1// Copyright (C) 2005, Fernando Luis Cacciola Carballal.
2//
3// Use, modification, and distribution is subject to the Boost Software
4// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
5// http://www.boost.org/LICENSE_1_0.txt)
6//
7// See http://www.boost.org/libs/optional for documentation.
8//
9// You are welcome to contact the author at:
10// fernando_cacciola@hotmail.com
11//
12#ifndef BOOST_OPTIONAL_OPTIONAL_IO_FLC_19NOV2002_HPP
13#define BOOST_OPTIONAL_OPTIONAL_IO_FLC_19NOV2002_HPP
14
15#include <istream>
16#include <ostream>
17
18#include "boost/none.hpp"
19#include "boost/optional/optional.hpp"
20
21
22namespace boost
23{
24
25template<class CharType, class CharTrait>
26inline
27std::basic_ostream<CharType, CharTrait>&
28operator<<(std::basic_ostream<CharType, CharTrait>& out, none_t)
29{
30 if (out.good())
31 {
32 out << "--";
33 }
34
35 return out;
36}
37
38template<class CharType, class CharTrait, class T>
39inline
40std::basic_ostream<CharType, CharTrait>&
41operator<<(std::basic_ostream<CharType, CharTrait>& out, optional<T> const& v)
42{
43 if (out.good())
44 {
45 if (!v)
46 out << "--" ;
47 else out << ' ' << *v ;
48 }
49
50 return out;
51}
52
53template<class CharType, class CharTrait, class T>
54inline
55std::basic_istream<CharType, CharTrait>&
56operator>>(std::basic_istream<CharType, CharTrait>& in, optional<T>& v)
57{
58 if (in.good())
59 {
60 int d = in.get();
61 if (d == ' ')
62 {
63 T x;
64 in >> x;
65#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
66 v = boost::move(x);
67#else
68 v = x;
69#endif
70 }
71 else
72 {
73 if (d == '-')
74 {
75 d = in.get();
76
77 if (d == '-')
78 {
79 v = none;
80 return in;
81 }
82 }
83
84 in.setstate( std::ios::failbit );
85 }
86 }
87
88 return in;
89}
90
91} // namespace boost
92
93#endif
94
95

source code of boost/boost/optional/optional_io.hpp