Problem: integer overflow when calculating sizes (may happen e.g. with very large images) (#1148)

* Problem: integer overflow when calculating sizes (may happen e.g. with very large images)
Solution: change some types from (unsigned) long to size_t

# Conflicts:
#	dlib/dnn/tensor.h

* Fix the fact that std::numeric_limits<unsigned long>::max() isn't always the same number

* Revert serialization changes

* Review fix: use long long instead of size_t

* From long to long long all the way

* Change more types to (hopefully) make the compiler happy

* Change many more types to size_t

* Change even more types to size_t

* Minor type changes

dlib/array/array_kernel.h

@@ -106,7 +106,7 @@ namespace dlib
         }
 
         explicit array (
-            unsigned long new_size
+            size_t new_size
         ) :
             array_size(0),
             max_array_size(0),
@@ -125,22 +125,22 @@ namespace dlib
         );
 
         inline const T& operator[] (
-            unsigned long pos
+            size_t pos
         ) const;
 
         inline T& operator[] (
-            unsigned long pos
+            size_t pos
         );
 
         void set_size (
-            unsigned long size
+            size_t size
         );
 
-        inline unsigned long max_size(
+        inline size_t max_size(
         ) const;
 
         void set_max_size(
-            unsigned long max
+            size_t max
         );
 
         void swap (
@@ -148,7 +148,7 @@ namespace dlib
         );
 
         // functions from the enumerable interface
-        inline unsigned long size (
+        inline size_t size (
         ) const;
 
         inline bool at_start (
@@ -173,7 +173,7 @@ namespace dlib
         );
 
         void resize (
-            unsigned long new_size
+            size_t new_size
         );
 
         const T& back (
@@ -209,8 +209,8 @@ namespace dlib
         typename mem_manager::template rebind<T>::other pool;
 
         // data members
-        unsigned long array_size;
-        unsigned long max_array_size;
+        size_t array_size;
+        size_t max_array_size;
         T* array_elements;
 
         mutable T* pos;
@@ -248,7 +248,7 @@ namespace dlib
             serialize(item.max_size(),out);
             serialize(item.size(),out);
 
-            for (unsigned long i = 0; i < item.size(); ++i)
+            for (size_t i = 0; i < item.size(); ++i)
                 serialize(item[i],out);
         }
         catch (serialization_error e)
@@ -268,12 +268,12 @@ namespace dlib
     {
         try
         {
-            unsigned long max_size, size;
+            size_t max_size, size;
             deserialize(max_size,in);
             deserialize(size,in);
             item.set_max_size(max_size);
             item.set_size(size);
-            for (unsigned long i = 0; i < size; ++i)
+            for (size_t i = 0; i < size; ++i)
                 deserialize(item[i],in);
         }
         catch (serialization_error e)
@@ -333,7 +333,7 @@ namespace dlib
         >
     const T& array<T,mem_manager>::
     operator[] (
-        unsigned long pos
+        size_t pos
     ) const
     {
         // make sure requires clause is not broken
@@ -356,7 +356,7 @@ namespace dlib
         >
     T& array<T,mem_manager>::
     operator[] (
-        unsigned long pos
+        size_t pos
     ) 
     {
         // make sure requires clause is not broken
@@ -379,7 +379,7 @@ namespace dlib
         >
     void array<T,mem_manager>::
     set_size (
-        unsigned long size
+        size_t size
     )
     {
         // make sure requires clause is not broken
@@ -405,7 +405,7 @@ namespace dlib
         typename T,
         typename mem_manager
         >
-    unsigned long array<T,mem_manager>::
+    size_t array<T,mem_manager>::
     size (
     ) const
     {
@@ -420,7 +420,7 @@ namespace dlib
         >
     void array<T,mem_manager>::
     set_max_size(
-        unsigned long max
+        size_t max
     )
     {
         reset();
@@ -458,7 +458,7 @@ namespace dlib
         typename T,
         typename mem_manager
         >
-    unsigned long array<T,mem_manager>::
+    size_t array<T,mem_manager>::
     max_size (
     ) const
     {
@@ -476,8 +476,8 @@ namespace dlib
         array<T,mem_manager>& item
     )
     {
-        unsigned long    array_size_temp        = item.array_size;
-        unsigned long    max_array_size_temp    = item.max_array_size;
+        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;
@@ -646,7 +646,7 @@ namespace dlib
         >
     void array<T,mem_manager>::
     resize (
-        unsigned long new_size
+        size_t new_size
     )
     {
         if (this->max_size() < new_size)
@@ -654,7 +654,7 @@ namespace dlib
             array temp;
             temp.set_max_size(new_size);
             temp.set_size(new_size);
-            for (unsigned long i = 0; i < this->size(); ++i)
+            for (size_t i = 0; i < this->size(); ++i)
             {
                 exchange((*this)[i],temp[i]);
             }
@@ -769,7 +769,7 @@ namespace dlib
             array temp;
             temp.set_max_size(this->size()*2 + 1);
             temp.set_size(this->size()+1);
-            for (unsigned long i = 0; i < this->size(); ++i)
+            for (size_t i = 0; i < this->size(); ++i)
             {
                 exchange((*this)[i],temp[i]);
             }

