /*!
+            INITIAL VALUE
+                - size() == 0
+
+            ENUMERATION ORDER
+                The enumerator will iterate over the entries in the probability table 
+                in no particular order but they will all be visited.
+
+            WHAT THIS OBJECT REPRESENTS
+                This object models a joint probability table.  That is, it models
+                the function p(X).  So this object models the probability of a particular
+                set of variables (referred to as X).
+        !*/
+
+    public:
+
+        joint_probability_table(
+        );
+        /*!
+            ensures
+                - this object is properly initialized
+        !*/
+
+        joint_probability_table (
+            const joint_probability_table& t
+        );
+        /*!
+            ensures
+                - this object is a copy of t
+        !*/
+
+        void clear(
+        );
+        /*!
+            ensures
+                - this object has its initial value
+        !*/
+
+        joint_probability_table& operator= (
+            const joint_probability_table& rhs
+        );
+        /*!
+            ensures
+                - this object is a copy of rhs
+                - returns a reference to *this
+        !*/
+
+        bool has_entry_for (
+            const assignment& a
+        ) const;
+        /*!
+            ensures
+                - if (this joint_probability_table has an entry for p(X = a)) then
+                    - returns true
+                - else
+                    - returns false
+        !*/
+
+        void set_probability (
+            const assignment& a,
+            double p
+        );
+        /*!
+            requires
+                - 0 <= p <= 1
+            ensures
+                - if (has_entry_for(a) == false) then
+                    - #size() == size() + 1
+                - #probability(a) == p
+                - #has_entry_for(a) == true
+        !*/
+
+        void add_probability (
+            const assignment& a,
+            double p
+        );
+        /*!
+            requires
+                - 0 <= p <= 1
+            ensures
+                - if (has_entry_for(a) == false) then
+                    - #size() == size() + 1
+                    - #probability(a) == p
+                - else
+                    - #probability(a) == min(probability(a) + p, 1.0)
+                      (i.e. does a saturating add)
+                - #has_entry_for(a) == true
+        !*/
+
+        const double probability (
+            const assignment& a
+        ) const;
+        /*!
+            ensures
+                - returns the probability p(X == a)
+        !*/
+
+        template <
+            typename T
+            >
+        void marginalize (
+            const T& vars,
+            joint_probability_table& output_table
+        ) const;
+        /*!
+            requires
+                - T is an implementation of set/set_kernel_abstract.h
+            ensures
+                - marginalizes *this by summing over all variables not in vars.  The
+                  result is stored in output_table.  
+        !*/
+
+        void marginalize (
+            const unsigned long var,
+            joint_probability_table& output_table
+        ) const;
+        /*!
+            ensures
+                - is identical to calling the above marginalize() function with a set
+                  that contains only var.  Or in other words, performs a marginalization
+                  with just one variable var.  So that output_table will contain a table giving
+                  the marginal probability of var all by itself.
+        !*/
+
+        void normalize (
+        );
+        /*!
+            ensures
+                - let sum == the sum of all the probabilities in this table
+                - after normalize() has finished it will be the case that the sum of all
+                  the entries in this table is 1.0.  This is accomplished by dividing all
+                  the entries by the sum described above.
+        !*/
+
+        void swap (
+            joint_probability_table& item
+        );
+        /*!
+            ensures
+                - swaps *this and item
+        !*/
+
+    };
+
+    inline void swap (
+        joint_probability_table& a,
+        joint_probability_table& b
+    ) { a.swap(b); }
+    /*!
+        provides a global swap
+    !*/
+
+    void serialize (
+        const joint_probability_table& item,
+        std::ostream& out 
+    );   
+    /*!
+        provides serialization support
+    !*/
+
+    void deserialize (
+        joint_probability_table& item,
+        std::istream& in
+    );   
+    /*!
+        provides deserialization support 
+    !*/
+
+// ----------------------------------------------------------------------------------------
+
+    class conditional_probability_table : noncopyable
+    {
+        /*!
+            INITIAL VALUE
+                - num_values() == 0
+                - has_value_for(x, y) == false for all values of x and y
+
+            WHAT THIS OBJECT REPRESENTS
+                This object models a conditional probability table.  That is, it models
+                the function p( X | parents).  So this object models the conditional 
+                probability of a particular variable (referred to as X) given another set 
+                of variables (referred to as parents).  
+        !*/
+
+    public:
+
+        conditional_probability_table(
+        );
+        /*!
+            ensures
+                - this object is properly initialized
+        !*/
+
+        void clear(
+        );
+        /*!
+            ensures
+                - this object has its initial value
+        !*/
+
+        void empty_table (
+        );
+        /*!
+            ensures
+                - for all possible v and p:
+                    - #has_entry_for(v,p) == false
+                  (i.e. this function clears out the table when you call it but doesn't 
+                  change the value of num_values())
+        !*/
+
+        void set_num_values (
+            unsigned long num
+        );
+        /*!
+            ensures
+                - #num_values() == num
+                - for all possible v and p:
+                    - #has_entry_for(v,p) == false
+                  (i.e. this function clears out the table when you call it)
+        !*/
+
+        unsigned long num_values (
+        ) const; 
+        /*!
+            ensures
+                - This object models the probability table p(X | parents).  This
+                  function returns the number of values X can take on.
+        !*/
+
+        bool has_entry_for (
+            unsigned long value,
+            const assignment& ps
+        ) const;
+        /*!
+            ensures
+                - if (this conditional_probability_table has an entry for p(X = value, parents = ps)) then
+                    - returns true
+                - else
+                    - returns false
+        !*/
+
+        void set_probability (
+            unsigned long value,
+            const assignment& ps,
+            double p
+        );
+        /*!
+            requires
+                - value < num_values()
+                - 0 <= p <= 1
+            ensures
+                - #probability(ps, value) == p
+                - #has_entry_for(value, ps) == true
+        !*/
+
+        double probability(
+            unsigned long value,
+            const assignment& ps
+        ) const;
+        /*!
+            requires
+                - value < num_values()
+                - has_entry_for(value, ps) == true
+            ensures
+                - returns the probability p( X = value | parents = ps). 
+        !*/
+
+        void swap (
+            conditional_probability_table& item
+        );
+        /*!
+            ensures
+                - swaps *this and item
+        !*/
+    };
+
+    inline void swap (
+        conditional_probability_table& a,
+        conditional_probability_table& b
+    ) { a.swap(b); }
+    /*!
+        provides a global swap
+    !*/
+
+    void serialize (
+        const conditional_probability_table& item,
+        std::ostream& out 
+    );   
+    /*!
+        provides serialization support
+    !*/
+
+    void deserialize (
+        conditional_probability_table& item,
+        std::istream& in
+    );   
+    /*!
+        provides deserialization support 
+    !*/
+
+// ------------------------------------------------------------------------
+// ------------------------------------------------------------------------
+// ------------------------------------------------------------------------
+
+    class bayes_node : noncopyable
+    {
+        /*!
+            INITIAL VALUE
+                - is_evidence() == false
+                - value() == 0
+                - table().num_values() == 0
+
+            WHAT THIS OBJECT REPRESENTS
+                This object represents a node in a bayesian network.  It is
+                intended to be used inside the dlib::directed_graph object to
+                represent bayesian networks.
