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 (

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 
     { 

dlib/lzp_buffer/lzp_buffer_kernel_abstract.h

@@ -100,7 +100,7 @@ namespace dlib
                     until clear() is called and succeeds            
         !*/
 
-        unsigned long size (
+        size_t size (
         ) const;
         /*!
             ensures

dlib/manifold_regularization/linear_manifold_regularizer.h

@@ -40,7 +40,7 @@ namespace dlib
 
             typedef std::vector<neighbor>::const_iterator const_iterator;
 
-            unsigned long size (
+            size_t size (
             ) const
             /*!
                 ensures

dlib/map/map_kernel_1.h

@@ -91,7 +91,7 @@ namespace dlib
             );
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             inline bool at_start (
@@ -311,7 +311,7 @@ namespace dlib
         typename bst_base,
         typename mem_manager
         >
-    unsigned long map_kernel_1<domain,range,bst_base,mem_manager>::
+    size_t map_kernel_1<domain,range,bst_base,mem_manager>::
     size (
     ) const
     {

dlib/opencv/cv_image.h

@@ -50,7 +50,7 @@ namespace dlib
 
         cv_image() : _data(0), _widthStep(0), _nr(0), _nc(0) {}
 
-        unsigned long size () const { return static_cast<unsigned long>(_nr*_nc); }
+        size_t size () const { return static_cast<size_t>(_nr*_nc); }
 
         inline pixel_type* operator[](const long row ) 
         { 

dlib/opencv/cv_image_abstract.h

@@ -127,7 +127,7 @@ namespace dlib
                 - returns the number of columns in this image
         !*/
 
-        unsigned long size (
+        size_t size (
         ) const; 
         /*!
             ensures

dlib/pipe/pipe_kernel_1.h

@@ -66,7 +66,7 @@ namespace dlib
         typedef T type;
 
         explicit pipe (  
-            unsigned long maximum_size
+            size_t maximum_size
         );
 
         virtual ~pipe (
@@ -109,10 +109,10 @@ namespace dlib
         bool is_enabled (
         ) const;
 
-        unsigned long max_size (
+        size_t max_size (
         ) const;
 
-        unsigned long size (
+        size_t size (
         ) const;
 
         bool enqueue (
@@ -144,14 +144,14 @@ namespace dlib
 
     private:
 
-        unsigned long pipe_size;
-        const unsigned long pipe_max_size;
+        size_t pipe_size;
+        const size_t pipe_max_size;
         bool enabled;
 
         T* const data;
 
-        unsigned long first;
-        unsigned long last;
+        size_t first;
+        size_t last;
 
         mutex m;
         signaler dequeue_sig;
@@ -181,7 +181,7 @@ namespace dlib
         >
     pipe<T>::
     pipe (  
-        unsigned long maximum_size
+        size_t maximum_size
     ) : 
         pipe_size(0),
         pipe_max_size(maximum_size),
@@ -313,7 +313,7 @@ namespace dlib
     template <
         typename T
         >
-    unsigned long pipe<T>::
+    size_t pipe<T>::
     max_size (
     ) const
     {
@@ -326,7 +326,7 @@ namespace dlib
     template <
         typename T
         >
-    unsigned long pipe<T>::
+    size_t pipe<T>::
     size (
     ) const
     {

dlib/pipe/pipe_kernel_abstract.h

@@ -38,7 +38,7 @@ namespace dlib
         typedef T type;
 
         explicit pipe (  
-            unsigned long maximum_size
+            size_t maximum_size
         );
         /*!
             ensures                
@@ -175,7 +175,7 @@ namespace dlib
                 - #is_dequeue_enabled() == true
         !*/
 
-        unsigned long max_size (
+        size_t max_size (
         ) const;
         /*!
             ensures
@@ -183,7 +183,7 @@ namespace dlib
                   pipe can contain.
         !*/
 
