Imported Upstream version 1.70.0upstream/1.70.0

8 files changed, 142 insertions, 133 deletions

diff --git a/boost/gil/extension/io/png/detail/base.hpp b/boost/gil/extension/io/png/detail/base.hpp
index 7feb6f8f09..7af4ef1f22 100644
--- a/boost/gil/extension/io/png/detail/base.hpp
+++ b/boost/gil/extension/io/png/detail/base.hpp
@@ -10,6 +10,8 @@
 
 #include <boost/gil/extension/io/png/tags.hpp>
 
+#include <boost/assert.hpp>
+
 #include <memory>
 
 namespace boost { namespace gil { namespace detail {
@@ -17,8 +19,8 @@ namespace boost { namespace gil { namespace detail {
 struct png_ptr_wrapper
 {
     png_ptr_wrapper()
-    : _struct( NULL )
-    , _info  ( NULL )
+    : _struct( nullptr )
+    , _info  ( nullptr )
     {}
 
     png_structp _struct;
@@ -46,13 +48,13 @@ protected:
     {}
 
     png_ptr_wrapper*       get()       { return _png_ptr.get(); }
-    const png_ptr_wrapper* get() const { return _png_ptr.get(); }
+    png_ptr_wrapper const* get() const { return _png_ptr.get(); }
 
-    png_structp       get_struct()       { return get()->_struct; }
-    const png_structp get_struct() const { return get()->_struct; }
+    png_struct*       get_struct()       { return get()->_struct; }
+    png_struct const* get_struct() const { return get()->_struct; }
 
-    png_infop       get_info()       { return get()->_info; }
-    const png_infop get_info() const { return get()->_info; }
+    png_info*       get_info()       { return get()->_info; }
+    png_info const* get_info() const { return get()->_info; }
 
 private:
 
@@ -60,15 +62,15 @@ private:
     {
         if( png_ptr )
         {
-            assert( png_ptr->_struct && png_ptr->_info );
+            BOOST_ASSERT(png_ptr->_struct && png_ptr->_info);
 
             png_destroy_read_struct( &png_ptr->_struct
                                    , &png_ptr->_info
-                                   , NULL
+                                   , nullptr
                                    );
 
             delete png_ptr;
-            png_ptr = NULL;
+            png_ptr = nullptr;
         }
     }
 
@@ -76,14 +78,14 @@ private:
     {
         if( png_ptr )
         {
-            assert( png_ptr->_struct && png_ptr->_info );
+            BOOST_ASSERT(png_ptr->_struct && png_ptr->_info);
 
             png_destroy_write_struct( &png_ptr->_struct
                                     , &png_ptr->_info
                                     );
 
             delete png_ptr;
-            png_ptr = NULL;
+            png_ptr = nullptr;
         }
     }
 
diff --git a/boost/gil/extension/io/png/detail/is_allowed.hpp b/boost/gil/extension/io/png/detail/is_allowed.hpp
index ac1f9c1749..3fe8386bb6 100644
--- a/boost/gil/extension/io/png/detail/is_allowed.hpp
+++ b/boost/gil/extension/io/png/detail/is_allowed.hpp
@@ -8,6 +8,8 @@
 #ifndef BOOST_GIL_EXTENSION_IO_PNG_DETAIL_IS_ALLOWED_HPP
 #define BOOST_GIL_EXTENSION_IO_PNG_DETAIL_IS_ALLOWED_HPP
 
+#include <boost/gil/extension/io/png/tags.hpp>
+
 #include <boost/mpl/bool_fwd.hpp>
 #include <boost/mpl/for_each.hpp>
 
@@ -18,10 +20,9 @@ bool is_allowed( const image_read_info< png_tag >& info
                , mpl::true_   // is read_and_no_convert
                )
 {
-    typedef typename get_pixel_type< View >::type pixel_t;
+    using pixel_t = typename get_pixel_type<View>::type;
 