+        !*/
+
+    public:
+        bayes_node (
+        );
+        /*!
+            ensures
+                - this object is properly initialized
+        !*/
+
+        unsigned long value (
+        ) const;
+        /*!
+            ensures
+                - returns the current value of this node
+        !*/
+
+        void set_value (
+            unsigned long new_value
+        );
+        /*!
+            requires
+                - new_value < table().num_values()
+            ensures
+                - #value() == new_value
+        !*/
+
+        conditional_probability_table& table (
+        );
+        /*!
+            ensures
+                - returns a reference to the conditional_probability_table associated with this node
+        !*/
+
+        const conditional_probability_table& table (
+        ) const;
+        /*!
+            ensures
+                - returns a const reference to the conditional_probability_table associated with this 
+                  node.
+        !*/
+
+        bool is_evidence (
+        ) const;
+        /*!
+            ensures
+                - if (this is an evidence node) then
+                    - returns true
+                - else
+                    - returns false
+        !*/
+
+        void set_as_nonevidence (
+        );
+        /*!
+            ensures
+                - #is_evidence() == false
+        !*/
+
+        void set_as_evidence (
+        );
+        /*!
+            ensures
+                - #is_evidence() == true 
+        !*/
+
+        void swap (
+            bayes_node& item
+        );
+        /*!
+            ensures
+                - swaps *this and item
+        !*/
+
+    };
+
+    inline void swap (
+        bayes_node& a,
+        bayes_node& b
+    ) { a.swap(b); }
+    /*!
+        provides a global swap
+    !*/
+
+    void serialize (
+        const bayes_node& item,
+        std::ostream& out 
+    );   
+    /*!
+        provides serialization support
+    !*/
+
+    void deserialize (
+        bayes_node& item,
+        std::istream& in
+    );   
+    /*!
+        provides deserialization support 
+    !*/
+
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+
+    /*
+        The following group of functions are convenience functions for manipulating 
+        bayes_node objects while they are inside a directed_graph.   These functions
+        also have additional requires clauses that, in debug mode, will protect you
+        from attempts to manipulate a bayesian network in an inappropriate way.
+    */
+
+    namespace bayes_node_utils
+    {
+
+        template <
+            typename T
+            >
+        void set_node_value (
+            T& bn,
+            unsigned long n,
+            unsigned long val
+        );
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+                - n < bn.number_of_nodes()
+                - val < node_num_values(bn, n)
+            ensures
+                - #bn.node(n).data.value() = val
+        !*/
+
+    // ------------------------------------------------------------------------------------
+
+        template <
+            typename T
+            >
+        unsigned long node_value (
+            const T& bn,
+            unsigned long n
+        );
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+                - n < bn.number_of_nodes()
+            ensures
+                - returns bn.node(n).data.value()
+        !*/
+
+    // ------------------------------------------------------------------------------------
+
+        template <
+            typename T
+            >
+        bool node_is_evidence (
+            const T& bn,
+            unsigned long n
+        ); 
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+                - n < bn.number_of_nodes()
+            ensures
+                - returns bn.node(n).data.is_evidence()
+        !*/
+
+    // ------------------------------------------------------------------------------------
+
+        template <
+            typename T
+            >
+        void set_node_as_evidence (
+            T& bn,
+            unsigned long n
+        );
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+                - n < bn.number_of_nodes()
+            ensures
+                - executes: bn.node(n).data.set_as_evidence()
+        !*/
+
+    // ------------------------------------------------------------------------------------
+
+        template <
+            typename T
+            >
+        void set_node_as_nonevidence (
+            T& bn,
+            unsigned long n
+        );
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+                - n < bn.number_of_nodes()
+            ensures
+                - executes: bn.node(n).data.set_as_nonevidence()
+        !*/
+
+    // ------------------------------------------------------------------------------------
+
+        template <
+            typename T
+            >
+        void set_node_num_values (
+            T& bn,
+            unsigned long n,
+            unsigned long num
+        ); 
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+                - n < bn.number_of_nodes()
+            ensures
+                - #bn.node(n).data.table().num_values() == num
+                  (i.e. sets the number of different values this node can take)
+        !*/
+
+    // ------------------------------------------------------------------------------------
+
+        template <
+            typename T
+            >
+        unsigned long node_num_values (
+            const T& bn,
+            unsigned long n
+        );
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+                - n < bn.number_of_nodes()
+            ensures
+                - returns bn.node(n).data.table().num_values() 
+                  (i.e. returns the number of different values this node can take)
+        !*/
+
+    // ------------------------------------------------------------------------------------
+
+        template <
+            typename T
+            >
+        const double node_probability (
+            const T& bn,
+            unsigned long n,
+            unsigned long value,
+            const assignment& parents 
+        );
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+                - n < bn.number_of_nodes()
+                - value < node_num_values(bn,n)
+                - parents.size() == bn.node(n).number_of_parents()
+                - if (parents.has_index(x)) then
+                    - bn.has_edge(x, n)
+                    - parents[x] < node_num_values(bn,x)
+            ensures
+                - returns bn.node(n).data.table().probability(value, parents)
+                  (i.e. returns the probability of node n having the given value when
+                  its parents have the given assignment)
+        !*/
+
+    // ------------------------------------------------------------------------------------
+
+        template <
+            typename T
+            >
+        const double set_node_probability (
+            const T& bn,
+            unsigned long n,
+            unsigned long value,
+            const assignment& parents,
+            double p
+        );
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+                - n < bn.number_of_nodes()
+                - value < node_num_values(bn,n)
+                - 0 <= p <= 1
+                - parents.size() == bn.node(n).number_of_parents()
+                - if (parents.has_index(x)) then
+                    - bn.has_edge(x, n)
+                    - parents[x] < node_num_values(bn,x)
+            ensures
+                - #bn.node(n).data.table().probability(value, parents) == p
+                  (i.e. sets the probability of node n having the given value when
+                  its parents have the given assignment to the probability p)
+        !*/
+
+    // ------------------------------------------------------------------------------------
+
+        template <typename T>
+        const assignment node_first_parent_assignment (
+            const T& bn,
+            unsigned long n
+        );
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+                - n < bn.number_of_nodes()
+            ensures
+                - returns an assignment A such that:
+                    - A.size() == bn.node(n).number_of_parents()
+                    - if (P is a parent of bn.node(n)) then
+                        - A.has_index(P)
+                        - A[P] == 0
+                    - I.e. this function returns an assignment that contains all
+                      the parents of the given node.  Also, all the values of each
+                      parent in the assignment is set to zero.
+        !*/
+
+    // ------------------------------------------------------------------------------------
+
+        template <typename T>
+        bool node_next_parent_assignment (
+            const T& bn,
+            unsigned long n,
+            assignment& A
+        );
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+                - n < bn.number_of_nodes()
+                - A.size() == bn.node(n).number_of_parents()
+                - if (A.has_index(x)) then
+                    - bn.has_edge(x, n)
+                    - A[x] < node_num_values(bn,x)
+            ensures
+                - The behavior of this function is defined by the following code:
+                  assignment a(node_first_parent_assignment(bn,n);
+                  do {
+                    // this loop loops over all possible parent assignments
+                    // of the node bn.node(n).  Each time through the loop variable a
+                    // will be the next assignment.
