1 // Position types -*- C++ -*-
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4 // 2006, 2007, 2008, 2009, 2010
5 // Free Software Foundation, Inc.
7 // This file is part of the GNU ISO C++ Library. This library is free
8 // software; you can redistribute it and/or modify it under the
9 // terms of the GNU General Public License as published by the
10 // Free Software Foundation; either version 3, or (at your option)
13 // This library is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // Under Section 7 of GPL version 3, you are granted additional
19 // permissions described in the GCC Runtime Library Exception, version
20 // 3.1, as published by the Free Software Foundation.
22 // You should have received a copy of the GNU General Public License and
23 // a copy of the GCC Runtime Library Exception along with this program;
24 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
25 // <http://www.gnu.org/licenses/>.
27 /** @file bits/postypes.h
28 * This is an internal header file, included by other library headers.
29 * Do not attempt to use it directly. @headername{iosfwd}
33 // ISO C++ 14882: 27.4.1 - Types
34 // ISO C++ 14882: 27.4.3 - Template class fpos
37 #ifndef _GLIBCXX_POSTYPES_H
38 #define _GLIBCXX_POSTYPES_H 1
40 #pragma GCC system_header
42 #include <cwchar> // For mbstate_t
44 // XXX If <stdint.h> is really needed, make sure to define the macros
45 // before including it, in order not to break <tr1/cstdint> (and <cstdint>
46 // in C++0x). Reconsider all this as soon as possible...
47 #if (defined(_GLIBCXX_HAVE_INT64_T) && !defined(_GLIBCXX_HAVE_INT64_T_LONG) \
48 && !defined(_GLIBCXX_HAVE_INT64_T_LONG_LONG))
50 #ifndef __STDC_LIMIT_MACROS
51 # define _UNDEF__STDC_LIMIT_MACROS
52 # define __STDC_LIMIT_MACROS
54 #ifndef __STDC_CONSTANT_MACROS
55 # define _UNDEF__STDC_CONSTANT_MACROS
56 # define __STDC_CONSTANT_MACROS
58 #include <stdint.h> // For int64_t
59 #ifdef _UNDEF__STDC_LIMIT_MACROS
60 # undef __STDC_LIMIT_MACROS
61 # undef _UNDEF__STDC_LIMIT_MACROS
63 #ifdef _UNDEF__STDC_CONSTANT_MACROS
64 # undef __STDC_CONSTANT_MACROS
65 # undef _UNDEF__STDC_CONSTANT_MACROS
70 namespace std _GLIBCXX_VISIBILITY(default)
72 _GLIBCXX_BEGIN_NAMESPACE_VERSION
74 // The types streamoff, streampos and wstreampos and the class
75 // template fpos<> are described in clauses 21.1.2, 21.1.3, 27.1.2,
76 // 27.2, 27.4.1, 27.4.3 and D.6. Despite all this verbiage, the
77 // behaviour of these types is mostly implementation defined or
78 // unspecified. The behaviour in this implementation is as noted
82 * @brief Type used by fpos, char_traits<char>, and char_traits<wchar_t>.
84 * In clauses 21.1.3.1 and 27.4.1 streamoff is described as an
85 * implementation defined type.
86 * Note: In versions of GCC up to and including GCC 3.3, streamoff
89 #ifdef _GLIBCXX_HAVE_INT64_T_LONG
90 typedef long streamoff;
91 #elif defined(_GLIBCXX_HAVE_INT64_T_LONG_LONG)
92 typedef long long streamoff;
93 #elif defined(_GLIBCXX_HAVE_INT64_T)
94 typedef int64_t streamoff;
96 typedef long long streamoff;
99 /// Integral type for I/O operation counts and buffer sizes.
100 typedef ptrdiff_t streamsize; // Signed integral type
103 * @brief Class representing stream positions.
105 * The standard places no requirements upon the template parameter StateT.
106 * In this implementation StateT must be DefaultConstructible,
107 * CopyConstructible and Assignable. The standard only requires that fpos
108 * should contain a member of type StateT. In this implementation it also
109 * contains an offset stored as a signed integer.
111 * @param StateT Type passed to and returned from state().
113 template<typename _StateT>
121 // The standard doesn't require that fpos objects can be default
122 // constructed. This implementation provides a default
123 // constructor that initializes the offset to 0 and default
124 // constructs the state.
126 : _M_off(0), _M_state() { }
128 // The standard requires that fpos objects can be constructed
129 // from streamoff objects using the constructor syntax, and
130 // fails to give any meaningful semantics. In this
131 // implementation implicit conversion is also allowed, and this
132 // constructor stores the streamoff as the offset and default
133 // constructs the state.
134 /// Construct position from offset.
135 fpos(streamoff __off)
136 : _M_off(__off), _M_state() { }
138 /// Convert to streamoff.
139 operator streamoff() const { return _M_off; }
141 /// Remember the value of @a st.
146 /// Return the last set value of @a st.
151 // The standard requires that this operator must be defined, but
152 // gives no semantics. In this implementation it just adds its
153 // argument to the stored offset and returns *this.
154 /// Add offset to this position.
156 operator+=(streamoff __off)
162 // The standard requires that this operator must be defined, but
163 // gives no semantics. In this implementation it just subtracts
164 // its argument from the stored offset and returns *this.
165 /// Subtract offset from this position.
167 operator-=(streamoff __off)
173 // The standard requires that this operator must be defined, but
174 // defines its semantics only in terms of operator-. In this
175 // implementation it constructs a copy of *this, adds the
176 // argument to that copy using operator+= and then returns the
178 /// Add position and offset.
180 operator+(streamoff __off) const
187 // The standard requires that this operator must be defined, but
188 // defines its semantics only in terms of operator+. In this
189 // implementation it constructs a copy of *this, subtracts the
190 // argument from that copy using operator-= and then returns the
192 /// Subtract offset from position.
194 operator-(streamoff __off) const
201 // The standard requires that this operator must be defined, but
202 // defines its semantics only in terms of operator+. In this
203 // implementation it returns the difference between the offset
204 // stored in *this and in the argument.
205 /// Subtract position to return offset.
207 operator-(const fpos& __other) const
208 { return _M_off - __other._M_off; }
211 // The standard only requires that operator== must be an
212 // equivalence relation. In this implementation two fpos<StateT>
213 // objects belong to the same equivalence class if the contained
214 // offsets compare equal.
215 /// Test if equivalent to another position.
216 template<typename _StateT>
218 operator==(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
219 { return streamoff(__lhs) == streamoff(__rhs); }
221 template<typename _StateT>
223 operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
224 { return streamoff(__lhs) != streamoff(__rhs); }
226 // Clauses 21.1.3.1 and 21.1.3.2 describe streampos and wstreampos
227 // as implementation defined types, but clause 27.2 requires that
228 // they must both be typedefs for fpos<mbstate_t>
229 /// File position for char streams.
230 typedef fpos<mbstate_t> streampos;
231 /// File position for wchar_t streams.
232 typedef fpos<mbstate_t> wstreampos;
234 #ifdef __GXX_EXPERIMENTAL_CXX0X__
235 /// File position for char16_t streams.
236 typedef fpos<mbstate_t> u16streampos;
237 /// File position for char32_t streams.
238 typedef fpos<mbstate_t> u32streampos;
241 _GLIBCXX_END_NAMESPACE_VERSION