Add boost::variant

boost/variant/detail/variant_io.hpp

@@ -0,0 +1,95 @@
+//-----------------------------------------------------------------------------
+// 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;
+    }
+
+private:
+    printer& operator=(const printer&);
+
+};
+
+}} // 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