+                  } while (node_next_parent_assignment(bn,n,a))
+        !*/
+
+    // ------------------------------------------------------------------------------------
+
+        template <typename T>
+        bool node_cpt_filled_out (
+            const T& bn,
+            unsigned long n
+        );
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+                - n < bn.number_of_nodes()
+            ensures
+                - if (the conditional_probability_table bn.node(n).data.table() is
+                  fully filled out for this node) then
+                    - returns true
+                    - This means that each parent assignment for the given node
+                      along with all possible values of this node shows up in the
+                      table.
+                    - It also means that all the probabilities conditioned on the
+                      same parent assignment sum to 1.0
+                - else
+                    - returns false
+        !*/
+
+    }
+
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+
+    class bayesian_network_gibbs_sampler : noncopyable
+    {
+        /*!
+            INITIAL VALUE
+                This object has no state
+
+            WHAT THIS OBJECT REPRESENTS
+                This object performs Markov Chain Monte Carlo sampling of a bayesian
+                network using the Gibbs sampling technique. 
+
+                Note that this object is limited to only bayesian networks that 
+                don't contain deterministic nodes.  That is, incorrect results may
+                be computed if this object is used when the bayesian network contains 
+                any nodes that have a probability of 1 in their conditional probability
+                tables for any event.  So don't use this object for networks with 
+                deterministic nodes.
+        !*/
+    public:
+
+        bayesian_network_gibbs_sampler (
+        );
+        /*!
+            ensures
+                - this object is properly initialized
+        !*/
+
+        template <
+            typename T
+            >
+        void sample_graph (
+            T& bn
+        )
+        /*!
+            requires
+                - T is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - T::type == bayes_node
+            ensures
+                - modifies randomly (via the Gibbs sampling technique) samples all the nodes
+                  in the network and updates their values with the newly sampled values
+        !*/
+    };
+
+// ----------------------------------------------------------------------------------------
+
+    class bayesian_network_join_tree : noncopyable
+    {
+        /*!
+            WHAT THIS OBJECT REPRESENTS
+                This object represents an implementation of the join tree algorithm
+                for inference in bayesian networks.  It doesn't have any mutable state.
+                To you use you just give it a directed_graph that contains a bayesian 
+                network and a graph object that contains that networks corresponding
+                join tree.  Then you may query this object to determine the probabilities
+                of any variables in the original bayesian network.
+        !*/
+
+    public:
+
+        template <
+            typename bn_type,
+            typename join_tree_type 
+            >
+        bayesian_network_join_tree (
+            const bn_type& bn,
+            const join_tree_type& join_tree
+        );
+        /*!
+            requires
+                - bn_type is an implementation of directed_graph/directed_graph_kernel_abstract.h
+                - bn_type::type == bayes_node
+                - join_tree_type is an implementation of graph/graph_kernel_abstract.h
+                - join_tree_type::type is an implementation of set/set_compare_abstract.h and
+                  this set type contains unsigned long objects. 
+                - join_tree_type::edge_type is an implementation of set/set_compare_abstract.h and
+                  this set type contains unsigned long objects. 
+                - is_join_tree(bn, join_tree) == true
+                - bn == a valid bayesian network with all its conditional probability tables
+                  filled out
+                - for all valid n:
+                    - node_cpt_filled_out(bn,n) == true
+                - graph_contains_length_one_cycle(bn) == false
+                - graph_is_connected(bn) == true
+                - bn.number_of_nodes() > 0
+            ensures
+                - this object is properly initialized
+        !*/
+
+        unsigned long number_of_nodes (
+        ) const;
+        /*!
+            ensures
+                - returns the number of nodes in the bayesian network that this
+                  object was instantiated from.
+        !*/
+
+        const matrix<double,1> probability(
+            unsigned long idx
+        ) const;
+        /*!
+            requires
+                - idx < number_of_nodes()
+            ensures
+                - returns the probability distribution for the node with index idx that was in the bayesian 
+                  network that *this was instantiated from.  Let D represent this distribution, then:
+                    - D.nc() == the number of values the node idx ranges over
+                    - D.nr() == 1 
+                    - D(i) == the probability of node idx taking on the value i 
+        !*/
+
+        void swap (
+            bayesian_network_join_tree& item
+        );
+        /*!
+            ensures
+                - swaps *this with item
+        !*/
+
+    };
+
+    inline void swap (
+        bayesian_network_join_tree& a,
+        bayesian_network_join_tree& b
+    ) { a.swap(b); }
+    /*!
+        provides a global swap
+    !*/
+
+// ----------------------------------------------------------------------------------------
+
+}
+
+#endif // DLIB_BAYES_UTILs_ABSTRACT_
+
+

dlib/bigint.h

+// Copyright (C) 2003  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_BIGINt_
+#define DLIB_BIGINt_
+
+#include "bigint/bigint_kernel_1.h"
+#include "bigint/bigint_kernel_2.h"
+#include "bigint/bigint_kernel_c.h"
+
+
+
+
+namespace dlib
+{
+
+
+    class bigint
+    {
+        bigint() {}
+
+
+    public:
+        
+        //----------- kernels ---------------
+
+        // kernel_1a        
+        typedef     bigint_kernel_1
+                    kernel_1a;
+        typedef     bigint_kernel_c<kernel_1a>
+                    kernel_1a_c;
+          
+        // kernel_2a        
+        typedef     bigint_kernel_2
+                    kernel_2a;
+        typedef     bigint_kernel_c<kernel_2a>
+                    kernel_2a_c;
+          
+
+    };
+}
+
+#endif // DLIB_BIGINt_
+

dlib/bigint/bigint_kernel_1.cpp

+// Copyright (C) 2003  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+#ifndef DLIB_BIGINT_KERNEL_1_CPp_
+#define DLIB_BIGINT_KERNEL_1_CPp_
+#include "bigint_kernel_1.h"
+
+#include <iostream>
+
+namespace dlib
+{
+
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+    // member/friend function definitions
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1::
+    bigint_kernel_1 (
+    ) :
+        slack(25),
+        data(new data_record(slack))
+    {}
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1::
+    bigint_kernel_1 (
+        uint32 value
+    ) :
+        slack(25),
+        data(new data_record(slack))
+    {
+        *(data->number) = static_cast<uint16>(value&0xFFFF);
+        *(data->number+1) = static_cast<uint16>((value>>16)&0xFFFF);
+        if (*(data->number+1) != 0)
+            data->digits_used = 2;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1::
+    bigint_kernel_1 (
+        const bigint_kernel_1& item
+    ) :
+        slack(25),
+        data(item.data)
+    {
+        data->references += 1;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1::
+    ~bigint_kernel_1 (
+    )
+    {
+        if (data->references == 1)
+        {
+            delete data;
+        }
+        else
+        {
+            data->references -= 1;
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 bigint_kernel_1::
+    operator+ (
