Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: /// \file literal.hpp
Chris@16: /// The literal\<\> terminal wrapper, and the proto::lit() function for
Chris@16: /// creating literal\<\> wrappers.
Chris@16: //
Chris@16: //  Copyright 2008 Eric Niebler. Distributed under the Boost
Chris@16: //  Software License, Version 1.0. (See accompanying file
Chris@16: //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_PROTO_LITERAL_HPP_EAN_01_03_2007
Chris@16: #define BOOST_PROTO_LITERAL_HPP_EAN_01_03_2007
Chris@16: 
Chris@16: #include <boost/config.hpp>
Chris@16: #include <boost/proto/proto_fwd.hpp>
Chris@16: #include <boost/proto/expr.hpp>
Chris@16: #include <boost/proto/traits.hpp>
Chris@16: #include <boost/proto/extends.hpp>
Chris@16: 
Chris@16: namespace boost { namespace proto
Chris@16: {
Chris@16:     namespace utility
Chris@16:     {
Chris@16:         /// \brief A simple wrapper for a terminal, provided for
Chris@16:         /// ease of use.
Chris@16:         ///
Chris@16:         /// A simple wrapper for a terminal, provided for
Chris@16:         /// ease of use. In all cases, <tt>literal\<X\> l(x);</tt>
Chris@16:         /// is equivalent to <tt>terminal\<X\>::type l = {x};</tt>.
Chris@16:         ///
Chris@16:         /// The \c Domain template parameter defaults to
Chris@16:         /// \c proto::default_domain.
Chris@16:         template<
Chris@16:             typename T
Chris@16:           , typename Domain // = default_domain
Chris@16:         >
Chris@16:         struct literal
Chris@16:           : extends<basic_expr<tag::terminal, term<T>, 0>, literal<T, Domain>, Domain>
Chris@16:         {
Chris@16:         private:
Chris@16:             typedef basic_expr<tag::terminal, term<T>, 0> terminal_type;
Chris@16:             typedef extends<terminal_type, literal<T, Domain>, Domain> base_type;
Chris@16:             typedef literal<T, Domain> literal_t;
Chris@16: 
Chris@16:         public:
Chris@16:             typedef typename detail::term_traits<T>::value_type       value_type;
Chris@16:             typedef typename detail::term_traits<T>::reference        reference;
Chris@16:             typedef typename detail::term_traits<T>::const_reference  const_reference;
Chris@16: 
Chris@16:             literal()
Chris@16:               : base_type(terminal_type::make(T()))
Chris@16:             {}
Chris@16: 
Chris@16:             template<typename U>
Chris@16:             literal(U &u)
Chris@16:               : base_type(terminal_type::make(u))
Chris@16:             {}
Chris@16: 
Chris@16:             template<typename U>
Chris@16:             literal(U const &u)
Chris@16:               : base_type(terminal_type::make(u))
Chris@16:             {}
Chris@16: 
Chris@16:             template<typename U>
Chris@16:             literal(literal<U, Domain> const &u)
Chris@16:               : base_type(terminal_type::make(u.get()))
Chris@16:             {}
Chris@16: 
Chris@16:             BOOST_PROTO_EXTENDS_USING_ASSIGN(literal_t)
Chris@16: 
Chris@16:             reference get()
Chris@16:             {
Chris@16:                 return proto::value(*this);
Chris@16:             }
Chris@16: 
Chris@16:             const_reference get() const
Chris@16:             {
Chris@16:                 return proto::value(*this);
Chris@16:             }
Chris@16:         };
Chris@16:     }
Chris@16: 
Chris@16:     /// \brief A helper function for creating a \c literal\<\> wrapper.
Chris@16:     /// \param t The object to wrap.
Chris@16:     /// \return literal\<T &\>(t)
Chris@16:     /// \attention The returned value holds the argument by reference.
Chris@16:     /// \throw nothrow
Chris@16:     template<typename T>
Chris@16:     inline literal<T &> const lit(T &t)
Chris@16:     {
Chris@16:         return literal<T &>(t);
Chris@16:     }
Chris@16: 
Chris@16:     /// \overload
Chris@16:     ///
Chris@16:     template<typename T>
Chris@16:     inline literal<T const &> const lit(T const &t)
Chris@16:     {
Chris@16:         #ifdef BOOST_MSVC
Chris@16:         #pragma warning(push)
Chris@16:         #pragma warning(disable: 4180) // warning C4180: qualifier applied to function type has no meaning; ignored
Chris@16:         #endif
Chris@16: 
Chris@16:         return literal<T const &>(t);
Chris@16: 
Chris@16:         #ifdef BOOST_MSVC
Chris@16:         #pragma warning(pop)
Chris@16:         #endif
Chris@16:     }
Chris@16: 
Chris@16: }}
Chris@16: 
Chris@16: #endif