libstdc++
regex_constants.h
Go to the documentation of this file.
1 // Namespace std::regex_constants -*- C++ -*-
2 
3 // Copyright (C) 2010-2023 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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /**
26  * @file bits/regex_constants.h
27  * @brief Constant definitions for the std regex library.
28  *
29  * This is an internal header file, included by other library headers.
30  * Do not attempt to use it directly. @headername{regex}
31  */
32 
33 namespace std _GLIBCXX_VISIBILITY(default)
34 {
35 _GLIBCXX_BEGIN_NAMESPACE_VERSION
36 
37 /**
38  * @defgroup regex Regular Expressions
39  *
40  * A facility for performing regular expression pattern matching.
41  *
42  * @since C++11
43  *
44  * @{
45  */
46 
47 /**
48  * @namespace std::regex_constants
49  * @brief ISO C++ 2011 namespace for options and flags used with std::regex
50  */
51 namespace regex_constants
52 {
53  /**
54  * @name 5.1 Regular Expression Syntax Options
55  */
56  ///@{
57 
58  /**
59  * @brief This is a bitmask type indicating how to interpret the regex.
60  *
61  * The @c syntax_option_type is implementation defined but it is valid to
62  * perform bitwise operations on these values and expect the right thing to
63  * happen.
64  *
65  * A valid value of type syntax_option_type shall have exactly one of the
66  * elements @c ECMAScript, @c basic, @c extended, @c awk, @c grep, @c egrep
67  * %set.
68  */
69  enum syntax_option_type : unsigned int
70  {
71  _S_icase = 1 << 0,
72  _S_nosubs = 1 << 1,
73  _S_optimize = 1 << 2,
74  _S_collate = 1 << 3,
75  _S_ECMAScript = 1 << 4,
76  _S_basic = 1 << 5,
77  _S_extended = 1 << 6,
78  _S_awk = 1 << 7,
79  _S_grep = 1 << 8,
80  _S_egrep = 1 << 9,
81  _S_polynomial = 1 << 10,
82  _S_multiline = 1 << 11
83  };
84 
85  /**
86  * Specifies that the matching of regular expressions against a character
87  * sequence shall be performed without regard to case.
88  */
89  _GLIBCXX17_INLINE constexpr syntax_option_type icase = _S_icase;
90 
91  /**
92  * Specifies that when a regular expression is matched against a character
93  * container sequence, no sub-expression matches are to be stored in the
94  * supplied match_results structure.
95  */
96  _GLIBCXX17_INLINE constexpr syntax_option_type nosubs = _S_nosubs;
97 
98  /**
99  * Specifies that the regular expression engine should pay more attention to
100  * the speed with which regular expressions are matched, and less to the
101  * speed with which regular expression objects are constructed. Otherwise
102  * it has no detectable effect on the program output.
103  */
104  _GLIBCXX17_INLINE constexpr syntax_option_type optimize = _S_optimize;
105 
106  /**
107  * Specifies that character ranges of the form [a-b] should be locale
108  * sensitive.
109  */
110  _GLIBCXX17_INLINE constexpr syntax_option_type collate = _S_collate;
111 
112  /**
113  * Specifies that the grammar recognized by the regular expression engine is
114  * that used by ECMAScript in ECMA-262 [Ecma International, ECMAScript
115  * Language Specification, Standard Ecma-262, third edition, 1999], as
116  * modified in section [28.13]. This grammar is similar to that defined
117  * in the PERL scripting language but extended with elements found in the
118  * POSIX regular expression grammar.
119  */
120  _GLIBCXX17_INLINE constexpr syntax_option_type ECMAScript = _S_ECMAScript;
121 
122  /**
123  * Specifies that the grammar recognized by the regular expression engine is
124  * that used by POSIX basic regular expressions in IEEE Std 1003.1-2001,
125  * Portable Operating System Interface (POSIX), Base Definitions and
126  * Headers, Section 9, Regular Expressions [IEEE, Information Technology --
127  * Portable Operating System Interface (POSIX), IEEE Standard 1003.1-2001].