+        const bigint_kernel_1& rhs
+    ) const
+    {
+        data_record* temp = new data_record (
+                    std::max(rhs.data->digits_used,data->digits_used) + slack
+                    );
+        long_add(data,rhs.data,temp);
+        return bigint_kernel_1(temp,0);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator+= (
+        const bigint_kernel_1& rhs
+    )
+    {
+        // if there are other references to our data
+        if (data->references != 1)
+        {
+            data_record* temp = new data_record(std::max(data->digits_used,rhs.data->digits_used)+slack);
+            data->references -= 1;   
+            long_add(data,rhs.data,temp);
+            data = temp;
+        }
+        // if data is not big enough for the result
+        else if (data->size <= std::max(data->digits_used,rhs.data->digits_used))
+        {
+            data_record* temp = new data_record(std::max(data->digits_used,rhs.data->digits_used)+slack);
+            long_add(data,rhs.data,temp);
+            delete data;
+            data = temp;
+        }
+        // there is enough size and no references
+        else
+        {
+            long_add(data,rhs.data,data);
+        }
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 bigint_kernel_1::
+    operator- (
+        const bigint_kernel_1& rhs
+    ) const
+    {
+        data_record* temp = new data_record (
+                    data->digits_used + slack
+                    );
+        long_sub(data,rhs.data,temp);
+        return bigint_kernel_1(temp,0);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator-= (
+        const bigint_kernel_1& rhs
+    )
+    {
+        // if there are other references to this data 
+        if (data->references != 1)
+        {
+            data_record* temp = new data_record(data->digits_used+slack);
+            data->references -= 1;
+            long_sub(data,rhs.data,temp);
+            data = temp;
+        }
+        else
+        {
+            long_sub(data,rhs.data,data);
+        }
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 bigint_kernel_1::
+    operator* (
+        const bigint_kernel_1& rhs
+    ) const
+    {
+        data_record* temp = new data_record (
+                    data->digits_used + rhs.data->digits_used + slack
+                    );
+        long_mul(data,rhs.data,temp);
+        return bigint_kernel_1(temp,0);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator*= (
+        const bigint_kernel_1& rhs
+    )
+    {
+        // create a data_record to store the result of the multiplication in
+        data_record* temp = new data_record(rhs.data->digits_used+data->digits_used+slack);        
+        long_mul(data,rhs.data,temp);
+
+        // if there are other references to data
+        if (data->references != 1)
+        {
+            data->references -= 1;
+        }
+        else
+        {
+            delete data;
+        }
+        data = temp;
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 bigint_kernel_1::
+    operator/ (
+        const bigint_kernel_1& rhs
+    ) const
+    {
+        data_record* temp = new data_record(data->digits_used+slack);
+        data_record* remainder;
+        try {
+            remainder = new data_record(data->digits_used+slack);           
+        } catch (...) { delete temp; throw; }
+
+        long_div(data,rhs.data,temp,remainder);
+        delete remainder;
+    
+
+        return bigint_kernel_1(temp,0);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator/= (
+        const bigint_kernel_1& rhs
+    )
+    {
+
+        data_record* temp = new data_record(data->digits_used+slack);
+        data_record* remainder;
+        try {
+            remainder = new data_record(data->digits_used+slack);
+        } catch (...) { delete temp; throw; }    
+
+        long_div(data,rhs.data,temp,remainder);
+
+        // check if there are other references to data
+        if (data->references != 1)
+        {
+            data->references -= 1;
+        }
+        // if there are no references to data then it must be deleted
+        else
+        {
+            delete data;
+        }
+        data = temp;
+        delete remainder;
+
+        
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 bigint_kernel_1::
+    operator% (
+        const bigint_kernel_1& rhs
+    ) const
+    {
+        data_record* temp = new data_record(data->digits_used+slack);
+        data_record* remainder;
+        try {
+            remainder = new data_record(data->digits_used+slack);
+        } catch (...) { delete temp; throw; }
+
+        long_div(data,rhs.data,temp,remainder);
+        delete temp;
+        return bigint_kernel_1(remainder,0);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator%= (
+        const bigint_kernel_1& rhs
+    )
+    {
+        data_record* temp = new data_record(data->digits_used+slack);
+        data_record* remainder;
+        try {
+            remainder = new data_record(data->digits_used+slack);
+        } catch (...) { delete temp; throw; }
+
+        long_div(data,rhs.data,temp,remainder);
+
+        // check if there are other references to data
+        if (data->references != 1)
+        {
+            data->references -= 1;
+        }
+        // if there are no references to data then it must be deleted
+        else
+        {
+            delete data;
+        }
+        data = remainder;
+        delete temp;
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bool bigint_kernel_1::
+    operator < (
+        const bigint_kernel_1& rhs
+    ) const
+    {
+        return is_less_than(data,rhs.data);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bool bigint_kernel_1::
+    operator == (
+        const bigint_kernel_1& rhs
+    ) const
+    {
+        return is_equal_to(data,rhs.data);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator= (
+        const bigint_kernel_1& rhs
+    )
+    {
+        if (this == &rhs)
+            return *this;
+
+        // if we have the only reference to our data then delete it
+        if (data->references == 1)
+        {
+            delete data;
+            data = rhs.data;
+            data->references += 1;
+        }
+        else
+        {
+            data->references -= 1;
+            data = rhs.data;
+            data->references += 1;
+        }
+
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    std::ostream& operator<< (
+        std::ostream& out_,
+        const bigint_kernel_1& rhs
+    )
+    {
+        std::ostream out(out_.rdbuf());
+
+        typedef bigint_kernel_1 bigint;
+        
+        bigint::data_record* temp = new bigint::data_record(*rhs.data,0);
+
+
+
+        // get a char array big enough to hold the number in ascii format
+        char* str;
+        try {
+            str = new char[(rhs.data->digits_used)*5+10];
+        } catch (...) { delete temp; throw; }
+
+        char* str_start = str;
+        str += (rhs.data->digits_used)*5+9;
+        *str = 0; --str;
+
+
+        uint16 remainder;
+        rhs.short_div(temp,10000,temp,remainder);
+
+        // pull the digits out of remainder
+        char a = remainder % 10 + '0';
+        remainder /= 10;
+        char b = remainder % 10 + '0';
+        remainder /= 10;
+        char c = remainder % 10 + '0';
+        remainder /= 10;
+        char d = remainder % 10 + '0';
+        remainder /= 10;
+
+
+        *str = a; --str;
+        *str = b; --str;
+        *str = c; --str;
+        *str = d; --str;
+
+
+        // keep looping until temp represents zero
+        while (temp->digits_used != 1 || *(temp->number) != 0)
+        {            
+            rhs.short_div(temp,10000,temp,remainder);
+
+            // pull the digits out of remainder
+            char a = remainder % 10 + '0';
+            remainder /= 10;
+            char b = remainder % 10 + '0';
+            remainder /= 10;
+            char c = remainder % 10 + '0';
+            remainder /= 10;
+            char d = remainder % 10 + '0';
+            remainder /= 10;
+
+            *str = a; --str;
+            *str = b; --str;
+            *str = c; --str;
+            *str = d; --str;              
+        }
+
