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Diffstat (limited to 'boost/fusion/container/map/detail/value_at_key_impl.hpp')
-rw-r--r-- | boost/fusion/container/map/detail/value_at_key_impl.hpp | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/boost/fusion/container/map/detail/value_at_key_impl.hpp b/boost/fusion/container/map/detail/value_at_key_impl.hpp new file mode 100644 index 0000000000..00a54c4e2d --- /dev/null +++ b/boost/fusion/container/map/detail/value_at_key_impl.hpp @@ -0,0 +1,39 @@ +/*============================================================================= + Copyright (c) 2001-2013 Joel de Guzman + + Distributed under 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_MAP_DETAIL_VALUE_AT_KEY_IMPL_02042013_0821) +#define BOOST_FUSION_MAP_DETAIL_VALUE_AT_KEY_IMPL_02042013_0821 + +#include <boost/fusion/support/config.hpp> +#include <boost/fusion/support/detail/access.hpp> +#include <boost/type_traits/is_const.hpp> +#include <boost/mpl/at.hpp> +#include <boost/mpl/identity.hpp> + +namespace boost { namespace fusion +{ + struct map_tag; + + namespace extension + { + template <typename Tag> + struct value_at_key_impl; + + template <> + struct value_at_key_impl<map_tag> + { + template <typename Sequence, typename Key> + struct apply + { + typedef + decltype(std::declval<Sequence>().get_val(mpl::identity<Key>())) + type; + }; + }; + } +}} + +#endif |