dlib/array/array_kernel_abstract.h

@@ -66,7 +66,7 @@ namespace dlib
             !*/
 
             explicit array (
-                unsigned long new_size
+                size_t new_size
             );
             /*!
                 ensures 
@@ -116,7 +116,7 @@ namespace dlib
             !*/
 
             const T& operator[] (
-                unsigned long pos
+                size_t pos
             ) const;
             /*!
                 requires
@@ -126,7 +126,7 @@ namespace dlib
             !*/
             
             T& operator[] (
-                unsigned long pos
+                size_t pos
             );
             /*!
                 requires
@@ -136,7 +136,7 @@ namespace dlib
             !*/
 
             void set_size (
-                unsigned long size
+                size_t size
             );
             /*!
                 requires
@@ -155,7 +155,7 @@ namespace dlib
                         if it does throw then the call to set_size() has no effect    
             !*/
 
-            unsigned long max_size(
+            size_t max_size(
             ) const;
             /*!
                 ensures
@@ -163,7 +163,7 @@ namespace dlib
             !*/
 
             void set_max_size(
-                unsigned long max
+                size_t max
             );
             /*!
                 ensures
@@ -198,7 +198,7 @@ namespace dlib
             !*/
 
             void resize (
-                unsigned long new_size
+                size_t new_size
             );
             /*!
                 ensures

dlib/array2d/array2d_kernel.h

@@ -312,8 +312,8 @@ namespace dlib
             }
         }
 
-        unsigned long size (
-        ) const { return static_cast<unsigned long>(nc_ * nr_); }
+        size_t size (
+        ) const { return static_cast<size_t>(nc_) * static_cast<size_t>(nr_); }
 
         long width_step (
         ) const

dlib/bayes_utils/bayes_utils.h

@@ -356,7 +356,7 @@ namespace dlib
             table.clear();
         }
 
-        unsigned long size () const { return table.size(); }
+        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() 

dlib/binary_search_tree/binary_search_tree_kernel_1.h

@@ -168,7 +168,7 @@ namespace dlib
             );
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             bool at_start (
@@ -597,7 +597,7 @@ namespace dlib
         typename mem_manager,
         typename compare
         >   
-    unsigned long binary_search_tree_kernel_1<domain,range,mem_manager,compare>::
+    size_t binary_search_tree_kernel_1<domain,range,mem_manager,compare>::
     size (
     ) const
     {

dlib/binary_search_tree/binary_search_tree_kernel_2.h

@@ -169,7 +169,7 @@ namespace dlib
             );
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             bool at_start (
@@ -543,7 +543,7 @@ namespace dlib
         typename mem_manager,
         typename compare
         >
-    unsigned long binary_search_tree_kernel_2<domain,range,mem_manager,compare>::
+    size_t binary_search_tree_kernel_2<domain,range,mem_manager,compare>::
     size (
     ) const
     {

dlib/cmd_line_parser/cmd_line_parser_kernel_1.h

@@ -305,7 +305,7 @@ namespace dlib
         bool move_next (
         ) const { return options.move_next(); }
 
-        unsigned long size (
+        size_t size (
         ) const { return options.size(); }
 
     private:

dlib/disjoint_subsets/disjoint_subsets.h

@@ -34,7 +34,7 @@ namespace dlib
             }
         }
 
-        unsigned long size (
+        size_t size (
         ) const noexcept
         {
             return items.size();

dlib/disjoint_subsets/disjoint_subsets_abstract.h

@@ -44,7 +44,7 @@ namespace dlib
                       (i.e. this object contains new_size subsets, each containing exactly one element)
         !*/
 
-        unsigned long size (
+        size_t size (
         ) const noexcept;
         /*!
             ensures

dlib/disjoint_subsets/disjoint_subsets_sized.h

@@ -34,7 +34,7 @@ namespace dlib
             number_of_sets = new_size;
         }
 