+        // throw away and extra leading zeros
+        ++str;
+        if (*str == '0')
+            ++str;
+        if (*str == '0')
+            ++str;
+        if (*str == '0')
+            ++str;
+
+
+        
+
+        out << str;
+        delete [] str_start;
+        delete temp;
+        return out_;
+
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    std::istream& operator>> (
+        std::istream& in_,
+        bigint_kernel_1& rhs
+    )
+    {
+        std::istream in(in_.rdbuf());
+
+        // ignore any leading whitespaces
+        while (in.peek() == ' ' || in.peek() == '\t' || in.peek() == '\n')
+        {
+            in.get();
+        }
+
+        // if the first digit is not an integer then this is an error
+        if ( !(in.peek() >= '0' && in.peek() <= '9'))
+        {
+            in_.clear(std::ios::failbit);
+            return in_;
+        }
+
+        int num_read;
+        bigint_kernel_1 temp;
+        do
+        {
+
+            // try to get 4 chars from in
+            num_read = 1;
+            char a = 0;
+            char b = 0; 
+            char c = 0;
+            char d = 0;
+
+            if (in.peek() >= '0' && in.peek() <= '9')
+            {
+                num_read *= 10;
+                a = in.get();
+            }
+            if (in.peek() >= '0' && in.peek() <= '9')
+            {
+                num_read *= 10;
+                b = in.get();
+            }
+            if (in.peek() >= '0' && in.peek() <= '9')
+            {
+                num_read *= 10;
+                c = in.get();
+            }
+            if (in.peek() >= '0' && in.peek() <= '9')
+            {
+                num_read *= 10;
+                d = in.get();
+            }
+            
+            // merge the for digits into an uint16
+            uint16 num = 0;
+            if (a != 0)
+            {
+                num = a - '0';
+            }
+            if (b != 0)
+            {
+                num *= 10;
+                num += b - '0';
+            }
+            if (c != 0)
+            {
+                num *= 10;
+                num += c - '0';
+            }
+            if (d != 0)
+            {
+                num *= 10;
+                num += d - '0';
+            }
+
+
+            if (num_read != 1)
+            {
+                // shift the digits in temp left by the number of new digits we just read
+                temp *= num_read;
+                // add in new digits
+                temp += num;
+            }
+
+        } while (num_read == 10000);
+
+
+        rhs = temp;
+        return in_;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 operator+ (
+        uint16 lhs,
+        const bigint_kernel_1& rhs
+    )
+    {
+        typedef bigint_kernel_1 bigint;
+        bigint::data_record* temp = new bigint::data_record
+                (rhs.data->digits_used+rhs.slack);
+
+        rhs.short_add(rhs.data,lhs,temp);
+        return bigint_kernel_1(temp,0);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 operator+ (
+        const bigint_kernel_1& lhs,
+        uint16 rhs
+    )
+    {
+        typedef bigint_kernel_1 bigint;
+        bigint::data_record* temp = new bigint::data_record
+                (lhs.data->digits_used+lhs.slack);
+
+        lhs.short_add(lhs.data,rhs,temp);
+        return bigint_kernel_1(temp,0);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator+= (
+        uint16 rhs
+    )
+    {
+        // if there are other references to this data 
+        if (data->references != 1)
+        {
+            data_record* temp = new data_record(data->digits_used+slack);
+            data->references -= 1;    
+            short_add(data,rhs,temp);
+            data = temp;
+        }
+        // or if we need to enlarge data then do so
+        else if (data->digits_used == data->size)
+        {
+            data_record* temp = new data_record(data->digits_used+slack);
+            short_add(data,rhs,temp);
+            delete data;
+            data = temp;
+        }
+        // or if there is plenty of space and no references
+        else
+        {
+            short_add(data,rhs,data);
+        }
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 operator- (
+        uint16 lhs,
+        const bigint_kernel_1& rhs
+    )
+    {
+        typedef bigint_kernel_1 bigint;
+        bigint::data_record* temp = new bigint::data_record(rhs.slack);
+
+        *(temp->number) = lhs - *(rhs.data->number);
+
+        return bigint_kernel_1(temp,0);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 operator- (
+        const bigint_kernel_1& lhs,
+        uint16 rhs
+    )
+    {
+        typedef bigint_kernel_1 bigint;
+        bigint::data_record* temp = new bigint::data_record
+                (lhs.data->digits_used+lhs.slack);
+
+        lhs.short_sub(lhs.data,rhs,temp);
+        return bigint_kernel_1(temp,0);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator-= (
+        uint16 rhs
+    )
+    {
+        // if there are other references to this data 
+        if (data->references != 1)
+        {
+            data_record* temp = new data_record(data->digits_used+slack);
+            data->references -= 1;
+            short_sub(data,rhs,temp);
+            data = temp;
+        }
+        else
+        {
+            short_sub(data,rhs,data);
+        }
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 operator* (
+        uint16 lhs,
+        const bigint_kernel_1& rhs
+    )
+    {
+        typedef bigint_kernel_1 bigint;
+        bigint::data_record* temp = new bigint::data_record
+                (rhs.data->digits_used+rhs.slack);
+
+        rhs.short_mul(rhs.data,lhs,temp);
+        return bigint_kernel_1(temp,0);        
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 operator* (
+        const bigint_kernel_1& lhs,
+        uint16 rhs
+    )
+    {
+        typedef bigint_kernel_1 bigint;
+        bigint::data_record* temp = new bigint::data_record
+                (lhs.data->digits_used+lhs.slack);
+
+        lhs.short_mul(lhs.data,rhs,temp);
+        return bigint_kernel_1(temp,0);  
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator*= (
+        uint16 rhs
+    )
+    {
+        // if there are other references to this data 
+        if (data->references != 1)
+        {
+            data_record* temp = new data_record(data->digits_used+slack);
+            data->references -= 1;
+            short_mul(data,rhs,temp);
+            data = temp;
+        }
+        // or if we need to enlarge data
+        else if (data->digits_used == data->size)
+        {
+            data_record* temp = new data_record(data->digits_used+slack);
+            short_mul(data,rhs,temp);
+            delete data;
+            data = temp;
+        }
+        else
+        {
+            short_mul(data,rhs,data);
+        }
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 operator/ (
+        uint16 lhs,
+        const bigint_kernel_1& rhs
+    )
+    {
+        typedef bigint_kernel_1 bigint;
+        bigint::data_record* temp = new bigint::data_record(rhs.slack);
+
+        // if rhs might not be bigger than lhs
+        if (rhs.data->digits_used == 1)
+        {
+            *(temp->number) = lhs/ *(rhs.data->number);
+        }
+        
+        return bigint_kernel_1(temp,0);  
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 operator/ (
+        const bigint_kernel_1& lhs,
+        uint16 rhs
+    )
+    {
+        typedef bigint_kernel_1 bigint;
+        bigint::data_record* temp = new bigint::data_record
+                (lhs.data->digits_used+lhs.slack);
+
+        uint16 remainder;
+        lhs.short_div(lhs.data,rhs,temp,remainder);
+        return bigint_kernel_1(temp,0);  
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator/= (
+        uint16 rhs
+    )
+    {
+        uint16 remainder;
+        // if there are other references to this data
+        if (data->references != 1)
+        {
+            data_record* temp = new data_record(data->digits_used+slack);
+            data->references -= 1;
+            short_div(data,rhs,temp,remainder);    
+            data = temp;
+        }
+        else
+        {
