gil/io/get_read_device.hpp

0001 //
0002 // Copyright 2012 Christian Henning
0003 //
0004 // Distributed under the Boost Software License, Version 1.0
0005 // See accompanying file LICENSE_1_0.txt or copy at
0006 // http://www.boost.org/LICENSE_1_0.txt
0007 //
0008 #ifndef BOOST_GIL_IO_GET_READ_DEVICE_HPP
0009 #define BOOST_GIL_IO_GET_READ_DEVICE_HPP
0010
0011 #include <boost/gil/detail/mp11.hpp>
0012 #include <boost/gil/io/device.hpp>
0013 #include <boost/gil/io/path_spec.hpp>
0014
0015 #include <type_traits>
0016
0017 namespace boost { namespace gil {
0018
0019 template< typename T
0020         , typename FormatTag
0021         , class Enable = void
0022         >
0023 struct get_read_device
0024 {};
0025
0026 template <typename Device, typename FormatTag>
0027 struct get_read_device
0028 <
0029     Device,
0030     FormatTag,
0031     typename std::enable_if
0032     <
0033         mp11::mp_and
0034         <
0035             detail::is_adaptable_input_device<FormatTag, Device>,
0036             is_format_tag<FormatTag>
0037         >::value
0038     >::type
0039 >
0040 {
0041     using type = typename detail::is_adaptable_input_device
0042         <
0043             FormatTag,
0044             Device
0045         >::device_type;
0046 };
0047
0048 template <typename String, typename FormatTag>
0049 struct get_read_device
0050 <
0051     String,
0052     FormatTag,
0053     typename std::enable_if
0054     <
0055         mp11::mp_and
0056         <
0057             detail::is_supported_path_spec<String>,
0058             is_format_tag<FormatTag>
0059         >::value
0060     >::type
0061 >
0062 {
0063     using type = detail::file_stream_device<FormatTag>;
0064 };
0065
0066 } // namespace gil
0067 } // namespace boost
0068
0069 #endif