128  */
129  _GLIBCXX17_INLINE constexpr syntax_option_type basic = _S_basic;
130 
131  /**
132  * Specifies that the grammar recognized by the regular expression engine is
133  * that used by POSIX extended regular expressions in IEEE Std 1003.1-2001,
134  * Portable Operating System Interface (POSIX), Base Definitions and
135  * Headers, Section 9, Regular Expressions.
136  */
137  _GLIBCXX17_INLINE constexpr syntax_option_type extended = _S_extended;
138 
139  /**
140  * Specifies that the grammar recognized by the regular expression engine is
141  * that used by POSIX utility awk in IEEE Std 1003.1-2001. This option is
142  * identical to syntax_option_type extended, except that C-style escape
143  * sequences are supported. These sequences are:
144  * \\\\, \\a, \\b, \\f, \\n, \\r, \\t , \\v, \\&apos,, &apos,,
145  * and \\ddd (where ddd is one, two, or three octal digits).
146  */
147  _GLIBCXX17_INLINE constexpr syntax_option_type awk = _S_awk;
148 
149  /**
150  * Specifies that the grammar recognized by the regular expression engine is
151  * that used by POSIX utility grep in IEEE Std 1003.1-2001. This option is
152  * identical to syntax_option_type basic, except that newlines are treated
153  * as whitespace.
154  */
155  _GLIBCXX17_INLINE constexpr syntax_option_type grep = _S_grep;
156 
157  /**
158  * Specifies that the grammar recognized by the regular expression engine is
159  * that used by POSIX utility grep when given the -E option in
160  * IEEE Std 1003.1-2001. This option is identical to syntax_option_type
161  * extended, except that newlines are treated as whitespace.
162  */
163  _GLIBCXX17_INLINE constexpr syntax_option_type egrep = _S_egrep;
164 
165 #if __cplusplus >= 201703L || !defined __STRICT_ANSI__
166  // _GLIBCXX_RESOLVE_LIB_DEFECTS
167  // 2503. multiline option should be added to syntax_option_type
168  /**
169  * Specifies that the `^` anchor matches at the beginning of a line,
170  * and the `$` anchor matches at the end of a line, not only at the
171  * beginning/end of the input.
172  * Valid for the ECMAScript syntax, ignored otherwise.
173  * @since C++17
174  */
175  _GLIBCXX17_INLINE constexpr syntax_option_type multiline = _S_multiline;
176 #endif
177 
178  /// Extension: Equivalent to regex_constants::multiline for C++11 and C++14.
179  _GLIBCXX17_INLINE constexpr syntax_option_type __multiline = _S_multiline;
180 
181  /**
182  * Extension: Ensure both space complexity of compiled regex and
183  * time complexity execution are not exponential.
184  * If specified in a regex with back-references, the exception
185  * regex_constants::error_complexity will be thrown.
186  */
187  _GLIBCXX17_INLINE constexpr syntax_option_type __polynomial = _S_polynomial;
188 
189  constexpr inline syntax_option_type
191  {
192  return (syntax_option_type)(static_cast<unsigned int>(__a)
193  & static_cast<unsigned int>(__b));
194  }
195 
196  constexpr inline syntax_option_type
198  {
199  return (syntax_option_type)(static_cast<unsigned int>(__a)
200  | static_cast<unsigned int>(__b));
201  }
202 
203  constexpr inline syntax_option_type
205  {
206  return (syntax_option_type)(static_cast<unsigned int>(__a)
207  ^ static_cast<unsigned int>(__b));
208  }
209 
210  constexpr inline syntax_option_type
212  { return (syntax_option_type)(~static_cast<unsigned int>(__a)); }
213 
214  _GLIBCXX14_CONSTEXPR
215  inline syntax_option_type&
217  { return __a = __a & __b; }
218 
219  _GLIBCXX14_CONSTEXPR
220  inline syntax_option_type&
222  { return __a = __a | __b; }
223 
224  _GLIBCXX14_CONSTEXPR
225  inline syntax_option_type&
227  { return __a = __a ^ __b; }
228 
229  ///@}
230 
231  /**
232  * @name 5.2 Matching Rules
233  *
234  * Matching a regular expression against a sequence of characters [first,
235  * last) proceeds according to the rules of the grammar specified for the
236  * regular expression object, modified according to the effects listed
237  * below for any bitmask elements set.