-        unsigned long size (
+        size_t size (
         ) const;
         /*!
             ensures

dlib/queue/queue_kernel_1.h

@@ -103,7 +103,7 @@ namespace dlib
             );
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             inline bool at_start (
@@ -402,7 +402,7 @@ namespace dlib
         typename T,
         typename mem_manager
         >
-    unsigned long queue_kernel_1<T,mem_manager>::
+    size_t queue_kernel_1<T,mem_manager>::
     size (
     ) const
     {

dlib/queue/queue_kernel_2.h

@@ -112,7 +112,7 @@ namespace dlib
             );
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             inline bool at_start (
@@ -155,13 +155,13 @@ namespace dlib
 
             node* in;
             node* out;
-            unsigned long queue_size;
-            unsigned long in_pos;
-            unsigned long out_pos;
+            size_t queue_size;
+            size_t in_pos;
+            size_t out_pos;
 
 
             mutable node* current_element;
-            mutable unsigned long current_element_pos;
+            mutable size_t current_element_pos;
             mutable bool at_start_;
 
             // restricted functions
@@ -419,7 +419,7 @@ namespace dlib
         unsigned long block_size,
         typename mem_manager
         >
-    unsigned long queue_kernel_2<T,block_size,mem_manager>::
+    size_t queue_kernel_2<T,block_size,mem_manager>::
     size (
     ) const
     {

dlib/sequence/sequence_kernel_1.h

@@ -144,7 +144,7 @@ namespace dlib
             );
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             bool at_start (
@@ -446,7 +446,7 @@ namespace dlib
         typename T,
         typename mem_manager
         >
-    unsigned long sequence_kernel_1<T,mem_manager>::
+    size_t sequence_kernel_1<T,mem_manager>::
     size (
     ) const
     {

dlib/sequence/sequence_kernel_2.h

@@ -103,7 +103,7 @@ namespace dlib
             );
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             bool at_start (
@@ -430,7 +430,7 @@ namespace dlib
         typename T,
         typename mem_manager
         >
-    unsigned long sequence_kernel_2<T,mem_manager>::
+    size_t sequence_kernel_2<T,mem_manager>::
     size (
     ) const
     {

dlib/set/set_kernel_1.h

@@ -80,7 +80,7 @@ namespace dlib
             );
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             inline bool at_start (
@@ -254,7 +254,7 @@ namespace dlib
         typename bst_base,
         typename mem_manager
         >
-    unsigned long set_kernel_1<T,bst_base,mem_manager>::
+    size_t set_kernel_1<T,bst_base,mem_manager>::
     size (
     ) const
     {

dlib/sliding_buffer/sliding_buffer_kernel_1.h

@@ -82,7 +82,7 @@ namespace dlib
             catch (...) { buffer = 0; buffer_size = 0; throw; }
         }
 
-        unsigned long size (
+        size_t size (
         ) const { return buffer_size; }
 
         void rotate_left (

dlib/stack/stack_kernel_1.h

@@ -97,7 +97,7 @@ namespace dlib
             ); 
 
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             inline bool at_start (
@@ -365,7 +365,7 @@ namespace dlib
         typename T,
         typename mem_manager
         >
-    unsigned long stack_kernel_1<T,mem_manager>::
+    size_t stack_kernel_1<T,mem_manager>::
     size (
     ) const
     {

dlib/static_map/static_map_kernel_1.h

@@ -157,7 +157,7 @@ namespace dlib
             );
     
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             inline bool at_start (
@@ -433,7 +433,7 @@ namespace dlib
         typename range,
         typename compare
         >
-    unsigned long static_map_kernel_1<domain,range,compare>::
+    size_t static_map_kernel_1<domain,range,compare>::
     size (
     ) const
     {

dlib/static_set/static_set_kernel_1.h

@@ -52,11 +52,11 @@ namespace dlib
             try
             {
                 item.clear();
-                unsigned long size;
+                size_t size;
                 deserialize(size,in);
                 item.set_size = size;
                 item.d = new T[size];
-                for (unsigned long i = 0; i < size; ++i)
+                for (size_t i = 0; i < size; ++i)
                 {
                     deserialize(item.d[i],in);
                 }
@@ -116,7 +116,7 @@ namespace dlib
             );
     
