libstdc++
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00001 // Stream iterators 00002 00003 // Copyright (C) 2001, 2004, 2005, 2009, 2010 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(&__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 const _Tp& 00078 operator*() const 00079 { 00080 __glibcxx_requires_cond(_M_ok, 00081 _M_message(__gnu_debug::__msg_deref_istream) 00082 ._M_iterator(*this)); 00083 return _M_value; 00084 } 00085 00086 const _Tp* 00087 operator->() const { return &(operator*()); } 00088 00089 istream_iterator& 00090 operator++() 00091 { 00092 __glibcxx_requires_cond(_M_ok, 00093 _M_message(__gnu_debug::__msg_inc_istream) 00094 ._M_iterator(*this)); 00095 _M_read(); 00096 return *this; 00097 } 00098 00099 istream_iterator 00100 operator++(int) 00101 { 00102 __glibcxx_requires_cond(_M_ok, 00103 _M_message(__gnu_debug::__msg_inc_istream) 00104 ._M_iterator(*this)); 00105 istream_iterator __tmp = *this; 00106 _M_read(); 00107 return __tmp; 00108 } 00109 00110 bool 00111 _M_equal(const istream_iterator& __x) const 00112 { return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream); } 00113 00114 private: 00115 void 00116 _M_read() 00117 { 00118 _M_ok = (_M_stream && *_M_stream) ? true : false; 00119 if (_M_ok) 00120 { 00121 *_M_stream >> _M_value; 00122 _M_ok = *_M_stream ? true : false; 00123 } 00124 } 00125 }; 00126 00127 /// Return true if x and y are both end or not end, or x and y are the same. 00128 template<typename _Tp, typename _CharT, typename _Traits, typename _Dist> 00129 inline bool 00130 operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x, 00131 const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y) 00132 { return __x._M_equal(__y); } 00133 00134 /// Return false if x and y are both end or not end, or x and y are the same. 00135 template <class _Tp, class _CharT, class _Traits, class _Dist> 00136 inline bool 00137 operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x, 00138 const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y) 00139 { return !__x._M_equal(__y); } 00140 00141 /** 00142 * @brief Provides output iterator semantics for streams. 00143 * 00144 * This class provides an iterator to write to an ostream. The type Tp is 00145 * the only type written by this iterator and there must be an 00146 * operator<<(Tp) defined. 00147 * 00148 * @tparam _Tp The type to write to the ostream. 00149 * @tparam _CharT The ostream char_type. 00150 * @tparam _Traits The ostream char_traits. 00151 */ 00152 template<typename _Tp, typename _CharT = char, 00153 typename _Traits = char_traits<_CharT> > 00154 class ostream_iterator 00155 : public iterator<output_iterator_tag, void, void, void, void> 00156 { 00157 public: 00158 //@{ 00159 /// Public typedef 00160 typedef _CharT char_type; 00161 typedef _Traits traits_type; 00162 typedef basic_ostream<_CharT, _Traits> ostream_type; 00163 //@} 00164 00165 private: 00166 ostream_type* _M_stream; 00167 const _CharT* _M_string; 00168 00169 public: 00170 /// Construct from an ostream. 00171 ostream_iterator(ostream_type& __s) : _M_stream(&__s), _M_string(0) {} 00172 00173 /** 00174 * Construct from an ostream. 00175 * 00176 * The delimiter string @a c is written to the stream after every Tp 00177 * written to the stream. The delimiter is not copied, and thus must 00178 * not be destroyed while this iterator is in use. 00179 * 00180 * @param __s Underlying ostream to write to. 00181 * @param __c CharT delimiter string to insert. 00182 */ 00183 ostream_iterator(ostream_type& __s, const _CharT* __c) 00184 : _M_stream(&__s), _M_string(__c) { } 00185 00186 /// Copy constructor. 00187 ostream_iterator(const ostream_iterator& __obj) 00188 : _M_stream(__obj._M_stream), _M_string(__obj._M_string) { } 00189 00190 /// Writes @a value to underlying ostream using operator<<. If 00191 /// constructed with delimiter string, writes delimiter to ostream. 00192 ostream_iterator& 00193 operator=(const _Tp& __value) 00194 { 00195 __glibcxx_requires_cond(_M_stream != 0, 00196 _M_message(__gnu_debug::__msg_output_ostream) 00197 ._M_iterator(*this)); 00198 *_M_stream << __value; 00199 if (_M_string) *_M_stream << _M_string; 00200 return *this; 00201 } 00202 00203 ostream_iterator& 00204 operator*() 00205 { return *this; } 00206 00207 ostream_iterator& 00208 operator++() 00209 { return *this; } 00210 00211 ostream_iterator& 00212 operator++(int) 00213 { return *this; } 00214 }; 00215 00216 // @} group iterators 00217 00218 _GLIBCXX_END_NAMESPACE_VERSION 00219 } // namespace 00220 00221 #endif