-        unsigned long size (
+        size_t size (
         ) const noexcept
         {
             return disjoint_subsets_.size();

dlib/disjoint_subsets/disjoint_subsets_sized_abstract.h

@@ -50,7 +50,7 @@ namespace dlib
                     - #get_size_of_set(i) == 1
         !*/
 
-        unsigned long size (
+        size_t size (
         ) const noexcept;
         /*!
             ensures

dlib/dnn/cpu_dlib.cpp

@@ -1639,17 +1639,17 @@ namespace dlib
             float* g = grad.host();
             const float x_scale = (grad.nc()-1)/(float)std::max<long>((gradient_input.nc()-1),1);
             const float y_scale = (grad.nr()-1)/(float)std::max<long>((gradient_input.nr()-1),1);
-            for (long samp = 0; samp < gradient_input.num_samples(); ++samp)
+            for (long long samp = 0; samp < gradient_input.num_samples(); ++samp)
             {
-                for (long k = 0; k < gradient_input.k(); ++k)
+                for (long long k = 0; k < gradient_input.k(); ++k)
                 {
-                    for (long r = 0; r < gradient_input.nr(); ++r)
+                    for (long long r = 0; r < gradient_input.nr(); ++r)
                     {
                         const float y = r*y_scale;
                         const long long top    = static_cast<long long>(std::floor(y));
                         const long long bottom = std::min(top+1, grad.nr()-1);
                         const float tb_frac = y - top;
-                        for (long c = 0; c < gradient_input.nc(); ++c)
+                        for (long long c = 0; c < gradient_input.nc(); ++c)
                         {
                             const float x = c*x_scale;
                             const long long left   = static_cast<long long>(std::floor(x));

dlib/dnn/tensor_abstract.h

@@ -467,7 +467,7 @@ namespace dlib
         !*/
 
         explicit resizable_tensor(
-            long long n_, long long g k_ = 1, long long nr_ = 1, long long nc_ = 1
+            long long n_, long long k_ = 1, long long nr_ = 1, long long nc_ = 1
         );
         /*!
             requires

dlib/geometry/border_enumerator.h

@@ -125,7 +125,7 @@ namespace dlib
             return false;
         }
 
-        unsigned long size (
+        size_t size (
         ) const
         {
             return rect.area() - inner_rect.area();

dlib/geometry/border_enumerator_abstract.h

@@ -99,7 +99,7 @@ namespace dlib
                 - returns false if there are no more elements in the container
         !*/
 
-        unsigned long size (
+        size_t size (
         ) const;
         /*!
             ensures

dlib/gui_widgets/base_widgets.cpp

@@ -1399,7 +1399,7 @@ namespace dlib
 
 // ----------------------------------------------------------------------------------------
 
-    unsigned long widget_group::
+    size_t widget_group::
     size (
     ) const 
     {  
@@ -1578,7 +1578,7 @@ namespace dlib
 
 // ----------------------------------------------------------------------------------------
 
-    unsigned long popup_menu::
+    size_t popup_menu::
     size (
     ) const
     { 

dlib/gui_widgets/base_widgets.h

@@ -329,7 +329,7 @@ namespace dlib
             const drawable& widget
         );
 
-        unsigned long size (
+        size_t size (
         ) const; 
 
         void set_pos (
@@ -2039,7 +2039,7 @@ namespace dlib
             unsigned long idx
         );
 
-        unsigned long size (
+        size_t size (
         ) const;
 
         void clear (

dlib/gui_widgets/base_widgets_abstract.h

@@ -967,7 +967,7 @@ namespace dlib
                       widgets in this group and the upper left corner of get_rect(). 
         !*/
 
-        unsigned long size (
+        size_t size (
         ) const;
         /*!
             ensures
@@ -1561,7 +1561,7 @@ namespace dlib
                 - the menu_item in this with the index idx has been disabled
         !*/
 
-        unsigned long size (
+        size_t size (
         ) const;
         /*!
             ensures

dlib/gui_widgets/widgets.cpp

@@ -2470,7 +2470,7 @@ namespace dlib
 // ----------------------------------------------------------------------------------------
 
     template <typename S>
-    unsigned long list_box<S>::
+    size_t list_box<S>::
     size (
     ) const
     {

dlib/gui_widgets/widgets.h

@@ -1792,7 +1792,7 @@ namespace dlib
         bool move_next (
         ) const;
 
-        unsigned long size (
+        size_t size (
         ) const;
 
         unsigned long get_selected (