3 // Copyright (C) 2001-2021 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 /** @file bits/stream_iterator.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{iterator}
30 #ifndef _STREAM_ITERATOR_H
31 #define _STREAM_ITERATOR_H 1
33 #pragma GCC system_header
35 #include <debug/debug.h>
37 namespace std
_GLIBCXX_VISIBILITY(default)
39 _GLIBCXX_BEGIN_NAMESPACE_VERSION
42 * @addtogroup iterators
46 /// Provides input iterator semantics for streams.
47 template<typename _Tp
, typename _CharT
= char,
48 typename _Traits
= char_traits
<_CharT
>, typename _Dist
= ptrdiff_t>
49 class istream_iterator
50 : public iterator
<input_iterator_tag
, _Tp
, _Dist
, const _Tp
*, const _Tp
&>
53 typedef _CharT char_type
;
54 typedef _Traits traits_type
;
55 typedef basic_istream
<_CharT
, _Traits
> istream_type
;
58 istream_type
* _M_stream
;
60 // This bool becomes false at end-of-stream. It should be sufficient to
61 // check _M_stream != nullptr instead, but historically we did not set
62 // _M_stream to null when reaching the end, so we need to keep this flag.
66 /// Construct end of input stream iterator.
67 _GLIBCXX_CONSTEXPR
istream_iterator()
68 : _M_stream(0), _M_value(), _M_ok(false) {}
70 /// Construct start of input stream iterator.
71 istream_iterator(istream_type
& __s
)
72 : _M_stream(std::__addressof(__s
)), _M_ok(true)
75 istream_iterator(const istream_iterator
& __obj
)
76 : _M_stream(__obj
._M_stream
), _M_value(__obj
._M_value
),
80 #if __cplusplus > 201703L && __cpp_lib_concepts
82 istream_iterator(default_sentinel_t
)
83 noexcept(is_nothrow_default_constructible_v
<_Tp
>)
84 : istream_iterator() { }
87 #if __cplusplus >= 201103L
88 istream_iterator
& operator=(const istream_iterator
&) = default;
89 ~istream_iterator() = default;
95 __glibcxx_requires_cond(_M_ok
,
96 _M_message(__gnu_debug::__msg_deref_istream
)
102 operator->() const { return std::__addressof((operator*())); }
107 __glibcxx_requires_cond(_M_ok
,
108 _M_message(__gnu_debug::__msg_inc_istream
)
109 ._M_iterator(*this));
117 __glibcxx_requires_cond(_M_ok
,
118 _M_message(__gnu_debug::__msg_inc_istream
)
119 ._M_iterator(*this));
120 istream_iterator __tmp
= *this;
127 _M_equal(const istream_iterator
& __x
) const
129 // Ideally this would just return _M_stream == __x._M_stream,
130 // but code compiled with old versions never sets _M_stream to null.
131 return (_M_ok
== __x
._M_ok
) && (!_M_ok
|| _M_stream
== __x
._M_stream
);
137 if (_M_stream
&& !(*_M_stream
>> _M_value
))
144 /// Return true if the iterators refer to the same stream,
145 /// or are both at end-of-stream.
147 operator==(const istream_iterator
& __x
, const istream_iterator
& __y
)
148 { return __x
._M_equal(__y
); }
150 /// Return true if the iterators refer to different streams,
151 /// or if one is at end-of-stream and the other is not.
153 operator!=(const istream_iterator
& __x
, const istream_iterator
& __y
)
154 { return !__x
._M_equal(__y
); }
156 #if __cplusplus > 201703L && __cpp_lib_concepts
158 operator==(const istream_iterator
& __i
, default_sentinel_t
)
159 { return !__i
._M_stream
; }
164 * @brief Provides output iterator semantics for streams.
166 * This class provides an iterator to write to an ostream. The type Tp is
167 * the only type written by this iterator and there must be an
168 * operator<<(Tp) defined.
170 * @tparam _Tp The type to write to the ostream.
171 * @tparam _CharT The ostream char_type.
172 * @tparam _Traits The ostream char_traits.
174 template<typename _Tp
, typename _CharT
= char,
175 typename _Traits
= char_traits
<_CharT
> >
176 class ostream_iterator
177 : public iterator
<output_iterator_tag
, void, void, void, void>
182 #if __cplusplus > 201703L
183 using difference_type
= ptrdiff_t;
185 typedef _CharT char_type
;
186 typedef _Traits traits_type
;
187 typedef basic_ostream
<_CharT
, _Traits
> ostream_type
;
191 ostream_type
* _M_stream
;
192 const _CharT
* _M_string
;
195 #if __cplusplus > 201703L
196 constexpr ostream_iterator() noexcept
197 : _M_stream(nullptr), _M_string(nullptr) { }
200 /// Construct from an ostream.
201 ostream_iterator(ostream_type
& __s
)
202 : _M_stream(std::__addressof(__s
)), _M_string(0) {}
205 * Construct from an ostream.
207 * The delimiter string @a c is written to the stream after every Tp
208 * written to the stream. The delimiter is not copied, and thus must
209 * not be destroyed while this iterator is in use.
211 * @param __s Underlying ostream to write to.
212 * @param __c CharT delimiter string to insert.
214 ostream_iterator(ostream_type
& __s
, const _CharT
* __c
)
215 : _M_stream(std::__addressof(__s
)), _M_string(__c
) { }
217 /// Copy constructor.
218 ostream_iterator(const ostream_iterator
& __obj
)
219 : _M_stream(__obj
._M_stream
), _M_string(__obj
._M_string
) { }
221 #if __cplusplus >= 201103L
222 ostream_iterator
& operator=(const ostream_iterator
&) = default;
225 /// Writes @a value to underlying ostream using operator<<. If
226 /// constructed with delimiter string, writes delimiter to ostream.
228 operator=(const _Tp
& __value
)
230 __glibcxx_requires_cond(_M_stream
!= 0,
231 _M_message(__gnu_debug::__msg_output_ostream
)
232 ._M_iterator(*this));
233 *_M_stream
<< __value
;
235 *_M_stream
<< _M_string
;
252 /// @} group iterators
254 _GLIBCXX_END_NAMESPACE_VERSION