boost/gil/extension/io/raw/detail/is_allowed.hpp

   1 //
   2 // Copyright 2009 Christian Henning
   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_RAW_DETAIL_IS_ALLOWED_HPP
   9 #define BOOST_GIL_EXTENSION_IO_RAW_DETAIL_IS_ALLOWED_HPP
  10
  11 #include <boost/gil/extension/io/raw/tags.hpp>
  12 #include <boost/gil/io/base.hpp>
  13
  14 #include <type_traits>
  15
  16 namespace boost { namespace gil { namespace detail {
  17
  18 template< typename View >
  19 bool is_allowed( const image_read_info< raw_tag >& info
  20                , std::true_type   // is read_and_no_convert
  21                )
  22 {
  23     using pixel_t = typename get_pixel_type<View>::type;
  24     using num_channel_t = typename num_channels<pixel_t>::value_type;
  25     using channel_t = typename channel_traits<typename element_type<typename View::value_type>::type>::value_type;
  26
  27     constexpr num_channel_t dst_samples_per_pixel = num_channels<pixel_t>::value;
  28     constexpr unsigned int dst_bits_per_pixel = detail::unsigned_integral_num_bits<channel_t>::value;
  29     constexpr bool is_type_signed = std::is_signed<channel_t>::value;
  30
  31     return (dst_samples_per_pixel == info._samples_per_pixel &&
  32             dst_bits_per_pixel == static_cast<unsigned int>(info._bits_per_pixel) &&
  33             !is_type_signed);
  34 }
  35
  36 template< typename View >
  37 bool is_allowed( const image_read_info< raw_tag >& /* info */
  38                , std::false_type  // is read_and_convert
  39                )
  40 {
  41     return true;
  42 }
  43
  44 } // namespace detail
  45 } // namespace gil
  46 } // namespace boost
  47
  48 #endif