123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270 |
- // Stream iterators
- // Copyright (C) 2001-2022 Free Software Foundation, Inc.
- //
- // This file is part of the GNU ISO C++ Library. This library is free
- // software; you can redistribute it and/or modify it under the
- // terms of the GNU General Public License as published by the
- // Free Software Foundation; either version 3, or (at your option)
- // any later version.
- // This library is distributed in the hope that it will be useful,
- // but WITHOUT ANY WARRANTY; without even the implied warranty of
- // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- // GNU General Public License for more details.
- // Under Section 7 of GPL version 3, you are granted additional
- // permissions described in the GCC Runtime Library Exception, version
- // 3.1, as published by the Free Software Foundation.
- // You should have received a copy of the GNU General Public License and
- // a copy of the GCC Runtime Library Exception along with this program;
- // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
- // <http://www.gnu.org/licenses/>.
- /** @file bits/stream_iterator.h
- * This is an internal header file, included by other library headers.
- * Do not attempt to use it directly. @headername{iterator}
- */
- #ifndef _STREAM_ITERATOR_H
- #define _STREAM_ITERATOR_H 1
- #pragma GCC system_header
- #include <debug/debug.h>
- namespace std _GLIBCXX_VISIBILITY(default)
- {
- _GLIBCXX_BEGIN_NAMESPACE_VERSION
- /**
- * @addtogroup iterators
- * @{
- */
- // Ignore warnings about std::iterator.
- #pragma GCC diagnostic push
- #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
- /// Provides input iterator semantics for streams.
- template<typename _Tp, typename _CharT = char,
- typename _Traits = char_traits<_CharT>, typename _Dist = ptrdiff_t>
- class istream_iterator
- : public iterator<input_iterator_tag, _Tp, _Dist, const _Tp*, const _Tp&>
- {
- public:
- typedef _CharT char_type;
- typedef _Traits traits_type;
- typedef basic_istream<_CharT, _Traits> istream_type;
- private:
- istream_type* _M_stream;
- _Tp _M_value;
- // This bool becomes false at end-of-stream. It should be sufficient to
- // check _M_stream != nullptr instead, but historically we did not set
- // _M_stream to null when reaching the end, so we need to keep this flag.
- bool _M_ok;
- public:
- /// Construct end of input stream iterator.
- _GLIBCXX_CONSTEXPR istream_iterator()
- _GLIBCXX_NOEXCEPT_IF(is_nothrow_default_constructible<_Tp>::value)
- : _M_stream(0), _M_value(), _M_ok(false) {}
- /// Construct start of input stream iterator.
- istream_iterator(istream_type& __s)
- : _M_stream(std::__addressof(__s)), _M_ok(true)
- { _M_read(); }
- istream_iterator(const istream_iterator& __obj)
- _GLIBCXX_NOEXCEPT_IF(is_nothrow_copy_constructible<_Tp>::value)
- : _M_stream(__obj._M_stream), _M_value(__obj._M_value),
- _M_ok(__obj._M_ok)
- { }
- #if __cplusplus > 201703L && __cpp_lib_concepts
- constexpr
- istream_iterator(default_sentinel_t)
- noexcept(is_nothrow_default_constructible_v<_Tp>)
- : istream_iterator() { }
- #endif
- #if __cplusplus >= 201103L
- istream_iterator& operator=(const istream_iterator&) = default;
- ~istream_iterator() = default;
- #endif
- _GLIBCXX_NODISCARD
- const _Tp&
- operator*() const _GLIBCXX_NOEXCEPT
- {
- __glibcxx_requires_cond(_M_ok,
- _M_message(__gnu_debug::__msg_deref_istream)
- ._M_iterator(*this));
- return _M_value;
- }
- _GLIBCXX_NODISCARD
- const _Tp*
- operator->() const _GLIBCXX_NOEXCEPT
- { return std::__addressof((operator*())); }
- istream_iterator&
- operator++()
- {
- __glibcxx_requires_cond(_M_ok,
- _M_message(__gnu_debug::__msg_inc_istream)
- ._M_iterator(*this));
- _M_read();
- return *this;
- }
- istream_iterator
- operator++(int)
- {
- __glibcxx_requires_cond(_M_ok,
- _M_message(__gnu_debug::__msg_inc_istream)
- ._M_iterator(*this));
- istream_iterator __tmp = *this;
- _M_read();
- return __tmp;
- }
- private:
- bool
- _M_equal(const istream_iterator& __x) const _GLIBCXX_NOEXCEPT
- {
- // Ideally this would just return _M_stream == __x._M_stream,
- // but code compiled with old versions never sets _M_stream to null.