-    typedef typename channel_traits<
-                typename element_type< pixel_t >::type >::value_type channel_t;
+    using channel_t = typename channel_traits<typename element_type<pixel_t>::type>::value_type;
 
     const png_num_channels::type dst_num_channels = num_channels< pixel_t >::value;
     const png_bitdepth::type     dst_bit_depth    = detail::unsigned_integral_num_bits< channel_t >::value;
diff --git a/boost/gil/extension/io/png/detail/read.hpp b/boost/gil/extension/io/png/detail/read.hpp
index f14e32a1cf..148f023fb1 100644
--- a/boost/gil/extension/io/png/detail/read.hpp
+++ b/boost/gil/extension/io/png/detail/read.hpp
@@ -16,6 +16,7 @@
 #include <boost/gil/io/base.hpp>
 #include <boost/gil/io/conversion_policies.hpp>
 #include <boost/gil/io/device.hpp>
+#include <boost/gil/io/dynamic_io_new.hpp>
 #include <boost/gil/io/reader_base.hpp>
 #include <boost/gil/io/row_buffer_helper.hpp>
 #include <boost/gil/io/typedefs.hpp>
@@ -45,16 +46,12 @@ class reader< Device
 {
 private:
 
-    typedef reader< Device
-                  , png_tag
-                  , ConversionPolicy
-                  > this_t;
-
-    typedef typename ConversionPolicy::color_converter_type cc_t;
+    using this_t = reader<Device, png_tag, ConversionPolicy>;
+    using cc_t = typename ConversionPolicy::color_converter_type;
 
 public:
 
-    typedef reader_backend< Device, png_tag > backend_t;
+    using backend_t = reader_backend<Device, png_tag>;
 
 public:
 
@@ -220,7 +217,7 @@ public:
 
         // read rest of file, and get additional chunks in info_ptr
         png_read_end( this->get_struct()
-                    , NULL
+                    , nullptr
                     );
     }
 
@@ -231,13 +228,15 @@ private:
             >
     void read_rows( const View& view )
     {
-        typedef detail::row_buffer_helper_view< ImagePixel > row_buffer_helper_t;
+        using row_buffer_helper_t = detail::row_buffer_helper_view<ImagePixel>;
 
-        typedef typename row_buffer_helper_t::iterator_t it_t;
+        using it_t = typename row_buffer_helper_t::iterator_t;
 
-        typedef typename is_same< ConversionPolicy
-                                , detail::read_and_no_convert
-                                >::type is_read_and_convert_t;
+        using is_read_and_convert_t = typename is_same
+            <
+                ConversionPolicy,
+                detail::read_and_no_convert
+            >::type;
 
         io_error_if( !detail::is_allowed< View >( this->_info
                                                 , is_read_and_convert_t()
@@ -265,7 +264,7 @@ private:
                     // Read the image using the "sparkle" effect.
                     png_read_rows( this->get_struct()
                                  , &row_ptr
-                                 , NULL
+                                 , nullptr
                                  , 1
                                  );
                 }
@@ -278,7 +277,7 @@ private:
                     // Read the image using the "sparkle" effect.
                     png_read_rows( this->get_struct()
                                  , &row_ptr
-                                 , NULL
+                                 , nullptr
                                  , 1
                                  );
 
@@ -302,7 +301,7 @@ private:
                     // Read the image using the "sparkle" effect.
                     png_read_rows( this->get_struct()
                                  , &row_ptr
-                                 , NULL
+                                 , nullptr
                                  , 1
                                  );
                 }
@@ -314,7 +313,7 @@ private:
                     // Read the image using the "sparkle" effect.
                     png_read_rows( this->get_struct()
                                  , &row_ptr
-                                 , NULL
+                                 , nullptr
                                  , 1
                                  );
                 }
@@ -337,9 +336,11 @@ struct png_type_format_checker
     template< typename Image >
     bool apply()
     {
-        typedef is_read_supported< typename get_pixel_type< typename Image::view_t >::type
-                                 , png_tag
-                                 > is_supported_t;
+        using is_supported_t = is_read_supported
+            <
+                typename get_pixel_type<typename Image::view_t>::type,
+                png_tag
+            >;
 
         return is_supported_t::_bit_depth  == _bit_depth
             && is_supported_t::_color_type == _color_type;
@@ -376,10 +377,12 @@ class dynamic_image_reader< Device
                    , detail::read_and_no_convert
                    >
 {
-    typedef reader< Device
-                  , png_tag
-                  , detail::read_and_no_convert
-                  > parent_t;
+    using parent_t = reader
+        <
+            Device,
+            png_tag,
+            detail::read_and_no_convert
+        >;
 
 public:
 
diff --git a/boost/gil/extension/io/png/detail/reader_backend.hpp b/boost/gil/extension/io/png/detail/reader_backend.hpp
index 18085b8746..aaf5843ef0 100644
--- a/boost/gil/extension/io/png/detail/reader_backend.hpp
+++ b/boost/gil/extension/io/png/detail/reader_backend.hpp
@@ -31,14 +31,8 @@ struct reader_backend< Device
 {
 public:
 
