boost/gil/extension/io/pnm/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_PNM_DETAIL_IS_ALLOWED_HPP
   9 #define BOOST_GIL_EXTENSION_IO_PNM_DETAIL_IS_ALLOWED_HPP
  10
  11 #include <boost/gil/extension/io/pnm/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< pnm_tag >& info
  19                , std::true_type   // is read_and_no_convert
  20                )
  21 {
  22     pnm_image_type::type asc_type = is_read_supported< typename get_pixel_type< View >::type
  23                                                      , pnm_tag
  24                                                      >::_asc_type;
  25
  26     pnm_image_type::type bin_type = is_read_supported< typename get_pixel_type< View >::type
  27                                                      , pnm_tag
  28                                                      >::_bin_type;
  29     if( info._type == pnm_image_type::mono_asc_t::value )
  30     {
  31         // ascii mono images are read gray8_image_t
  32         return (  asc_type == pnm_image_type::gray_asc_t::value );
  33     }
  34
  35
  36     return (  asc_type == info._type
  37            || bin_type == info._type
  38            );
  39 }
  40
  41 template< typename View >
  42 bool is_allowed( const image_read_info< pnm_tag >& /* info */
  43                , std::false_type  // is read_and_convert
  44                )
  45 {
  46     return true;
  47 }
  48
  49 } // namespace detail
  50 } // namespace gil
  51 } // namespace boost
  52
  53 #endif