/////////////////////////////////////////////////////////////////////////////// | |
/// \file as_expr.hpp | |
/// Contains definition of the as_expr\<\> and as_child\<\> helper class | |
/// templates used to implement proto::domain's as_expr\<\> and as_child\<\> | |
/// member templates. | |
// | |
// Copyright 2010 Eric Niebler. 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_PROTO_DETAIL_AS_EXPR_HPP_EAN_06_09_2010 | |
#define BOOST_PROTO_DETAIL_AS_EXPR_HPP_EAN_06_09_2010 | |
#include <boost/config.hpp> | |
#include <boost/detail/workaround.hpp> | |
#include <boost/type_traits/remove_const.hpp> | |
#include <boost/proto/proto_fwd.hpp> | |
#include <boost/proto/args.hpp> | |
namespace boost { namespace proto { namespace detail | |
{ | |
//////////////////////////////////////////////////////////////////////////////////////////////// | |
template<typename Generator> | |
struct base_generator | |
{ | |
typedef Generator type; | |
}; | |
template<typename Generator> | |
struct base_generator<use_basic_expr<Generator> > | |
{ | |
typedef Generator type; | |
}; | |
//////////////////////////////////////////////////////////////////////////////////////////////// | |
template<typename T, typename Generator, bool WantsBasicExpr> | |
struct as_expr; | |
//////////////////////////////////////////////////////////////////////////////////////////////// | |
template<typename T, typename Generator> | |
struct as_expr<T, Generator, false> | |
{ | |
typedef typename term_traits<T &>::value_type value_type; | |
typedef proto::expr<proto::tag::terminal, term<value_type>, 0> expr_type; | |
typedef typename Generator::template result<Generator(expr_type)>::type result_type; | |
result_type operator()(T &t) const | |
{ | |
return Generator()(expr_type::make(t)); | |
} | |
}; | |
//////////////////////////////////////////////////////////////////////////////////////////////// | |
template<typename T, typename Generator> | |
struct as_expr<T, Generator, true> | |
{ | |
typedef typename term_traits<T &>::value_type value_type; | |
typedef proto::basic_expr<proto::tag::terminal, term<value_type>, 0> expr_type; | |
typedef typename Generator::template result<Generator(expr_type)>::type result_type; | |
result_type operator()(T &t) const | |
{ | |
return Generator()(expr_type::make(t)); | |
} | |
}; | |
//////////////////////////////////////////////////////////////////////////////////////////////// | |
template<typename T> | |
struct as_expr<T, proto::default_generator, false> | |
{ | |
typedef typename term_traits<T &>::value_type value_type; | |
typedef proto::expr<proto::tag::terminal, term<value_type>, 0> result_type; | |
result_type operator()(T &t) const | |
{ | |
return result_type::make(t); | |
} | |
}; | |
//////////////////////////////////////////////////////////////////////////////////////////////// | |
template<typename T> | |
struct as_expr<T, proto::default_generator, true> | |
{ | |
typedef typename term_traits<T &>::value_type value_type; | |
typedef proto::basic_expr<proto::tag::terminal, term<value_type>, 0> result_type; | |
result_type operator()(T &t) const | |
{ | |
return result_type::make(t); | |
} | |
}; | |
//////////////////////////////////////////////////////////////////////////////////////////////// | |
template<typename T, typename Generator, bool WantsBasicExpr> | |
struct as_child; | |
//////////////////////////////////////////////////////////////////////////////////////////////// | |
template<typename T, typename Generator> | |
struct as_child<T, Generator, false> | |
{ | |
#if BOOST_WORKAROUND(BOOST_MSVC, == 1310) | |
typedef typename term_traits<T &>::reference reference; | |
#else | |
typedef T &reference; | |
#endif | |
typedef proto::expr<proto::tag::terminal, term<reference>, 0> expr_type; | |
typedef typename Generator::template result<Generator(expr_type)>::type result_type; | |
result_type operator()(T &t) const | |
{ | |
return Generator()(expr_type::make(t)); | |
} | |
}; | |
//////////////////////////////////////////////////////////////////////////////////////////////// | |
template<typename T, typename Generator> | |
struct as_child<T, Generator, true> | |
{ | |
#if BOOST_WORKAROUND(BOOST_MSVC, == 1310) | |
typedef typename term_traits<T &>::reference reference; | |
#else | |
typedef T &reference; | |
#endif | |
typedef proto::basic_expr<proto::tag::terminal, term<reference>, 0> expr_type; | |
typedef typename Generator::template result<Generator(expr_type)>::type result_type; | |
result_type operator()(T &t) const | |
{ | |
return Generator()(expr_type::make(t)); | |
} | |
}; | |
//////////////////////////////////////////////////////////////////////////////////////////////// | |
template<typename T> | |
struct as_child<T, proto::default_generator, false> | |
{ | |
#if BOOST_WORKAROUND(BOOST_MSVC, == 1310) | |
typedef typename term_traits<T &>::reference reference; | |
#else | |
typedef T &reference; | |
#endif | |
typedef proto::expr<proto::tag::terminal, term<reference>, 0> result_type; | |
result_type operator()(T &t) const | |
{ | |
return result_type::make(t); | |
} | |
}; | |
//////////////////////////////////////////////////////////////////////////////////////////////// | |
template<typename T> | |
struct as_child<T, proto::default_generator, true> | |
{ | |
#if BOOST_WORKAROUND(BOOST_MSVC, == 1310) | |
typedef typename term_traits<T &>::reference reference; | |
#else | |
typedef T &reference; | |
#endif | |
typedef proto::basic_expr<proto::tag::terminal, term<reference>, 0> result_type; | |
result_type operator()(T &t) const | |
{ | |
return result_type::make(t); | |
} | |
}; | |
}}} | |
#endif |