+            short_div(data,rhs,data,remainder);
+        }
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 operator% (
+        uint16 lhs,
+        const bigint_kernel_1& rhs
+    )
+    {
+        typedef bigint_kernel_1 bigint;
+        // temp is zero by default
+        bigint::data_record* temp = new bigint::data_record(rhs.slack);
+
+        if (rhs.data->digits_used == 1)
+        {
+            // if rhs is just an uint16 inside then perform the modulus
+            *(temp->number) = lhs % *(rhs.data->number);
+        }
+        else
+        {
+            // if rhs is bigger than lhs then the answer is lhs
+            *(temp->number) = lhs;
+        }
+        
+        return bigint_kernel_1(temp,0);  
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 operator% (
+        const bigint_kernel_1& lhs,
+        uint16 rhs
+    )
+    {
+        typedef bigint_kernel_1 bigint;
+        bigint::data_record* temp = new bigint::data_record(lhs.data->digits_used+lhs.slack);
+
+        uint16 remainder;
+
+        lhs.short_div(lhs.data,rhs,temp,remainder);
+        temp->digits_used = 1;
+        *(temp->number) = remainder;
+        return bigint_kernel_1(temp,0);          
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator%= (
+        uint16 rhs
+    )
+    {
+        uint16 remainder;
+        // if there are other references to this data
+        if (data->references != 1)
+        {
+            data_record* temp = new data_record(data->digits_used+slack);
+            data->references -= 1;
+            short_div(data,rhs,temp,remainder);
+            data = temp;
+        }
+        else
+        {
+            short_div(data,rhs,data,remainder);
+        }
+
+        data->digits_used = 1;
+        *(data->number) = remainder;
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bool operator < (
+        uint16 lhs,
+        const bigint_kernel_1& rhs
+    )
+    {
+        return (rhs.data->digits_used > 1 || lhs < *(rhs.data->number) );
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bool operator < (
+        const bigint_kernel_1& lhs,
+        uint16 rhs
+    )
+    {
+        return (lhs.data->digits_used == 1 && *(lhs.data->number) < rhs);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bool operator == (
+        const bigint_kernel_1& lhs,
+        uint16 rhs
+    )
+    {
+        return (lhs.data->digits_used == 1 && *(lhs.data->number) == rhs);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bool operator == (
+        uint16 lhs,
+        const bigint_kernel_1& rhs
+    )
+    {
+        return (rhs.data->digits_used == 1 && *(rhs.data->number) == lhs);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator= (
+        uint16 rhs
+    )
+    {
+        // check if there are other references to our data
+        if (data->references != 1)
+        {
+            data->references -= 1;
+            try {
+                data = new data_record(slack);
+            } catch (...) { data->references += 1; throw; }
+        }
+        else
+        {
+            data->digits_used = 1;
+        }
+        
+        *(data->number) = rhs;
+
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator++ (
+    )
+    {
+        // if there are other references to this data then make a copy of it
+        if (data->references != 1)
+        {
+            data_record* temp = new data_record(data->digits_used+slack);
+            data->references -= 1;
+            increment(data,temp);
+            data = temp;
+        }
+        // or if we need to enlarge data then do so
+        else if (data->digits_used == data->size)
+        {
+            data_record* temp = new data_record(data->digits_used+slack);
+            increment(data,temp);
+            delete data;
+            data = temp;
+        }
+        else
+        {
+            increment(data,data);
+        }
+
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 bigint_kernel_1::
+    operator++ (
+        int
+    )
+    {
+        data_record* temp; // this is the copy of temp we will return in the end
+         
+        data_record* temp2 = new data_record(data->digits_used+slack);
+        increment(data,temp2);
+        
+        temp = data;
+        data = temp2;
+
+        return bigint_kernel_1(temp,0);
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bigint_kernel_1& bigint_kernel_1::
+    operator-- (
+    )
+    {
+        // if there are other references to this data 
+        if (data->references != 1)
+        {
+            data_record* temp = new data_record(data->digits_used+slack);
+            data->references -= 1;
+            decrement(data,temp);
+            data = temp;
+        }
+        else
+        {
+            decrement(data,data);
+        }
+
+        return *this;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    const bigint_kernel_1 bigint_kernel_1::
+    operator-- (
+        int
+    )
+    {
+        data_record* temp; // this is the copy of temp we will return in the end
+         
+        data_record* temp2 = new data_record(data->digits_used+slack);
+        decrement(data,temp2);
+        
+        temp = data;
+        data = temp2;
+
+        return bigint_kernel_1(temp,0);
+    }
+
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+    // private member function definitions
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
+
+    void bigint_kernel_1::
+    short_add (
+        const data_record* data,        
+        uint16 value,
+        data_record* result
+    ) const
+    {
+        // put value into the carry part of temp
+        uint32 temp = value;
+        temp <<= 16;
+
+        
+        const uint16* number = data->number;
+        const uint16* end = number + data->digits_used; // one past the end of number
+        uint16* r = result->number;
+
+        while (number != end)
+        {
+            // add *number and the current carry
+            temp = *number + (temp>>16);
+            // put the low word of temp into *r
+            *r = static_cast<uint16>(temp & 0xFFFF);
+
+            ++number;
+            ++r;
+        }
+
+        // if there is a final carry
+        if ((temp>>16) != 0)
+        {
+            result->digits_used = data->digits_used + 1;
+            // store the carry in the most significant digit of the result
+            *r = static_cast<uint16>(temp>>16); 
+        }
+        else
+        {
+            result->digits_used = data->digits_used;
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void bigint_kernel_1::
+    short_sub (
+        const data_record* data,        
+        uint16 value,
+        data_record* result
+    ) const
+    {
+        
+
+        const uint16* number = data->number;
+        const uint16* end = number + data->digits_used - 1;
+        uint16* r = result->number;
+
+        uint32 temp = *number - value;
+
+        // put the low word of temp into *data 
+        *r = static_cast<uint16>(temp & 0xFFFF);
+
+        
+        while (number != end)
+        {
+            ++number;
+            ++r;
+
+            // subtract the carry from *number 
+            temp = *number - (temp>>31);
+
+            // put the low word of temp into *r 
+            *r = static_cast<uint16>(temp & 0xFFFF);
+        }
+
+        // if we lost a digit in the subtraction
+        if (*r == 0)
+        {
+            if (data->digits_used == 1)
+                result->digits_used = 1;
+            else
+                result->digits_used = data->digits_used - 1;
+        }
+        else
+        {
+            result->digits_used = data->digits_used;
+        }
+
+
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void bigint_kernel_1::
+    short_mul (
+        const data_record* data,        
+        uint16 value,
+        data_record* result
+    ) const
+    {
+        
+        uint32 temp = 0;
+
+
+        const uint16* number = data->number;        
+        uint16* r = result->number;
+        const uint16* end = r + data->digits_used;
+
+
+
+        while ( r != end)
+        {
+
+            // multiply *data and value and add in the carry
+            temp = *number*(uint32)value + (temp>>16);
+
