1 files changed, 55 insertions, 0 deletions
diff --git a/boost/gil/extension/io/png/detail/is_allowed.hpp b/boost/gil/extension/io/png/detail/is_allowed.hpp
new file mode 100644
index 0000000000..cf83dd5f02
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+++ b/boost/gil/extension/io/png/detail/is_allowed.hpp
@@ -0,0 +1,55 @@
+/*
+    Copyright 2008 Christian Henning, Lubomir Bourdev
+    Use, modification and distribution are subject to the Boost Software License,
+    Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+    http://www.boost.org/LICENSE_1_0.txt).
+*/
+
+/*************************************************************************************************/
+
+#ifndef BOOST_GIL_EXTENSION_IO_PNG_DETAIL_IS_ALLOWED_HPP
+#define BOOST_GIL_EXTENSION_IO_PNG_DETAIL_IS_ALLOWED_HPP
+
+////////////////////////////////////////////////////////////////////////////////////////
+/// \file
+/// \brief
+/// \author Christian Henning \n
+///
+/// \date 2008 \n
+///
+////////////////////////////////////////////////////////////////////////////////////////
+
+#include <boost/mpl/for_each.hpp>
+
+namespace boost { namespace gil { namespace detail {
+
+template< typename View >
+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;
+
+    typedef typename channel_traits< 
+                typename element_type< pixel_t >::type >::value_type channel_t;
+
+    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;
+
+    return   dst_num_channels == info._num_channels
+          && dst_bit_depth    == info._bit_depth;
+}
+
+template< typename View >
+bool is_allowed( const image_read_info< png_tag >& /* info */
+               , mpl::false_  // is read_and_convert
+               )
+{
+    return true;
+}
+
+} // namespace detail
+} // namespace gil
+} // namespace boost
+
+#endif