1//-----------------------------------------------------------------------------
2// boost variant/detail/variant_io.hpp header file
3// See http://www.boost.org for updates, documentation, and revision history.
4//-----------------------------------------------------------------------------
5//
6// Copyright (c) 2002-2003
7// Eric Friedman, Itay Maman
8//
9// Distributed under the Boost Software License, Version 1.0. (See
10// accompanying file LICENSE_1_0.txt or copy at
11// http://www.boost.org/LICENSE_1_0.txt)
12
13#ifndef BOOST_VARIANT_DETAIL_VARIANT_IO_HPP
14#define BOOST_VARIANT_DETAIL_VARIANT_IO_HPP
15
16#include <iosfwd> // for std::basic_ostream forward declare
17
18#include <boost/variant/variant_fwd.hpp>
19
20#include <boost/detail/templated_streams.hpp>
21#include <boost/variant/static_visitor.hpp>
22
23namespace boost {
24
25///////////////////////////////////////////////////////////////////////////////
26// function template operator<<
27//
28// Outputs the content of the given variant to the given ostream.
29//
30
31// forward declare (allows output of embedded variant< variant< ... >, ... >)
32template <
33 BOOST_TEMPLATED_STREAM_ARGS(E,T)
34 BOOST_TEMPLATED_STREAM_COMMA
35 BOOST_VARIANT_ENUM_PARAMS(typename U)
36 >
37inline BOOST_TEMPLATED_STREAM(ostream, E,T)& operator<<(
38 BOOST_TEMPLATED_STREAM(ostream, E,T)& out
39 , const variant< BOOST_VARIANT_ENUM_PARAMS(U) >& rhs
40 );
41
42namespace detail { namespace variant {
43
44template <typename OStream>
45class printer
46 : public boost::static_visitor<>
47{
48private: // representation
49
50 OStream& out_;
51
52public: // structors
53
54 explicit printer(OStream& out)
55 : out_( out )
56 {
57 }
58
59public: // visitor interface
60
61 template <typename T>
62 void operator()(const T& operand) const
63 {
64 out_ << operand;
65 }
66
67private:
68 printer& operator=(const printer&);
69
70};
71
72}} // namespace detail::variant
73
74template <
75 BOOST_TEMPLATED_STREAM_ARGS(E,T)
76 BOOST_TEMPLATED_STREAM_COMMA
77 BOOST_VARIANT_ENUM_PARAMS(typename U)
78 >
79inline BOOST_TEMPLATED_STREAM(ostream, E,T)& operator<<(
80 BOOST_TEMPLATED_STREAM(ostream, E,T)& out
81 , const variant< BOOST_VARIANT_ENUM_PARAMS(U) >& rhs
82 )
83{
84 detail::variant::printer<
85 BOOST_TEMPLATED_STREAM(ostream, E,T)
86 > visitor(out);
87
88 rhs.apply_visitor(visitor);
89
90 return out;
91}
92
93} // namespace boost
94
95#endif // BOOST_VARIANT_DETAIL_VARIANT_IO_HPP
96