+            // put the low word of temp into *data
+            *r = static_cast<uint16>(temp & 0xFFFF);
+
+            ++number;
+            ++r;
+        }
+
+        // if there is a final carry
+        if ((temp>>16) != 0)
+        {
+            result->digits_used = data->digits_used + 1;
+            // put the final carry into the most significant digit of the result
+            *r = static_cast<uint16>(temp>>16);
+        }
+        else
+        {
+            result->digits_used = data->digits_used;
+        }
+
+
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void bigint_kernel_1::
+    short_div (
+        const data_record* data,        
+        uint16 value,   
+        data_record* result,
+        uint16& rem
+    ) const
+    {
+        
+        uint16 remainder = 0;
+        uint32 temp;
+
+        
+
+        const uint16* number = data->number + data->digits_used - 1;
+        const uint16* end = number - data->digits_used;
+        uint16* r = result->number + data->digits_used - 1;
+
+
+        // if we are losing a digit in this division
+        if (*number < value)
+        {
+            if (data->digits_used == 1)
+                result->digits_used = 1;
+            else
+                result->digits_used = data->digits_used - 1;
+        }
+        else
+        {
+            result->digits_used = data->digits_used;
+        }
+
+
+        // perform the actual division
+        while (number != end)
+        {
+           
+            temp = *number + (((uint32)remainder)<<16);
+
+            *r = static_cast<uint16>(temp/value);
+            remainder = static_cast<uint16>(temp%value);
+
+            --number;
+            --r;
+        }
+
+        rem = remainder;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void bigint_kernel_1::
+    long_add (
+        const data_record* lhs,
+        const data_record* rhs,
+        data_record* result
+    ) const
+    {
+        // put value into the carry part of temp
+        uint32 temp=0;        
+
+        uint16* min_num;  // the number with the least digits used
+        uint16* max_num;  // the number with the most digits used
+        uint16* min_end;  // one past the end of min_num
+        uint16* max_end;  // one past the end of max_num
+        uint16* r = result->number;
+
+        uint32 max_digits_used;
+        if (lhs->digits_used < rhs->digits_used)
+        {
+            max_digits_used = rhs->digits_used;
+            min_num = lhs->number;
+            max_num = rhs->number;
+            min_end = min_num + lhs->digits_used;
+            max_end = max_num + rhs->digits_used;
+        }
+        else
+        {
+            max_digits_used = lhs->digits_used;
+            min_num = rhs->number;
+            max_num = lhs->number;
+            min_end = min_num + rhs->digits_used;
+            max_end = max_num + lhs->digits_used;
+        }
+
+        
+
+
+        while (min_num != min_end)
+        {
+            // add *min_num, *max_num and the current carry
+            temp = *min_num + *max_num + (temp>>16);
+            // put the low word of temp into *r
+            *r = static_cast<uint16>(temp & 0xFFFF);
+
+            ++min_num;
+            ++max_num;
+            ++r;
+        }
+
+
+        while (max_num != max_end)
+        {
+            // add *max_num and the current carry
+            temp = *max_num + (temp>>16);
+            // put the low word of temp into *r
+            *r = static_cast<uint16>(temp & 0xFFFF);
+
+            ++max_num;
+            ++r;
+        }        
+
+        // check if there was a final carry
+        if ((temp>>16) != 0)
+        {
+            result->digits_used = max_digits_used + 1;
+            // put the carry into the most significant digit in the result
+            *r = static_cast<uint16>(temp>>16);
+        }
+        else
+        {
+            result->digits_used = max_digits_used;
+        }
+
+        
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void bigint_kernel_1::
+    long_sub (
+        const data_record* lhs,
+        const data_record* rhs,
+        data_record* result
+    ) const
+    {
+
+
+        const uint16* number1 = lhs->number;
+        const uint16* number2 = rhs->number;
+        const uint16* end = number2 + rhs->digits_used;
+        uint16* r = result->number;
+
+
+
+        uint32 temp =0;
+
+        
+        while (number2 != end)
+        {
+
+            // subtract *number2 from *number1 and then subtract any carry
+            temp = *number1 - *number2 - (temp>>31);
+
+            // put the low word of temp into *r 
+            *r = static_cast<uint16>(temp & 0xFFFF);
+
+            ++number1;
+            ++number2;
+            ++r;
+        }
+
+        end = lhs->number + lhs->digits_used;
+        while (number1 != end)
+        {
+
+            // subtract the carry from *number1 
+            temp = *number1 - (temp>>31);
+
+            // put the low word of temp into *r 
+            *r = static_cast<uint16>(temp & 0xFFFF);
+
+            ++number1;
+            ++r;
+        }
+
+        result->digits_used = lhs->digits_used;
+        // adjust the number of digits used appropriately 
+        --r;
+        while (*r == 0 && result->digits_used > 1)
+        {
+            --r;
+            --result->digits_used;
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void bigint_kernel_1::
+    long_div (
+        const data_record* lhs,
+        const data_record* rhs,
+        data_record* result,
+        data_record* remainder
+    ) const
+    {
+        // zero result
+        result->digits_used = 1;
+        *(result->number) = 0;
+
+        uint16* a;
+        uint16* b;
+        uint16* end;
+
+        // copy lhs into remainder
+        remainder->digits_used = lhs->digits_used;
+        a = remainder->number;
+        end = a + remainder->digits_used;
+        b = lhs->number;
+        while (a != end)
+        {
+            *a = *b;
+            ++a;
+            ++b;
+        }
+
+
+        // if rhs is bigger than lhs then result == 0 and remainder == lhs
+        // so then we can quit right now
+        if (is_less_than(lhs,rhs))
+        {
+            return;            
+        }
+
+
+        // make a temporary number
+        data_record temp(lhs->digits_used + slack);
+
+
+        // shift rhs left until it is one shift away from being larger than lhs and
+        // put the number of left shifts necessary into shifts
+        uint32 shifts; 
+        shifts = (lhs->digits_used - rhs->digits_used) * 16;
+
+        shift_left(rhs,&temp,shifts);
+
+
+        // while (lhs > temp)
+        while (is_less_than(&temp,lhs))
+        {
+            shift_left(&temp,&temp,1);
+            ++shifts;
+        }
+        // make sure lhs isn't smaller than temp
+        while (is_less_than(lhs,&temp))
+        {
+            shift_right(&temp,&temp);
+            --shifts;
+        }
+
+        
+        
+        // we want to execute the loop shifts +1 times
+        ++shifts;
+        while (shifts != 0)
+        {
+            shift_left(result,result,1);
+            // if (temp <= remainder)
+            if (!is_less_than(remainder,&temp))
+            {
+                long_sub(remainder,&temp,remainder);
+                
+                // increment result
+                uint16* r = result->number;
+                uint16* end = r + result->digits_used;
+                while (true)
+                {
+                    ++(*r);
+                    // if there was no carry then we are done
+                    if (*r != 0)
+                        break;
+
+                    ++r;
+
+                    // if we hit the end of r and there is still a carry then
+                    // the next digit of r is 1 and there is one more digit used
+                    if (r == end)
+                    {
+                        *r = 1;
+                        ++(result->digits_used);
+                        break;
+                    }
+                }
+            }
+            shift_right(&temp,&temp);
+            --shifts;
+        }
+        
+        
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void bigint_kernel_1::
