williamr@2: 
williamr@2: #ifndef BOOST_MPL_EVAL_IF_HPP_INCLUDED
williamr@2: #define BOOST_MPL_EVAL_IF_HPP_INCLUDED
williamr@2: 
williamr@2: // Copyright Aleksey Gurtovoy 2000-2004
williamr@2: //
williamr@2: // Distributed under the Boost Software License, Version 1.0. 
williamr@2: // (See accompanying file LICENSE_1_0.txt or copy at 
williamr@2: // http://www.boost.org/LICENSE_1_0.txt)
williamr@2: //
williamr@2: // See http://www.boost.org/libs/mpl for documentation.
williamr@2: 
williamr@2: // $Source: /cvsroot/boost/boost/boost/mpl/eval_if.hpp,v $
williamr@2: // $Date: 2004/11/28 01:54:10 $
williamr@2: // $Revision: 1.3 $
williamr@2: 
williamr@2: #include <boost/mpl/if.hpp>
williamr@2: #include <boost/mpl/aux_/na_spec.hpp>
williamr@2: #include <boost/mpl/aux_/lambda_support.hpp>
williamr@2: #include <boost/mpl/aux_/config/msvc.hpp>
williamr@2: #include <boost/mpl/aux_/config/gcc.hpp>
williamr@2: #include <boost/mpl/aux_/config/workaround.hpp>
williamr@2: 
williamr@2: namespace boost { namespace mpl {
williamr@2: 
williamr@2: template<
williamr@2:       typename BOOST_MPL_AUX_NA_PARAM(C)
williamr@2:     , typename BOOST_MPL_AUX_NA_PARAM(F1)
williamr@2:     , typename BOOST_MPL_AUX_NA_PARAM(F2)
williamr@2:     >
williamr@2: struct eval_if
williamr@2: #if BOOST_WORKAROUND(BOOST_MSVC, <= 1300) \
williamr@2:      || ( BOOST_WORKAROUND(BOOST_MPL_CFG_GCC, >= 0x0300) \
williamr@2:         && BOOST_WORKAROUND(BOOST_MPL_CFG_GCC, BOOST_TESTED_AT(0x0304)) \
williamr@2:         )
williamr@2: {
williamr@2:     typedef typename if_<C,F1,F2>::type f_;
williamr@2:     typedef typename f_::type type;
williamr@2: #else
williamr@2:     : if_<C,F1,F2>::type
williamr@2: {
williamr@2: #endif
williamr@2:     BOOST_MPL_AUX_LAMBDA_SUPPORT(3,eval_if,(C,F1,F2))
williamr@2: };
williamr@2: 
williamr@2: // (almost) copy & paste in order to save one more 
williamr@2: // recursively nested template instantiation to user
williamr@2: template<
williamr@2:       bool C
williamr@2:     , typename F1
williamr@2:     , typename F2
williamr@2:     >
williamr@2: struct eval_if_c
williamr@2: #if BOOST_WORKAROUND(BOOST_MSVC, <= 1300) \
williamr@2:      || ( BOOST_WORKAROUND(BOOST_MPL_CFG_GCC, >= 0x0300) \
williamr@2:         && BOOST_WORKAROUND(BOOST_MPL_CFG_GCC, BOOST_TESTED_AT(0x0304)) \
williamr@2:         )
williamr@2: {
williamr@2:     typedef typename if_c<C,F1,F2>::type f_;
williamr@2:     typedef typename f_::type type;
williamr@2: #else
williamr@2:     : if_c<C,F1,F2>::type
williamr@2: {
williamr@2: #endif
williamr@2: };
williamr@2: 
williamr@2: BOOST_MPL_AUX_NA_SPEC(3, eval_if)
williamr@2: 
williamr@2: }}
williamr@2: 
williamr@2: #endif // BOOST_MPL_EVAL_IF_HPP_INCLUDED