libstdc++
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00001 // Stream iterators 00002 00003 // Copyright (C) 2001-2019 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 3, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // Under Section 7 of GPL version 3, you are granted additional 00017 // permissions described in the GCC Runtime Library Exception, version 00018 // 3.1, as published by the Free Software Foundation. 00019 00020 // You should have received a copy of the GNU General Public License and 00021 // a copy of the GCC Runtime Library Exception along with this program; 00022 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00023 // <http://www.gnu.org/licenses/>. 00024 00025 /** @file bits/stream_iterator.h 00026 * This is an internal header file, included by other library headers. 00027 * Do not attempt to use it directly. @headername{iterator} 00028 */ 00029 00030 #ifndef _STREAM_ITERATOR_H 00031 #define _STREAM_ITERATOR_H 1 00032 00033 #pragma GCC system_header 00034 00035 #include <debug/debug.h> 00036 00037 namespace std _GLIBCXX_VISIBILITY(default) 00038 { 00039 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00040 00041 /** 00042 * @addtogroup iterators 00043 * @{ 00044 */ 00045 00046 /// Provides input iterator semantics for streams. 00047 template<typename _Tp, typename _CharT = char, 00048 typename _Traits = char_traits<_CharT>, typename _Dist = ptrdiff_t> 00049 class istream_iterator 00050 : public iterator<input_iterator_tag, _Tp, _Dist, const _Tp*, const _Tp&> 00051 { 00052 public: 00053 typedef _CharT char_type; 00054 typedef _Traits traits_type; 00055 typedef basic_istream<_CharT, _Traits> istream_type; 00056 00057 private: 00058 istream_type* _M_stream; 00059 _Tp _M_value; 00060 bool _M_ok; 00061 00062 public: 00063 /// Construct end of input stream iterator. 00064 _GLIBCXX_CONSTEXPR istream_iterator() 00065 : _M_stream(0), _M_value(), _M_ok(false) {} 00066 00067 /// Construct start of input stream iterator. 00068 istream_iterator(istream_type& __s) 00069 : _M_stream(std::__addressof(__s)) 00070 { _M_read(); } 00071 00072 istream_iterator(const istream_iterator& __obj) 00073 : _M_stream(__obj._M_stream), _M_value(__obj._M_value), 00074 _M_ok(__obj._M_ok) 00075 { } 00076 00077 #if __cplusplus >= 201103L 00078 istream_iterator& operator=(const istream_iterator&) = default; 00079 #endif 00080 00081 const _Tp& 00082 operator*() const 00083 { 00084 __glibcxx_requires_cond(_M_ok, 00085 _M_message(__gnu_debug::__msg_deref_istream) 00086 ._M_iterator(*this)); 00087 return _M_value; 00088 } 00089 00090 const _Tp* 00091 operator->() const { return std::__addressof((operator*())); } 00092 00093 istream_iterator& 00094 operator++() 00095 { 00096 __glibcxx_requires_cond(_M_ok, 00097 _M_message(__gnu_debug::__msg_inc_istream) 00098 ._M_iterator(*this)); 00099 _M_read(); 00100 return *this; 00101 } 00102 00103 istream_iterator 00104 operator++(int) 00105 { 00106 __glibcxx_requires_cond(_M_ok, 00107 _M_message(__gnu_debug::__msg_inc_istream) 00108 ._M_iterator(*this)); 00109 istream_iterator __tmp = *this; 00110 _M_read(); 00111 return __tmp; 00112 } 00113 00114 bool 00115 _M_equal(const istream_iterator& __x) const 00116 { return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream); } 00117 00118 private: 00119 void 00120 _M_read() 00121 { 00122 _M_ok = (_M_stream && *_M_stream) ? true : false; 00123 if (_M_ok) 00124 { 00125 *_M_stream >> _M_value; 00126 _M_ok = *_M_stream ? true : false; 00127 } 00128 } 00129 }; 00130 00131 /// Return true if x and y are both end or not end, or x and y are the same. 00132 template<typename _Tp, typename _CharT, typename _Traits, typename _Dist> 00133 inline bool 00134 operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x, 00135 const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y) 00136 { return __x._M_equal(__y); } 00137 00138 /// Return false if x and y are both end or not end, or x and y are the same. 00139 template <class _Tp, class _CharT, class _Traits, class _Dist> 00140 inline bool 00141 operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x, 00142 const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y) 00143 { return !__x._M_equal(__y); } 00144 00145 /** 00146 * @brief Provides output iterator semantics for streams. 00147 * 00148 * This class provides an iterator to write to an ostream. The type Tp is 00149 * the only type written by this iterator and there must be an 00150 * operator<<(Tp) defined. 00151 * 00152 * @tparam _Tp The type to write to the ostream. 00153 * @tparam _CharT The ostream char_type. 00154 * @tparam _Traits The ostream char_traits. 00155 */ 00156 template<typename _Tp, typename _CharT = char, 00157 typename _Traits = char_traits<_CharT> > 00158 class ostream_iterator 00159 : public iterator<output_iterator_tag, void, void, void, void> 00160 { 00161 public: 00162 //@{ 00163 /// Public typedef 00164 typedef _CharT char_type; 00165 typedef _Traits traits_type; 00166 typedef basic_ostream<_CharT, _Traits> ostream_type; 00167 //@} 00168 00169 private: 00170 ostream_type* _M_stream; 00171 const _CharT* _M_string; 00172 00173 public: 00174 /// Construct from an ostream. 00175 ostream_iterator(ostream_type& __s) 00176 : _M_stream(std::__addressof(__s)), _M_string(0) {} 00177 00178 /** 00179 * Construct from an ostream. 00180 * 00181 * The delimiter string @a c is written to the stream after every Tp 00182 * written to the stream. The delimiter is not copied, and thus must 00183 * not be destroyed while this iterator is in use. 00184 * 00185 * @param __s Underlying ostream to write to. 00186 * @param __c CharT delimiter string to insert. 00187 */ 00188 ostream_iterator(ostream_type& __s, const _CharT* __c) 00189 : _M_stream(&__s), _M_string(__c) { } 00190 00191 /// Copy constructor. 00192 ostream_iterator(const ostream_iterator& __obj) 00193 : _M_stream(__obj._M_stream), _M_string(__obj._M_string) { } 00194 00195 #if __cplusplus >= 201103L 00196 ostream_iterator& operator=(const ostream_iterator&) = default; 00197 #endif 00198 00199 /// Writes @a value to underlying ostream using operator<<. If 00200 /// constructed with delimiter string, writes delimiter to ostream. 00201 ostream_iterator& 00202 operator=(const _Tp& __value) 00203 { 00204 __glibcxx_requires_cond(_M_stream != 0, 00205 _M_message(__gnu_debug::__msg_output_ostream) 00206 ._M_iterator(*this)); 00207 *_M_stream << __value; 00208 if (_M_string) *_M_stream << _M_string; 00209 return *this; 00210 } 00211 00212 ostream_iterator& 00213 operator*() 00214 { return *this; } 00215 00216 ostream_iterator& 00217 operator++() 00218 { return *this; } 00219 00220 ostream_iterator& 00221 operator++(int) 00222 { return *this; } 00223 }; 00224 00225 // @} group iterators 00226 00227 _GLIBCXX_END_NAMESPACE_VERSION 00228 } // namespace 00229 00230 #endif