-    typedef png_tag format_tag_t;
-
-public:
-
-    typedef reader_backend< Device
-                          , png_tag
-                          > this_t;
-
+    using format_tag_t = png_tag;
+    using this_t = reader_backend<Device, png_tag>;
 
 public:
 
@@ -92,12 +86,12 @@ public:
         // the compiler header file version, so that we know if the application
         // was compiled with a compatible version of the library.  REQUIRED
         get()->_struct = png_create_read_struct( PNG_LIBPNG_VER_STRING
-                                             , NULL  // user_error_ptr
-                                             , NULL  // user_error_fn
-                                             , NULL  // user_warning_fn
+                                             , nullptr  // user_error_ptr
+                                             , nullptr  // user_error_fn
+                                             , nullptr  // user_warning_fn
                                              );
 
-        io_error_if( get()->_struct == NULL
+        io_error_if( get()->_struct == nullptr
                    , "png_reader: fail to call png_create_write_struct()"
                    );
 
@@ -114,11 +108,11 @@ public:
         // Allocate/initialize the memory for image information.  REQUIRED.
         get()->_info = png_create_info_struct( get_struct() );
 
-        if( get_info() == NULL )
+        if( get_info() == nullptr )
         {
             png_destroy_read_struct( &get()->_struct
-                                   , NULL
-                                   , NULL
+                                   , nullptr
+                                   , nullptr
                                    );
 
             io_error( "png_reader: fail to call png_create_info_struct()" );
@@ -132,7 +126,7 @@ public:
             //free all of the memory associated with the png_ptr and info_ptr
             png_destroy_read_struct( &get()->_struct
                                    , &get()->_info
-                                   , NULL
+                                   , nullptr
                                    );
 
             io_error( "png is invalid" );
@@ -153,12 +147,12 @@ public:
         // Set up a callback which implements user defined transformation.
         // @todo
         png_set_read_user_transform_fn( get_struct()
-                                      , png_user_transform_ptr( NULL )
+                                      , png_user_transform_ptr( nullptr )
                                       );
 
         png_set_keep_unknown_chunks( get_struct()
                                    , PNG_HANDLE_CHUNK_ALWAYS
-                                   , NULL
+                                   , nullptr
                                    , 0
                                    );
 
@@ -256,8 +250,8 @@ public:
         if( this->_settings._read_icc_profile )
         {
 #if PNG_LIBPNG_VER_MINOR >= 5
-            png_charp icc_name = png_charp( NULL );
-            png_bytep profile  = png_bytep( NULL );
+            png_charp icc_name = png_charp( nullptr );
+            png_bytep profile  = png_bytep( nullptr );
 
             this->_info._valid_icc_profile = png_get_iCCP( get_struct()
                                                          , get_info()
@@ -303,7 +297,7 @@ public:
         // get image palette information from png_info structure
         if( this->_settings._read_palette )
         {
-            png_colorp palette = png_colorp( NULL );
+            png_colorp palette = png_colorp( nullptr );
 
             this->_info._valid_palette = png_get_PLTE( get_struct()
                                                      , get_info()
@@ -324,7 +318,7 @@ public:
         // get background color
         if( this->_settings._read_background )
         {
-            png_color_16p background = png_color_16p( NULL );
+            png_color_16p background = png_color_16p( nullptr );
 
             this->_info._valid_background = png_get_bKGD( get_struct()
                                                         , get_info()
@@ -339,7 +333,7 @@ public:
         // get the histogram
         if( this->_settings._read_histogram )
         {
-            png_uint_16p histogram = png_uint_16p( NULL );
+            png_uint_16p histogram = png_uint_16p( nullptr );
 