             // functions from the enumerable interface
-            inline unsigned long size (
+            inline size_t size (
             ) const;
 
             inline bool at_start (
@@ -142,7 +142,7 @@ namespace dlib
 
    
             // data members
-            unsigned long set_size;
+            size_t set_size;
             T* d;
             mutable T* cur;
             mutable bool at_start_;
@@ -231,7 +231,7 @@ namespace dlib
 
             set_size = source.size();
 
-            for (unsigned long i = 0; source.size() > 0; ++i)
+            for (size_t i = 0; source.size() > 0; ++i)
                 source.remove_any(d[i]);
             
             compare comp;
@@ -261,7 +261,7 @@ namespace dlib
 
             set_size = source.size();
 
-            for (unsigned long i = 0; source.size() > 0; ++i)
+            for (size_t i = 0; source.size() > 0; ++i)
                 source.remove_any(d[i]);
         }
         else
@@ -282,10 +282,10 @@ namespace dlib
         const T& item
     ) const
     {
-        unsigned long high = set_size;
-        unsigned long low = 0;
-        unsigned long p = set_size;
-        unsigned long idx;
+        size_t high = set_size;
+        size_t low = 0;
+        size_t p = set_size;
+        size_t idx;
         while (p > 0)
         {
             p = (high-low)>>1;
@@ -306,7 +306,7 @@ namespace dlib
         typename T,
         typename compare
         >
-    unsigned long static_set_kernel_1<T,compare>::
+    size_t static_set_kernel_1<T,compare>::
     size (
     ) const
     {
@@ -421,7 +421,7 @@ namespace dlib
         else if (cur != 0)
         {
             ++cur;
-            if (static_cast<unsigned long>(cur - d) < set_size)
+            if (static_cast<size_t>(cur - d) < set_size)
             {
                 return true;
             }

dlib/statistics/random_subset_selector.h

@@ -67,7 +67,7 @@ namespace dlib
         const std::vector<T>& to_std_vector(
         ) const { return items; }
 
-        unsigned long size (
+        size_t size (
         ) const 
         {
             return items.size();

dlib/statistics/random_subset_selector_abstract.h

@@ -101,7 +101,7 @@ namespace dlib
                 - #size() == 0
         !*/
 
-        unsigned long size (
+        size_t size (
         ) const;
         /*!
             ensures

dlib/svm/kernel_matrix.h

@@ -65,7 +65,7 @@ namespace dlib
         }
 
         template <typename kernel_type>
-        inline unsigned long size ( 
+        inline size_t size (
             const typename kernel_type::sample_type&  
         )
         {

dlib/svm/linearly_independent_subset_finder.h

@@ -296,7 +296,7 @@ namespace dlib
             temp.swap(item.temp);
         }
 
-        unsigned long size (
+        size_t size (
         ) const { return dictionary.size(); }
 
         const matrix<sample_type,0,1,mem_manager_type> get_dictionary (

dlib/svm/linearly_independent_subset_finder_abstract.h

@@ -173,7 +173,7 @@ namespace dlib
                 - swaps *this with item
         !*/
 
-        unsigned long size (
+        size_t size (
         ) const;
         /*!
             ensures

dlib/test/object_detector.cpp

@@ -151,7 +151,7 @@ namespace
             }
         }
 
-        inline unsigned long size () const { return feat_image.size(); }
+        inline size_t size () const { return feat_image.size(); }
         inline long nr () const { return feat_image.nr(); }
         inline long nc () const { return feat_image.nc(); }
 

dlib/xml_parser/xml_parser_kernel_1.h

@@ -127,7 +127,7 @@ namespace dlib
                 bool move_next (
                 ) const { return list.move_next(); }
 
-                unsigned long size (
+                size_t size (
                 ) const { return list.size(); }
             };
 

examples/object_detector_advanced_ex.cpp

@@ -134,7 +134,7 @@ public:
         }
     }
 
-    inline unsigned long size () const { return feat_image.size(); }
+    inline size_t size () const { return feat_image.size(); }
     inline long nr () const { return feat_image.nr(); }
     inline long nc () const { return feat_image.nc(); }