1// Stream iterators 2 3// Copyright (C) 2001, 2004, 2005 Free Software Foundation, Inc. 4// 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 2, or (at your option) 9// any later version. 10 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. 15 16// You should have received a copy of the GNU General Public License along 17// with this library; see the file COPYING. If not, write to the Free 18// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 19// USA. 20 21// As a special exception, you may use this file as part of a free software 22// library without restriction. Specifically, if other files instantiate 23// templates or use macros or inline functions from this file, or you compile 24// this file and link it with other files to produce an executable, this 25// file does not by itself cause the resulting executable to be covered by 26// the GNU General Public License. This exception does not however 27// invalidate any other reasons why the executable file might be covered by 28// the GNU General Public License. 29 30/** @file stream_iterator.h 31 * This is an internal header file, included by other library headers. 32 * You should not attempt to use it directly. 33 */ 34 35#ifndef _STREAM_ITERATOR_H 36#define _STREAM_ITERATOR_H 1 37 38#pragma GCC system_header 39 40#include <debug/debug.h> 41 42_GLIBCXX_BEGIN_NAMESPACE(std) 43 44 /// Provides input iterator semantics for streams. 45 template<typename _Tp, typename _CharT = char, 46 typename _Traits = char_traits<_CharT>, typename _Dist = ptrdiff_t> 47 class istream_iterator 48 : public iterator<input_iterator_tag, _Tp, _Dist, const _Tp*, const _Tp&> 49 { 50 public: 51 typedef _CharT char_type; 52 typedef _Traits traits_type; 53 typedef basic_istream<_CharT, _Traits> istream_type; 54 55 private: 56 istream_type* _M_stream; 57 _Tp _M_value; 58 bool _M_ok; 59 60 public: 61 /// Construct end of input stream iterator. 62 istream_iterator() 63 : _M_stream(0), _M_value(), _M_ok(false) {} 64 65 /// Construct start of input stream iterator. 66 istream_iterator(istream_type& __s) 67 : _M_stream(&__s) 68 { _M_read(); } 69 70 istream_iterator(const istream_iterator& __obj) 71 : _M_stream(__obj._M_stream), _M_value(__obj._M_value), 72 _M_ok(__obj._M_ok) 73 { } 74 75 const _Tp& 76 operator*() const 77 { 78 __glibcxx_requires_cond(_M_ok, 79 _M_message(__gnu_debug::__msg_deref_istream) 80 ._M_iterator(*this)); 81 return _M_value; 82 } 83 84 const _Tp* 85 operator->() const { return &(operator*()); } 86 87 istream_iterator& 88 operator++() 89 { 90 __glibcxx_requires_cond(_M_ok, 91 _M_message(__gnu_debug::__msg_inc_istream) 92 ._M_iterator(*this)); 93 _M_read(); 94 return *this; 95 } 96 97 istream_iterator 98 operator++(int) 99 { 100 __glibcxx_requires_cond(_M_ok, 101 _M_message(__gnu_debug::__msg_inc_istream) 102 ._M_iterator(*this)); 103 istream_iterator __tmp = *this; 104 _M_read(); 105 return __tmp; 106 } 107 108 bool 109 _M_equal(const istream_iterator& __x) const 110 { return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream); } 111 112 private: 113 void 114 _M_read() 115 { 116 _M_ok = (_M_stream && *_M_stream) ? true : false; 117 if (_M_ok) 118 { 119 *_M_stream >> _M_value; 120 _M_ok = *_M_stream ? true : false; 121 } 122 } 123 }; 124 125 /// Return true if x and y are both end or not end, or x and y are the same. 126 template<typename _Tp, typename _CharT, typename _Traits, typename _Dist> 127 inline bool 128 operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x, 129 const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y) 130 { return __x._M_equal(__y); } 131 132 /// Return false if x and y are both end or not end, or x and y are the same. 133 template <class _Tp, class _CharT, class _Traits, class _Dist> 134 inline bool 135 operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x, 136 const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y) 137 { return !__x._M_equal(__y); } 138 139 /** 140 * @brief Provides output iterator semantics for streams. 141 * 142 * This class provides an iterator to write to an ostream. The type Tp is 143 * the only type written by this iterator and there must be an 144 * operator<<(Tp) defined. 145 * 146 * @param Tp The type to write to the ostream. 147 * @param CharT The ostream char_type. 148 * @param Traits The ostream char_traits. 149 */ 150 template<typename _Tp, typename _CharT = char, 151 typename _Traits = char_traits<_CharT> > 152 class ostream_iterator 153 : public iterator<output_iterator_tag, void, void, void, void> 154 { 155 public: 156 //@{ 157 /// Public typedef 158 typedef _CharT char_type; 159 typedef _Traits traits_type; 160 typedef basic_ostream<_CharT, _Traits> ostream_type; 161 //@} 162 163 private: 164 ostream_type* _M_stream; 165 const _CharT* _M_string; 166 167 public: 168 /// Construct from an ostream. 169 ostream_iterator(ostream_type& __s) : _M_stream(&__s), _M_string(0) {} 170 171 /** 172 * Construct from an ostream. 173 * 174 * The delimiter string @a c is written to the stream after every Tp 175 * written to the stream. The delimiter is not copied, and thus must 176 * not be destroyed while this iterator is in use. 177 * 178 * @param s Underlying ostream to write to. 179 * @param c CharT delimiter string to insert. 180 */ 181 ostream_iterator(ostream_type& __s, const _CharT* __c) 182 : _M_stream(&__s), _M_string(__c) { } 183 184 /// Copy constructor. 185 ostream_iterator(const ostream_iterator& __obj) 186 : _M_stream(__obj._M_stream), _M_string(__obj._M_string) { } 187 188 /// Writes @a value to underlying ostream using operator<<. If 189 /// constructed with delimiter string, writes delimiter to ostream. 190 ostream_iterator& 191 operator=(const _Tp& __value) 192 { 193 __glibcxx_requires_cond(_M_stream != 0, 194 _M_message(__gnu_debug::__msg_output_ostream) 195 ._M_iterator(*this)); 196 *_M_stream << __value; 197 if (_M_string) *_M_stream << _M_string; 198 return *this; 199 } 200 201 ostream_iterator& 202 operator*() 203 { return *this; } 204 205 ostream_iterator& 206 operator++() 207 { return *this; } 208 209 ostream_iterator& 210 operator++(int) 211 { return *this; } 212 }; 213 214_GLIBCXX_END_NAMESPACE 215 216#endif 217