Chris@16: // Copyright David Abrahams 2005. Distributed under the Boost
Chris@16: // Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: #ifndef BOOST_PARAMETER_BINDING_DWA200558_HPP
Chris@16: # define BOOST_PARAMETER_BINDING_DWA200558_HPP
Chris@16: 
Chris@16: # include <boost/mpl/apply.hpp>
Chris@16: # include <boost/mpl/assert.hpp>
Chris@16: # include <boost/mpl/and.hpp>
Chris@16: # include <boost/parameter/aux_/result_of0.hpp>
Chris@16: # include <boost/parameter/aux_/void.hpp>
Chris@16: # include <boost/type_traits/is_same.hpp>
Chris@16: 
Chris@16: # if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
Chris@16: #  include <boost/mpl/eval_if.hpp>
Chris@16: # endif
Chris@16: 
Chris@16: namespace boost { namespace parameter { 
Chris@16: 
Chris@16: // A metafunction that, given an argument pack, returns the type of
Chris@16: // the parameter identified by the given keyword.  If no such
Chris@16: // parameter has been specified, returns Default
Chris@16: 
Chris@16: # if BOOST_WORKAROUND(BOOST_MSVC, <= 1300) \
Chris@16:   || BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
Chris@16: template <class Parameters, class Keyword, class Default>
Chris@16: struct binding0
Chris@16: {
Chris@16:     typedef typename mpl::apply_wrap3<
Chris@16:         typename Parameters::binding,Keyword,Default,mpl::true_
Chris@16:     >::type type;
Chris@16: 
Chris@16:     BOOST_MPL_ASSERT_NOT((
Chris@16:         mpl::and_<
Chris@16:             is_same<Default, void_>
Chris@16:           , is_same<type, void_>
Chris@16:         >
Chris@16:     ));
Chris@16: };
Chris@16: # endif
Chris@16: 
Chris@16: template <class Parameters, class Keyword, class Default = void_>
Chris@16: # if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
Chris@16: struct binding
Chris@16: # else
Chris@16: struct binding_eti
Chris@16: # endif
Chris@16: {
Chris@16: # if BOOST_WORKAROUND(BOOST_MSVC, <= 1300) \
Chris@16:   || BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
Chris@16:     typedef typename mpl::eval_if<
Chris@16:         mpl::is_placeholder<Parameters>
Chris@16:       , mpl::identity<int>
Chris@16:       , binding0<Parameters,Keyword,Default>
Chris@16:     >::type type;
Chris@16: # else
Chris@16:     typedef typename mpl::apply_wrap3<
Chris@16:         typename Parameters::binding,Keyword,Default,mpl::true_
Chris@16:     >::type type;
Chris@16: 
Chris@16:     BOOST_MPL_ASSERT_NOT((
Chris@16:         mpl::and_<
Chris@16:             is_same<Default, void_>
Chris@16:           , is_same<type, void_>
Chris@16:         >
Chris@16:     ));
Chris@16: # endif
Chris@16: 
Chris@16: # if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
Chris@16:     BOOST_MPL_AUX_LAMBDA_SUPPORT(3,binding,(Parameters,Keyword,Default))
Chris@16: # endif
Chris@16: };
Chris@16: 
Chris@16: # if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
Chris@16: template <class Parameters, class Keyword, class Default = void_>
Chris@16: struct binding
Chris@16: {
Chris@16:     typedef typename mpl::eval_if<
Chris@16:         is_same<Parameters, int>
Chris@16:       , mpl::identity<int>
Chris@16:       , binding_eti<Parameters, Keyword, Default>
Chris@16:     >::type type;
Chris@16: 
Chris@16:     BOOST_MPL_AUX_LAMBDA_SUPPORT(3,binding,(Parameters,Keyword,Default))
Chris@16: };
Chris@16: # endif
Chris@16: 
Chris@16: // A metafunction that, given an argument pack, returns the type of
Chris@16: // the parameter identified by the given keyword.  If no such
Chris@16: // parameter has been specified, returns the type returned by invoking
Chris@16: // DefaultFn
Chris@16: template <class Parameters, class Keyword, class DefaultFn>
Chris@16: struct lazy_binding
Chris@16: {
Chris@16:   typedef typename mpl::apply_wrap3<
Chris@16:       typename Parameters::binding
Chris@16:     , Keyword
Chris@16:     , typename aux::result_of0<DefaultFn>::type
Chris@16:     , mpl::true_
Chris@16:   >::type type;
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: }} // namespace boost::parameter
Chris@16: 
Chris@16: #endif // BOOST_PARAMETER_BINDING_DWA200558_HPP