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/hash_map/hash_map_kernel_1.h

@@ -100,7 +100,7 @@ namespace dlib
             );
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             inline bool at_start (
@@ -328,7 +328,7 @@ namespace dlib
         typename hash_table,
         typename mem_manager
         >
-    unsigned long hash_map_kernel_1<domain,range,expnum,hash_table,mem_manager>::
+    size_t hash_map_kernel_1<domain,range,expnum,hash_table,mem_manager>::
     size (
     ) const
     {

dlib/hash_set/hash_set_kernel_1.h

@@ -85,7 +85,7 @@ namespace dlib
             );
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             inline bool at_start (
@@ -266,7 +266,7 @@ namespace dlib
         typename hash_table,
         typename mem_manager
         >
-    unsigned long hash_set_kernel_1<T,expnum,hash_table,mem_manager>::
+    size_t hash_set_kernel_1<T,expnum,hash_table,mem_manager>::
     size (
     ) const
     {

dlib/hash_table/hash_table_kernel_1.h

@@ -145,7 +145,7 @@ namespace dlib
             );
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             bool at_start (
@@ -336,7 +336,7 @@ namespace dlib
         typename mem_manager,
         typename compare
         >
-    unsigned long hash_table_kernel_1<domain,range,mem_manager,compare>::
+    size_t hash_table_kernel_1<domain,range,mem_manager,compare>::
     size(
     ) const
     {

dlib/hash_table/hash_table_kernel_2.h

@@ -116,7 +116,7 @@ namespace dlib
             );
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             inline bool at_start (
@@ -266,7 +266,7 @@ namespace dlib
         typename mem_manager,
         typename compare
         >
-    unsigned long hash_table_kernel_2<domain,range,bst_base,mem_manager,compare>::
+    size_t hash_table_kernel_2<domain,range,bst_base,mem_manager,compare>::
     size(
     ) const
     {

dlib/image_keypoint/binned_vector_feature_image.h

@@ -55,7 +55,7 @@ namespace dlib
             const image_type& img
         );
 
-        inline unsigned long size (
+        inline size_t size (
         ) const;
 
         inline long nr (
@@ -280,7 +280,7 @@ namespace dlib
         typename feature_extractor,
         typename hash_function_type
         >
-    unsigned long binned_vector_feature_image<feature_extractor,hash_function_type>::
+    size_t binned_vector_feature_image<feature_extractor,hash_function_type>::
     size (
     ) const
     {

dlib/image_keypoint/binned_vector_feature_image_abstract.h

@@ -132,7 +132,7 @@ namespace dlib
                   operator() as defined below.
         !*/
 
-        unsigned long size (
+        size_t size (
         ) const;
         /*!
             ensures

dlib/image_keypoint/fine_hog_image.h

@@ -73,8 +73,8 @@ namespace dlib
         inline void unload(
         ) { clear(); }
 
-        inline unsigned long size (
-        ) const { return static_cast<unsigned long>(nr()*nc()); }
+        inline size_t size (
+        ) const { return static_cast<size_t>(nr()*nc()); }
 
         inline long nr (
         ) const { return num_block_rows; }

dlib/image_keypoint/fine_hog_image_abstract.h

@@ -132,7 +132,7 @@ namespace dlib
                   Both sequence 1 and sequence 2 should have the same effect on H.  
         !*/
 
-        inline unsigned long size (
+        inline size_t size (
         ) const;
         /*!
             ensures

dlib/image_keypoint/hashed_feature_image.h

@@ -56,7 +56,7 @@ namespace dlib
             const image_type& img
         );
 
-        inline unsigned long size (
+        inline size_t size (
         ) const;
 
         inline long nr (
@@ -325,7 +325,7 @@ namespace dlib
         typename feature_extractor,
         typename hash_function_type
         >
-    unsigned long hashed_feature_image<feature_extractor,hash_function_type>::
+    size_t hashed_feature_image<feature_extractor,hash_function_type>::
     size (
     ) const
     {

dlib/image_keypoint/hashed_feature_image_abstract.h

@@ -125,7 +125,7 @@ namespace dlib
                   operator() as defined below.
         !*/
 