+    long_mul (
+        const data_record* lhs,
+        const data_record* rhs,
+        data_record* result
+    ) const
+    {
+        // make result be zero
+        result->digits_used = 1;
+        *(result->number) = 0;
+        
+
+        const data_record* aa;
+        const data_record* bb;
+
+        if (lhs->digits_used < rhs->digits_used)
+        {
+            // make copies of lhs and rhs and give them an appropriate amount of
+            // extra memory so there won't be any overflows
+            aa = lhs;
+            bb = rhs;
+        }
+        else
+        {
+            // make copies of lhs and rhs and give them an appropriate amount of
+            // extra memory so there won't be any overflows
+            aa = rhs;
+            bb = lhs;
+        }
+        // this is where we actually copy lhs and rhs
+        data_record b(*bb,aa->digits_used+slack); // the larger(approximately) of lhs and rhs
+
+
+        uint32 shift_value = 0;
+        uint16* anum = aa->number;
+        uint16* end = anum + aa->digits_used;
+        while (anum != end )
+        {
+            uint16 bit = 0x0001;
+ 
+            for (int i = 0; i < 16; ++i)
+            {
+                // if the specified bit of a is 1
+                if ((*anum & bit) != 0)
+                {
+                    shift_left(&b,&b,shift_value);
+                    shift_value = 0;
+                    long_add(&b,result,result);
+                }
+                ++shift_value;
+                bit <<= 1;
+            }
+
+            ++anum;                        
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void bigint_kernel_1::
+    shift_left (
+        const data_record* data,
+        data_record* result,
+        uint32 shift_amount
+    ) const
+    {
+        uint32 offset = shift_amount/16;
+        shift_amount &= 0xf;  // same as shift_amount %= 16;
+
+        uint16* r = result->number + data->digits_used + offset; // result
+        uint16* end = data->number;
+        uint16* s = end + data->digits_used; // source
+        const uint32 temp = 16 - shift_amount;
+
+        *r = (*(--s) >> temp);
+        // set the number of digits used in the result
+        // if the upper bits from *s were zero then don't count this first word
+        if (*r == 0)
+        {
+            result->digits_used = data->digits_used + offset;
+        }
+        else
+        {
+            result->digits_used = data->digits_used + offset + 1;
+        }
+        --r;
+
+        while (s != end)
+        {
+            *r = ((*s << shift_amount) | ( *(s-1) >> temp));
+            --r;
+            --s;
+        }
+        *r = *s << shift_amount;
+
+        // now zero the rest of the result
+        end = result->number;
+        while (r != end)
+            *(--r) = 0;
+
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void bigint_kernel_1::
+    shift_right (
+        const data_record* data,
+        data_record* result
+    ) const
+    {
+
+            uint16* r = result->number; // result
+            uint16* s = data->number; // source
+            uint16* end = s + data->digits_used - 1;
+
+            while (s != end)
+            {
+                *r = (*s >> 1) | (*(s+1) << 15);
+                ++r;
+                ++s;
+            }
+            *r = *s >> 1;
+
+
+            // calculate the new number for digits_used
+            if (*r == 0)
+            {
+                if (data->digits_used != 1)
+                    result->digits_used = data->digits_used - 1;
+                else
+                    result->digits_used = 1;
+            }
+            else
+            {
+                result->digits_used = data->digits_used;
+            }
+  
+
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bool bigint_kernel_1::
+    is_less_than (
+        const data_record* lhs,
+        const data_record* rhs
+    ) const
+    {
+        uint32 lhs_digits_used = lhs->digits_used;
+        uint32 rhs_digits_used = rhs->digits_used;
+
+        // if lhs is definitely less than rhs
+        if (lhs_digits_used < rhs_digits_used )
+            return true;
+        // if lhs is definitely greater than rhs
+        else if (lhs_digits_used > rhs_digits_used)
+            return false;
+        else 
+        {
+            uint16* end = lhs->number;
+            uint16* l = end         + lhs_digits_used;
+            uint16* r = rhs->number + rhs_digits_used;
+            
+            while (l != end)
+            {
+                --l;
+                --r;
+                if (*l < *r)
+                    return true;
+                else if (*l > *r)
+                    return false;
+            }
+
+            // at this point we know that they are equal
+            return false;
+        }
+
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    bool bigint_kernel_1::
+    is_equal_to (
+        const data_record* lhs,
+        const data_record* rhs
+    ) const
+    {
+        // if lhs and rhs are definitely not equal
+        if (lhs->digits_used != rhs->digits_used )
+        {
+            return false;
+        }
+        else 
+        {            
+            uint16* l = lhs->number;
+            uint16* r = rhs->number;
+            uint16* end = l + lhs->digits_used;
+            
+            while (l != end)
+            {
+                if (*l != *r)
+                    return false;
+                ++l;
+                ++r;
+            }
+
+            // at this point we know that they are equal
+            return true;
+        }
+
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void bigint_kernel_1::
+    increment (
+        const data_record* source,
+        data_record* dest
+    ) const
+    {
+        uint16* s = source->number;
+        uint16* d = dest->number;
+        uint16* end = s + source->digits_used;
+        while (true)
+        {
+            *d = *s + 1;
+
+            // if there was no carry then break out of the loop
+            if (*d != 0)
+            {
+                dest->digits_used = source->digits_used;
+
+                // copy the rest of the digits over to d
+                ++d; ++s;
+                while (s != end)
+                {
+                    *d = *s;
+                    ++d;
+                    ++s;
+                }
+
+                break;
+            }
+            
+
+            ++s;            
+
+            // if we have hit the end of s and there was a carry up to this point
+            // then just make the next digit 1 and add one to the digits used
+            if (s == end)
+            {
+                ++d;
+                dest->digits_used = source->digits_used + 1;
+                *d = 1;
+                break;
+            }
+
+            ++d;
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void bigint_kernel_1::
+    decrement (
+        const data_record* source,
+        data_record* dest
+    ) const
+    {
+        uint16* s = source->number;
+        uint16* d = dest->number;
+        uint16* end = s + source->digits_used;
+        while (true)
+        {
+            *d = *s - 1;
+
+            // if there was no carry then break out of the loop
+            if (*d != 0xFFFF)
+            {
+                // if we lost a digit in the subtraction 
+                if (*d == 0 && s+1 == end)
+                {
+                    if (source->digits_used == 1)
+                        dest->digits_used = 1;
+                    else
+                        dest->digits_used = source->digits_used - 1;
+                }
+                else
+                {
+                    dest->digits_used = source->digits_used;
+                }
+                break;
+            }
+            else
+            {
+                ++d;
+                ++s;
+            }
+
+        }
+
+        // copy the rest of the digits over to d
+        ++d;
+        ++s;
+        while (s != end)
+        {
+            *d = *s;
+            ++d;
+            ++s;
+        }
+    }
+
+// ----------------------------------------------------------------------------------------
+
+}
+#endif // DLIB_BIGINT_KERNEL_1_CPp_
+