             this->_info._valid_histogram = png_get_hIST( get_struct()
                                                        , get_info()
@@ -352,7 +346,7 @@ public:
                 // the palette.
                 if( this->_settings._read_palette == false )
                 {
-                    png_colorp palette = png_colorp( NULL );
+                    png_colorp palette = png_colorp( nullptr );
                     png_get_PLTE( get_struct()
                                 , get_info()
                                 , &palette
@@ -382,9 +376,9 @@ public:
         // get pixel calibration settings
         if( this->_settings._read_pixel_calibration )
         {
-            png_charp purpose = png_charp ( NULL );
-            png_charp units   = png_charp ( NULL );
-            png_charpp params = png_charpp( NULL );
+            png_charp purpose = png_charp ( nullptr );
+            png_charp units   = png_charp ( nullptr );
+            png_charpp params = png_charpp( nullptr );
 
             this->_info._valid_pixel_calibration = png_get_pCAL( get_struct()
                                                                , get_info()
@@ -449,7 +443,7 @@ public:
         // get number of significant bits for each color channel
         if( this->_settings._read_number_of_significant_bits )
         {
-            png_color_8p sig_bits = png_color_8p( NULL );
+            png_color_8p sig_bits = png_color_8p( nullptr );
 
             this->_info._valid_significant_bits = png_get_sBIT( get_struct()
                                                               , get_info()
@@ -491,16 +485,13 @@ public:
 #else
         if( this->_settings._read_scale_factors )
         {
-            png_charp scale_width  = NULL;
-            png_charp scale_height = NULL;
+            png_charp scale_width  = nullptr;
+            png_charp scale_height = nullptr;
 
-            if( this->_info._valid_scale_factors = png_get_sCAL_s( get_struct()
-                                                                 , get_info()
-                                                                 , &this->_info._scale_unit
-                                                                 , &scale_width
-                                                                 , &scale_height
-                                                                 ) > 0
-              )
+            this->_info._valid_scale_factors = png_get_sCAL_s(
+                get_struct(), get_info(), &this->_info._scale_unit, &scale_width, &scale_height);
+
+            if (this->_info._valid_scale_factors)
             {
                 if( scale_width )
                 {
@@ -524,7 +515,7 @@ public:
         // get comments information from png_info structure
         if( this->_settings._read_comments )
         {
-            png_textp text = png_textp( NULL );
+            png_textp text = png_textp( nullptr );
 
             this->_info._valid_text = png_get_text( get_struct()
                                                   , get_info()
@@ -556,7 +547,7 @@ public:
         // get last modification time
         if( this->_settings._read_last_modification_time )
         {
-            png_timep mod_time = png_timep( NULL );
+            png_timep mod_time = png_timep( nullptr );
             this->_info._valid_modification_time = png_get_tIME( get_struct()
                                                                , get_info()
                                                                , &mod_time
@@ -570,8 +561,8 @@ public:
         // get transparency data
         if( this->_settings._read_transparency_data )
         {
-            png_bytep     trans        = png_bytep    ( NULL );
-            png_color_16p trans_values = png_color_16p( NULL );
+            png_bytep     trans        = png_bytep    ( nullptr );
+            png_color_16p trans_values = png_color_16p( nullptr );
 
             this->_info._valid_transparency_factors = png_get_tRNS( get_struct()
                                                                   , get_info()
diff --git a/boost/gil/extension/io/png/detail/scanline_read.hpp b/boost/gil/extension/io/png/detail/scanline_read.hpp
index 99374f164a..bb27f85378 100644
--- a/boost/gil/extension/io/png/detail/scanline_read.hpp
+++ b/boost/gil/extension/io/png/detail/scanline_read.hpp
@@ -35,12 +35,10 @@ class scanline_reader< Device
 {
 public:
 
-    typedef png_tag tag_t;
-    typedef reader_backend < Device, tag_t > backend_t;
-    typedef scanline_reader< Device, tag_t > this_t;
-    typedef scanline_read_iterator< this_t > iterator_t;
-
-public:
+    using tag_t = png_tag;
+    using backend_t = reader_backend<Device, tag_t>;
+    using this_t = scanline_reader<Device, tag_t>;
+    using iterator_t = scanline_read_iterator<this_t>;
 
     //
     // Constructor
diff --git a/boost/gil/extension/io/png/detail/supported_types.hpp b/boost/gil/extension/io/png/detail/supported_types.hpp
index ed98917ffc..777d9729a9 100644
--- a/boost/gil/extension/io/png/detail/supported_types.hpp
+++ b/boost/gil/extension/io/png/detail/supported_types.hpp
@@ -8,10 +8,14 @@
 #ifndef BOOST_GIL_EXTENSION_IO_PNG_DETAIL_SUPPORTED_TYPES_HPP
 #define BOOST_GIL_EXTENSION_IO_PNG_DETAIL_SUPPORTED_TYPES_HPP
 
