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
22 namespace boost
23 {
24
25 template<class CharType, class CharTrait>
26 inline
27 std::basic_ostream<CharType, CharTrait>&
operator <<(std::basic_ostream<CharType,CharTrait> & out,none_t)28 operator<<(std::basic_ostream<CharType, CharTrait>& out, none_t)
29 {
30 if (out.good())
31 {
32 out << "--";
33 }
34
35 return out;
36 }
37
38 template<class CharType, class CharTrait, class T>
39 inline
40 std::basic_ostream<CharType, CharTrait>&
operator <<(std::basic_ostream<CharType,CharTrait> & out,optional<T> const & v)41 operator<<(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
53 template<class CharType, class CharTrait, class T>
54 inline
55 std::basic_istream<CharType, CharTrait>&
operator >>(std::basic_istream<CharType,CharTrait> & in,optional<T> & v)56 operator>>(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