- return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream);
- }
- void
- _M_read()
- {
- if (_M_stream && !(*_M_stream >> _M_value))
- {
- _M_stream = 0;
- _M_ok = false;
- }
- }
- /// Return true if the iterators refer to the same stream,
- /// or are both at end-of-stream.
- _GLIBCXX_NODISCARD
- friend bool
- operator==(const istream_iterator& __x, const istream_iterator& __y)
- _GLIBCXX_NOEXCEPT
- { return __x._M_equal(__y); }
- #if __cpp_impl_three_way_comparison < 201907L
- /// Return true if the iterators refer to different streams,
- /// or if one is at end-of-stream and the other is not.
- _GLIBCXX_NODISCARD
- friend bool
- operator!=(const istream_iterator& __x, const istream_iterator& __y)
- _GLIBCXX_NOEXCEPT
- { return !__x._M_equal(__y); }
- #endif
- #if __cplusplus > 201703L && __cpp_lib_concepts
- [[nodiscard]]
- friend bool
- operator==(const istream_iterator& __i, default_sentinel_t) noexcept
- { return !__i._M_stream; }
- #endif
- };
- /**
- * @brief Provides output iterator semantics for streams.
- *
- * This class provides an iterator to write to an ostream. The type Tp is
- * the only type written by this iterator and there must be an
- * operator<<(Tp) defined.
- *
- * @tparam _Tp The type to write to the ostream.
- * @tparam _CharT The ostream char_type.
- * @tparam _Traits The ostream char_traits.
- */
- template<typename _Tp, typename _CharT = char,
- typename _Traits = char_traits<_CharT> >
- class ostream_iterator
- : public iterator<output_iterator_tag, void, void, void, void>
- {
- public:
- ///@{
- /// Public typedef
- #if __cplusplus > 201703L
- using difference_type = ptrdiff_t;
- #endif
- typedef _CharT char_type;
- typedef _Traits traits_type;
- typedef basic_ostream<_CharT, _Traits> ostream_type;
- ///@}
- private:
- ostream_type* _M_stream;
- const _CharT* _M_string;
- public:
- /// Construct from an ostream.
- ostream_iterator(ostream_type& __s) _GLIBCXX_NOEXCEPT
- : _M_stream(std::__addressof(__s)), _M_string(0) {}
- /**
- * Construct from an ostream.
- *
- * The delimiter string @a c is written to the stream after every Tp
- * written to the stream. The delimiter is not copied, and thus must
- * not be destroyed while this iterator is in use.
- *
- * @param __s Underlying ostream to write to.
- * @param __c CharT delimiter string to insert.
- */
- ostream_iterator(ostream_type& __s, const _CharT* __c) _GLIBCXX_NOEXCEPT
- : _M_stream(std::__addressof(__s)), _M_string(__c) { }
- /// Copy constructor.
- ostream_iterator(const ostream_iterator& __obj) _GLIBCXX_NOEXCEPT
- : _M_stream(__obj._M_stream), _M_string(__obj._M_string) { }
- #if __cplusplus >= 201103L
- ostream_iterator& operator=(const ostream_iterator&) = default;
- #endif
- /// Writes @a value to underlying ostream using operator<<. If
- /// constructed with delimiter string, writes delimiter to ostream.
- ostream_iterator&
- operator=(const _Tp& __value)
- {
- __glibcxx_requires_cond(_M_stream != 0,
- _M_message(__gnu_debug::__msg_output_ostream)
- ._M_iterator(*this));
- *_M_stream << __value;
- if (_M_string)
- *_M_stream << _M_string;
- return *this;
- }
- _GLIBCXX_NODISCARD
- ostream_iterator&
- operator*() _GLIBCXX_NOEXCEPT
- { return *this; }
- ostream_iterator&
- operator++() _GLIBCXX_NOEXCEPT
- { return *this; }
- ostream_iterator&
- operator++(int) _GLIBCXX_NOEXCEPT
- { return *this; }
- };
- #pragma GCC diagnostic pop
- /// @} group iterators
- _GLIBCXX_END_NAMESPACE_VERSION
- } // namespace
- #endif
|