+#include <boost/gil/extension/io/png/tags.hpp>
+
 #ifdef BOOST_GIL_IO_ENABLE_GRAY_ALPHA
 #include <boost/gil/extension/toolbox/color_spaces/gray_alpha.hpp>
 #endif // BOOST_GIL_IO_ENABLE_GRAY_ALPHA
 
+#include <cstddef>
+
 namespace boost { namespace gil { namespace detail {
 
 static const size_t PNG_BYTES_TO_CHECK = 4;
@@ -323,9 +327,11 @@ struct is_read_supported< Pixel
                                           >::is_supported
                 >
 {
-    typedef detail::png_read_support< typename channel_type< Pixel >::type
-                                    , typename color_space_type< Pixel >::type
-                                    > parent_t;
+    using parent_t = detail::png_read_support
+        <
+            typename channel_type<Pixel>::type,
+            typename color_space_type<Pixel>::type
+        >;
 
     static const png_bitdepth::type   _bit_depth  = parent_t::_bit_depth;
     static const png_color_type::type _color_type = parent_t::_color_type;
@@ -340,9 +346,11 @@ struct is_write_supported< Pixel
                                            >::is_supported
                 >
 {
-    typedef detail::png_write_support< typename channel_type< Pixel >::type
-                                     , typename color_space_type< Pixel >::type
-                                     > parent_t;
+    using parent_t = detail::png_write_support
+        <
+            typename channel_type<Pixel>::type,
+            typename color_space_type<Pixel>::type
+        >;
 
     static const png_bitdepth::type   _bit_depth  = parent_t::_bit_depth;
     static const png_color_type::type _color_type = parent_t::_color_type;
diff --git a/boost/gil/extension/io/png/detail/write.hpp b/boost/gil/extension/io/png/detail/write.hpp
index cf1ef2a2a7..9cec03ada5 100644
--- a/boost/gil/extension/io/png/detail/write.hpp
+++ b/boost/gil/extension/io/png/detail/write.hpp
@@ -11,6 +11,7 @@
 #include <boost/gil/extension/io/png/detail/writer_backend.hpp>
 
 #include <boost/gil/io/device.hpp>
+#include <boost/gil/io/dynamic_io_new.hpp>
 #include <boost/gil/io/row_buffer_helper.hpp>
 
 #include <boost/mpl/and.hpp>
@@ -18,6 +19,8 @@
 #include <boost/mpl/less.hpp>
 #include <boost/mpl/not.hpp>
 
+#include <type_traits>
+
 namespace boost { namespace gil {
 
 #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
@@ -53,7 +56,7 @@ class writer< Device
 
 public:
 
-    typedef writer_backend< Device , png_tag > backend_t;
+    using backend_t = writer_backend<Device, png_tag>;
 
     writer( const Device&                      io_dev
           , const image_write_info< png_tag >& info
@@ -85,11 +88,13 @@ private:
                    ,  mpl::false_       // is bit aligned
                    )
     {
-        typedef typename get_pixel_type< View >::type pixel_t;
+        using pixel_t = typename get_pixel_type<View>::type;
 
-        typedef detail::png_write_support< typename channel_type    < pixel_t >::type
-                                         , typename color_space_type< pixel_t >::type
-                                         > png_rw_info;
+        using png_rw_info = detail::png_write_support
+            <
+                typename channel_type<pixel_t>::type,
+                typename color_space_type<pixel_t>::type
+            >;
 
         if( little_endian() )
         {
@@ -123,11 +128,11 @@ private:
                    , mpl::true_         // is bit aligned
                    )
     {
-        typedef detail::png_write_support< typename kth_semantic_element_type< typename View::value_type
-                                                                             , 0
-                                                                             >::type
-                                         , typename color_space_type<View>::type
-                                         > png_rw_info;
+        using png_rw_info = detail::png_write_support
+            <
+                typename kth_semantic_element_type<typename View::value_type, 0>::type,
+                typename color_space_type<View>::type
+            >;
 
         if (little_endian() )
         {
@@ -164,25 +169,30 @@ private:
     template< typename Info > struct is_less_than_eight : mpl::less< mpl::int_< Info::_bit_depth >, mpl::int_< 8 > > {};
     template< typename Info > struct is_equal_to_sixteen : mpl::equal_to< mpl::int_< Info::_bit_depth >, mpl::int_< 16 > > {};
 