-        unsigned long size (
+        size_t size (
         ) const;
         /*!
             ensures

dlib/image_keypoint/hog.h

@@ -89,8 +89,8 @@ namespace dlib
         inline void unload(
         ) { clear(); }
 
-        inline unsigned long size (
-        ) const { return static_cast<unsigned long>(nr()*nc()); }
+        inline size_t size (
+        ) const { return static_cast<size_t>(nr()*nc()); }
 
         inline long nr (
         ) const { return num_block_rows; }

dlib/image_keypoint/hog_abstract.h

@@ -188,7 +188,7 @@ namespace dlib
                   Both sequence 1 and sequence 2 should have the same effect on H.  
         !*/
 
-        inline unsigned long size (
+        inline size_t size (
         ) const;
         /*!
             ensures

dlib/image_keypoint/nearest_neighbor_feature_image.h

@@ -53,7 +53,7 @@ namespace dlib
             const image_type& img
         );
 
-        inline unsigned long size (
+        inline size_t size (
         ) const;
 
         inline long nr (
@@ -250,7 +250,7 @@ namespace dlib
     template <
         typename feature_extractor
         >
-    unsigned long nearest_neighbor_feature_image<feature_extractor>::
+    size_t nearest_neighbor_feature_image<feature_extractor>::
     size (
     ) const
     {

dlib/image_keypoint/nearest_neighbor_feature_image_abstract.h

@@ -102,7 +102,7 @@ namespace dlib
                   operator() as defined below.
         !*/
 
-        inline unsigned long size (
+        inline size_t size (
         ) const;
         /*!
             ensures

dlib/image_keypoint/poly_image.h

@@ -193,7 +193,7 @@ namespace dlib
             num_cols = 0;
         }
 
-        inline unsigned long size (
+        inline size_t size (
         ) const { return static_cast<unsigned long>(nr()*nc()); }
 
         inline long nr (

dlib/image_keypoint/poly_image_abstract.h

@@ -197,7 +197,7 @@ namespace dlib
                   Both sequence 1 and sequence 2 should have the same effect on H.  
         !*/
 
-        inline unsigned long size (
+        inline size_t size (
         ) const; 
         /*!
             ensures

dlib/interfaces/enumerable.h

@@ -104,7 +104,7 @@ namespace dlib
                 - returns false if there are no more elements in the container
         !*/
 
-        virtual unsigned long size (
+        virtual size_t size (
         ) const = 0;
         /*!
             ensures

dlib/interfaces/remover.h

@@ -54,7 +54,7 @@ namespace dlib
                         - #at_start() == true
             !*/
 
-            virtual unsigned long size (
+            virtual size_t size (
             ) const = 0;
             /*!
                 ensures
@@ -152,7 +152,7 @@ namespace dlib
                         - #at_start() == true
             !*/
 
-            virtual unsigned long size (
+            virtual size_t size (
             ) const = 0;
             /*!
                 ensures

dlib/lzp_buffer/lzp_buffer_kernel_1.h

@@ -63,7 +63,7 @@ namespace dlib
             unsigned long& index
         );
 
-        inline unsigned long size (
+        inline size_t size (
         ) const;
 
         inline unsigned char operator[] (
@@ -208,7 +208,7 @@ namespace dlib
     template <
         typename sbuf
         >
-    unsigned long lzp_buffer_kernel_1<sbuf>::
+    size_t lzp_buffer_kernel_1<sbuf>::
     size (
     ) const 
     { 

dlib/lzp_buffer/lzp_buffer_kernel_2.h

@@ -63,7 +63,7 @@ namespace dlib
             unsigned long& index
         );
 
-        inline unsigned long size (
+        inline size_t size (
         ) const;
 
         inline unsigned char operator[] (
@@ -291,7 +291,7 @@ namespace dlib
     template <
         typename sbuf
         >
-    unsigned long lzp_buffer_kernel_2<sbuf>::
+    size_t lzp_buffer_kernel_2<sbuf>::
     size (
     ) const 
     {