//-----------------------------------------------------------------------------

// boost variant/detail/variant_io.hpp header file

// See http://www.boost.org for updates, documentation, and revision history.

//-----------------------------------------------------------------------------

//

// Copyright (c) 2002-2003

// Eric Friedman, Itay Maman

//

// 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_VARIANT_DETAIL_VARIANT_IO_HPP

#define BOOST_VARIANT_DETAIL_VARIANT_IO_HPP

#include <iosfwd> // for std::basic_ostream forward declare

#include "boost/variant/variant_fwd.hpp"

#include "boost/detail/templated_streams.hpp"

#include "boost/variant/static_visitor.hpp"

namespace boost {

///////////////////////////////////////////////////////////////////////////////

// function template operator<<

//

// Outputs the content of the given variant to the given ostream.

//

// forward declare (allows output of embedded variant< variant< ... >, ... >)

template <

      BOOST_TEMPLATED_STREAM_ARGS(E,T)

    BOOST_TEMPLATED_STREAM_COMMA

      BOOST_VARIANT_ENUM_PARAMS(typename U)

    >

inline BOOST_TEMPLATED_STREAM(ostream, E,T)& operator<<(

      BOOST_TEMPLATED_STREAM(ostream, E,T)& out

    , const variant< BOOST_VARIANT_ENUM_PARAMS(U) >& rhs

    );

namespace detail { namespace variant {

template <typename OStream>

class printer

    : public boost::static_visitor<>

{

private: // representation

    OStream& out_;

public: // structors

    explicit printer(OStream& out)

        : out_( out )

    {

    }

public: // visitor interface

    template <typename T>

    void operator()(const T& operand) const

    {

        out_ << operand;

    }

};

}} // namespace detail::variant

template <

      BOOST_TEMPLATED_STREAM_ARGS(E,T)

    BOOST_TEMPLATED_STREAM_COMMA

      BOOST_VARIANT_ENUM_PARAMS(typename U)

    >

inline BOOST_TEMPLATED_STREAM(ostream, E,T)& operator<<(

      BOOST_TEMPLATED_STREAM(ostream, E,T)& out

    , const variant< BOOST_VARIANT_ENUM_PARAMS(U) >& rhs

    )

{

    detail::variant::printer<

          BOOST_TEMPLATED_STREAM(ostream, E,T)

        > visitor(out);

    rhs.apply_visitor(visitor);

    return out;

}

} // namespace boost

#endif // BOOST_VARIANT_DETAIL_VARIANT_IO_HPP