-    template< typename Info >
-    void set_swap( typename enable_if< is_less_than_eight< Info > >::type* /* ptr */ = 0 )
+    template <typename Info>
+    void set_swap(typename std::enable_if<is_less_than_eight<Info>::value>::type* /*ptr*/ = 0)
     {
-        png_set_packswap( this->get_struct() );
+        png_set_packswap(this->get_struct());
     }
 
-    template< typename Info >
-    void set_swap( typename enable_if< is_equal_to_sixteen< Info > >::type* /* ptr */ = 0 )
+    template <typename Info>
+    void set_swap(typename std::enable_if<is_equal_to_sixteen<Info>::value>::type* /*ptr*/ = 0)
     {
-        png_set_swap( this->get_struct() );
+        png_set_swap(this->get_struct());
     }
 
-    template< typename Info >
-    void set_swap( typename enable_if< mpl::and_< mpl::not_< is_less_than_eight< Info > >
-                                                , mpl::not_< is_equal_to_sixteen< Info > >
-                                                >
-                                     >::type* /* ptr */ = 0
-                 )
-    {}
+    template <typename Info>
+    void set_swap(
+        typename std::enable_if
+        <
+            mpl::and_
+            <
+                mpl::not_<is_less_than_eight<Info>>,
+                mpl::not_<is_equal_to_sixteen<Info>>
+            >::value
+        >::type* /*ptr*/ = nullptr)
+    {
+    }
 };
 
 ///
@@ -196,9 +206,7 @@ class dynamic_image_writer< Device
                    , png_tag
                    >
 {
-    typedef writer< Device
-                  , png_tag
-                  > parent_t;
+    using parent_t = writer<Device, png_tag>;
 
 public:
 
diff --git a/boost/gil/extension/io/png/detail/writer_backend.hpp b/boost/gil/extension/io/png/detail/writer_backend.hpp
index 659be4fa36..dc9068e4dc 100644
--- a/boost/gil/extension/io/png/detail/writer_backend.hpp
+++ b/boost/gil/extension/io/png/detail/writer_backend.hpp
@@ -35,15 +35,11 @@ struct writer_backend< Device
 
 private:
 
-    typedef writer_backend< Device
-                          , png_tag
-                          > this_t;
+    using this_t = writer_backend<Device, png_tag>;
 
 public:
 
-    typedef png_tag format_tag_t;
-
-public:
+    using format_tag_t = png_tag;
 
     ///
     /// Constructor
@@ -61,22 +57,22 @@ public:
         // the library version is compatible with the one used at compile time,
         // in case we are using dynamically linked libraries.  REQUIRED.
         get()->_struct = png_create_write_struct( PNG_LIBPNG_VER_STRING
-                                                , NULL  // user_error_ptr
-                                                , NULL  // user_error_fn
-                                                , NULL  // user_warning_fn
+                                                , nullptr  // user_error_ptr
+                                                , nullptr  // user_error_fn
+                                                , nullptr  // user_warning_fn
                                                 );
 
-        io_error_if( get_struct() == NULL
+        io_error_if( get_struct() == nullptr
                    , "png_writer: fail to call png_create_write_struct()"
                    );
 
         // Allocate/initialize the image information data.  REQUIRED
         get()->_info = png_create_info_struct( get_struct() );
 
-        if( get_info() == NULL )
+        if( get_info() == nullptr )
         {
             png_destroy_write_struct( &get()->_struct
-                                    , NULL
+                                    , nullptr
                                     );
 
             io_error( "png_writer: fail to call png_create_info_struct()" );
@@ -102,9 +98,11 @@ protected:
     template< typename View >
     void write_header( const View& view )
     {
-        typedef detail::png_write_support< typename channel_type< typename get_pixel_type< View >::type >::type
-                                         , typename color_space_type< View >::type
-                                         > png_rw_info_t;
+        using png_rw_info_t = detail::png_write_support
+            <
+                typename channel_type<typename get_pixel_type<View>::type>::type,
+                typename color_space_type<View>::type
+            >;
 
         // Set the image information here.  Width and height are up to 2^31,
         // bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on