forked from boostorg/fusion
57 lines
1.6 KiB
C++
57 lines
1.6 KiB
C++
|
/*=============================================================================
|
||
|
|
Copyright (c) 2001-2006 Joel de Guzman
|
||
|
|
Copyright (c) 2006 Dan Marsden
|
||
|
|
|
||
|
|
Use, modification and distribution is 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)
|
||
|
|
==============================================================================*/
|
||
|
|
#if !defined(BOOST_FUSION_AT_KEY_20060304_1755)
|
||
|
|
#define BOOST_FUSION_AT_KEY_20060304_1755
|
||
|
|
|
||
|
|
#include <boost/type_traits/is_const.hpp>
|
||
|
|
#include <boost/fusion/support/tag_of.hpp>
|
||
|
|
#include <boost/fusion/support/detail/access.hpp>
|
||
|
|
|
||
|
|
namespace boost { namespace fusion
|
||
|
|
{
|
||
|
|
namespace extension
|
||
|
|
{
|
||
|
|
template <typename Tag>
|
||
|
|
struct at_key_impl
|
||
|
|
{
|
||
|
|
template <typename Sequence, typename Key>
|
||
|
|
struct apply;
|
||
|
|
};
|
||
|
|
}
|
||
|
|
|
||
|
|
namespace result_of
|
||
|
|
{
|
||
|
|
template <typename Sequence, typename Key>
|
||
|
|
struct at_key
|
||
|
|
: extension::at_key_impl<typename detail::tag_of<Sequence>::type>::
|
||
|
|
template apply<Sequence, Key>
|
||
|
|
{};
|
||
|
|
}
|
||
|
|
|
||
|
|
template <typename Key, typename Sequence>
|
||
|
|
inline typename
|
||
|
|
lazy_disable_if<
|
||
|
|
is_const<Sequence>
|
||
|
|
, result_of::at_key<Sequence, Key>
|
||
|
|
>::type
|
||
|
|
at_key(Sequence& seq)
|
||
|
|
{
|
||
|
|
return result_of::at_key<Sequence, Key>::call(seq);
|
||
|
|
}
|
||
|
|
|
||
|
|
template <typename Key, typename Sequence>
|
||
|
|
inline typename result_of::at_key<Sequence const, Key>::type
|
||
|
|
at_key(Sequence const& seq)
|
||
|
|
{
|
||
|
|
return result_of::at_key<Sequence const, Key>::call(seq);
|
||
|
|
}
|
||
|
|
}}
|
||
|
|
|
||
|
|
#endif
|