1 //
2 // Copyright 2008 Christian Henning, Lubomir Bourdev
3 //
4 // Distributed under the Boost Software License, Version 1.0
5 // See accompanying file LICENSE_1_0.txt or copy at
6 // http://www.boost.org/LICENSE_1_0.txt
7 //
8 #ifndef BOOST_GIL_EXTENSION_IO_PNG_DETAIL_IS_ALLOWED_HPP
9 #define BOOST_GIL_EXTENSION_IO_PNG_DETAIL_IS_ALLOWED_HPP
10 
11 #include <boost/gil/extension/io/png/tags.hpp>
12 
13 #include <type_traits>
14 
15 namespace boost { namespace gil { namespace detail {
16 
17 template< typename View >
is_allowed(const image_read_info<png_tag> & info,std::true_type)18 bool is_allowed( const image_read_info< png_tag >& info
19                , std::true_type   // is read_and_no_convert
20                )
21 {
22     using pixel_t = typename get_pixel_type<View>::type;
23 
24     using channel_t = typename channel_traits<typename element_type<pixel_t>::type>::value_type;
25 
26     const png_num_channels::type dst_num_channels = num_channels< pixel_t >::value;
27     const png_bitdepth::type     dst_bit_depth    = detail::unsigned_integral_num_bits< channel_t >::value;
28 
29     return   dst_num_channels == info._num_channels
30           && dst_bit_depth    == info._bit_depth;
31 }
32 
33 template< typename View >
is_allowed(const image_read_info<png_tag> &,std::false_type)34 bool is_allowed( const image_read_info< png_tag >& /* info */
35                , std::false_type  // is read_and_convert
36                )
37 {
38     return true;
39 }
40 
41 } // namespace detail
42 } // namespace gil
43 } // namespace boost
44 
45 #endif
46