// (C) Copyright Jonathan Turkanis 2005.

// 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.)

// See http://www.boost.org/libs/iostreams for documentation.

#ifndef BOOST_IOSTREAMS_TEE_HPP_INCLUDED

#define BOOST_IOSTREAMS_TEE_HPP_INCLUDED

#if defined(_MSC_VER) && (_MSC_VER >= 1020)

# pragma once

#endif

#include <cassert>

#include <boost/config.hpp>  // BOOST_DEDUCE_TYPENAME.

#include <boost/iostreams/categories.hpp>

#include <boost/iostreams/detail/adapter/basic_adapter.hpp>

#include <boost/iostreams/detail/call_traits.hpp>

#include <boost/iostreams/detail/closer.hpp>

#include <boost/iostreams/operations.hpp>

#include <boost/iostreams/pipeline.hpp>

#include <boost/iostreams/traits.hpp>

#include <boost/static_assert.hpp>

#include <boost/type_traits/is_convertible.hpp>

#include <boost/type_traits/is_same.hpp>

namespace boost { namespace iostreams {

//

// Template name: tee_filter.

// Template paramters:

//      Device - A blocking Sink.

//

template<typename Device>

class tee_filter : public detail::basic_adapter<Device> {

public:

    typedef typename detail::param_type<Device>::type  param_type;

    typedef typename char_type_of<Device>::type        char_type;

    struct category

        : multichar_output_filter_tag,

          closable_tag,

          flushable_tag,

          localizable_tag,

          optimally_buffered_tag

        { };

    BOOST_STATIC_ASSERT((

        is_convertible< // Using mode_of causes failures on VC6-7.0.

            BOOST_DEDUCED_TYPENAME iostreams::category_of<Device>::type, output

        >::value

    ));

    explicit tee_filter(param_type dev) 

        : detail::basic_adapter<Device>(dev) 

        { }

    template<typename Sink>

    std::streamsize write(Sink& snk, const char_type* s, std::streamsize n)

    {

        std::streamsize result = iostreams::write(snk, s, n);

        std::streamsize result2 = iostreams::write(this->component(), s, result);

        (void) result2; // Suppress 'unused variable' warning.

        assert(result == result2);

        return result;

    }

    template<typename Next>

    void close( Next&,

                BOOST_IOS::openmode which =

                    BOOST_IOS::in | BOOST_IOS::out )

    { iostreams::close(this->component(), which); }

    template<typename Sink>

    bool flush(Sink& snk)

    {

        bool r1 = iostreams::flush(snk);

        bool r2 = iostreams::flush(this->component());

        return r1 && r2;

    }

};

BOOST_IOSTREAMS_PIPABLE(tee_filter, 1)

//

// Template name: tee_device.

// Template paramters:

//      Sink1 - A blocking Sink.

//      Sink2 - A blocking Sink.

//

template<typename Sink1, typename Sink2>

class tee_device {

public:

    typedef typename detail::param_type<Sink1>::type  param_type1;

    typedef typename detail::param_type<Sink2>::type  param_type2;

    typedef typename detail::value_type<Sink1>::type  value_type1;

    typedef typename detail::value_type<Sink2>::type  value_type2;

    typedef typename char_type_of<Sink1>::type        char_type;

    BOOST_STATIC_ASSERT((

        is_same<

            char_type, 

            BOOST_DEDUCED_TYPENAME char_type_of<Sink2>::type

        >::value

    ));

    BOOST_STATIC_ASSERT((

        is_convertible< // Using mode_of causes failures on VC6-7.0.

            BOOST_DEDUCED_TYPENAME iostreams::category_of<Sink1>::type, output

        >::value

    ));

    BOOST_STATIC_ASSERT((

        is_convertible< // Using mode_of causes failures on VC6-7.0.

            BOOST_DEDUCED_TYPENAME iostreams::category_of<Sink2>::type, output

        >::value

    ));

    struct category

        : output,

          device_tag,

          closable_tag,

          flushable_tag,

          localizable_tag,

          optimally_buffered_tag

        { };

    tee_device(param_type1 sink1, param_type2 sink2) 

        : sink1_(sink1), sink2_(sink2)

        { }

    std::streamsize write(const char_type* s, std::streamsize n)

    {

        std::streamsize result1 = iostreams::write(sink1_, s, n);

        std::streamsize result2 = iostreams::write(sink2_, s, n);

        (void) result1; // Suppress 'unused variable' warning.

        (void) result2;

        assert(result1 == n && result2 == n);

        return n;

    }

    void close(BOOST_IOS::openmode which = BOOST_IOS::in | BOOST_IOS::out)

    { 

        detail::external_closer<Sink2> close2(sink2_, which);

        detail::external_closer<Sink1> close1(sink1_, which);

    }

    bool flush()

    {

        bool r1 = iostreams::flush(sink1_);

        bool r2 = iostreams::flush(sink2_);

        return r1 && r2;

    }

    template<typename Locale>

    void imbue(const Locale& loc)

    {

        iostreams::imbue(sink1_, loc);

        iostreams::imbue(sink2_, loc);

    }

    std::streamsize optimal_buffer_size() const 

    {

        return (std::max) ( iostreams::optimal_buffer_size(sink1_), 

                            iostreams::optimal_buffer_size(sink2_) );

    }

private:

    value_type1 sink1_;

    value_type2 sink2_;

};

template<typename Sink>

tee_filter<Sink> tee(const Sink& snk) 

{ return tee_filter<Sink>(snk); }

template<typename Sink1, typename Sink2>

tee_device<Sink1, Sink2> tee(const Sink1& sink1, const Sink2& sink2) 

{ return tee_device<Sink1, Sink2>(sink1, sink2); }

} } // End namespaces iostreams, boost.

#endif // #ifndef BOOST_IOSTREAMS_TEE_HPP_INCLUDED