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- // Copyright David Abrahams 2005. 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)
- #ifndef BOOST_PARAMETER_BINDING_DWA200558_HPP
- # define BOOST_PARAMETER_BINDING_DWA200558_HPP
- # include <boost/mpl/apply.hpp>
- # include <boost/mpl/assert.hpp>
- # include <boost/mpl/and.hpp>
- # include <boost/parameter/aux_/result_of0.hpp>
- # include <boost/parameter/aux_/void.hpp>
- # include <boost/type_traits/is_same.hpp>
- # if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
- # include <boost/mpl/eval_if.hpp>
- # endif
- namespace boost { namespace parameter {
- // A metafunction that, given an argument pack, returns the type of
- // the parameter identified by the given keyword. If no such
- // parameter has been specified, returns Default
- # if BOOST_WORKAROUND(BOOST_MSVC, <= 1300) \
- || BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
- template <class Parameters, class Keyword, class Default>
- struct binding0
- {
- typedef typename mpl::apply_wrap3<
- typename Parameters::binding,Keyword,Default,mpl::true_
- >::type type;
- BOOST_MPL_ASSERT_NOT((
- mpl::and_<
- is_same<Default, void_>
- , is_same<type, void_>
- >
- ));
- };
- # endif
- template <class Parameters, class Keyword, class Default = void_>
- # if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
- struct binding
- # else
- struct binding_eti
- # endif
- {
- # if BOOST_WORKAROUND(BOOST_MSVC, <= 1300) \
- || BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
- typedef typename mpl::eval_if<
- mpl::is_placeholder<Parameters>
- , mpl::identity<int>
- , binding0<Parameters,Keyword,Default>
- >::type type;
- # else
- typedef typename mpl::apply_wrap3<
- typename Parameters::binding,Keyword,Default,mpl::true_
- >::type type;
- BOOST_MPL_ASSERT_NOT((
- mpl::and_<
- is_same<Default, void_>
- , is_same<type, void_>
- >
- ));
- # endif
- # if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
- BOOST_MPL_AUX_LAMBDA_SUPPORT(3,binding,(Parameters,Keyword,Default))
- # endif
- };
- # if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
- template <class Parameters, class Keyword, class Default = void_>
- struct binding
- {
- typedef typename mpl::eval_if<
- is_same<Parameters, int>
- , mpl::identity<int>
- , binding_eti<Parameters, Keyword, Default>
- >::type type;
- BOOST_MPL_AUX_LAMBDA_SUPPORT(3,binding,(Parameters,Keyword,Default))
- };
- # endif
- // A metafunction that, given an argument pack, returns the type of
- // the parameter identified by the given keyword. If no such
- // parameter has been specified, returns the type returned by invoking
- // DefaultFn
- template <class Parameters, class Keyword, class DefaultFn>
- struct lazy_binding
- {
- typedef typename mpl::apply_wrap3<
- typename Parameters::binding
- , Keyword
- , typename aux::result_of0<DefaultFn>::type
- , mpl::true_
- >::type type;
- };
- }} // namespace boost::parameter
- #endif // BOOST_PARAMETER_BINDING_DWA200558_HPP
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