ceph/src/boost/boost/gil/extension/io/png/detail/is_allowed.hpp

   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 >
  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 >
  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