238  *
239  */
240  ///@{
241 
242  /**
243  * @brief This is a bitmask type indicating regex matching rules.
244  *
245  * The @c match_flag_type is implementation defined but it is valid to
246  * perform bitwise operations on these values and expect the right thing to
247  * happen.
248  */
249  enum match_flag_type : unsigned int
250  {
251  _S_default,
252  _S_not_bol = 1 << 0,
253  _S_not_eol = 1 << 1,
254  _S_not_bow = 1 << 2,
255  _S_not_eow = 1 << 3,
256  _S_any = 1 << 4,
257  _S_not_null = 1 << 5,
258  _S_continuous = 1 << 6,
259  _S_prev_avail = 1 << 7,
260  _S_sed = 1 << 8,
261  _S_no_copy = 1 << 9,
262  _S_first_only = 1 << 10,
263  _S_match_flag_last = 1 << 11
264  };
265 
266  /**
267  * The default matching rules.
268  */
269  _GLIBCXX17_INLINE constexpr match_flag_type match_default = _S_default;
270 
271  /**
272  * The first character in the sequence [first, last) is treated as though it
273  * is not at the beginning of a line, so the character (^) in the regular
274  * expression shall not match [first, first).
275  */
276  _GLIBCXX17_INLINE constexpr match_flag_type match_not_bol = _S_not_bol;
277 
278  /**
279  * The last character in the sequence [first, last) is treated as though it
280  * is not at the end of a line, so the character ($) in the regular
281  * expression shall not match [last, last).
282  */
283  _GLIBCXX17_INLINE constexpr match_flag_type match_not_eol = _S_not_eol;
284 
285  /**
286  * The expression \\b is not matched against the sub-sequence
287  * [first,first).
288  */
289  _GLIBCXX17_INLINE constexpr match_flag_type match_not_bow = _S_not_bow;
290 
291  /**
292  * The expression \\b should not be matched against the sub-sequence
293  * [last,last).
294  */
295  _GLIBCXX17_INLINE constexpr match_flag_type match_not_eow = _S_not_eow;
296 
297  /**
298  * If more than one match is possible then any match is an acceptable
299  * result.
300  */
301  _GLIBCXX17_INLINE constexpr match_flag_type match_any = _S_any;
302 
303  /**
304  * The expression does not match an empty sequence.
305  */
306  _GLIBCXX17_INLINE constexpr match_flag_type match_not_null = _S_not_null;
307 
308  /**
309  * The expression only matches a sub-sequence that begins at first .
310  */
311  _GLIBCXX17_INLINE constexpr match_flag_type match_continuous = _S_continuous;
312 
313  /**
314  * `--first` is a valid iterator position. When this flag is set then the
315  * flags `match_not_bol` and `match_not_bow` are ignored by the algorithms
316  * `regex_match`, `regex_search`, and `regex_replace`, and by the iterators
317  * `regex_iterator` and `regex_token_iterator`.
318  */
319  _GLIBCXX17_INLINE constexpr match_flag_type match_prev_avail = _S_prev_avail;
320 
321  /**
322  * When a regular expression match is to be replaced by a new string, the
323  * new string is constructed using the rules used by the ECMAScript replace
324  * function in ECMA- 262 [Ecma International, ECMAScript Language
325  * Specification, Standard Ecma-262, third edition, 1999], part 15.5.4.11
326  * String.prototype.replace. In addition, during search and replace
327  * operations all non-overlapping occurrences of the regular expression
328  * are located and replaced, and sections of the input that did not match
329  * the expression are copied unchanged to the output string.
330  *
331  * Format strings (from ECMA-262 [15.5.4.11]):
332  * @li $$ The dollar-sign itself ($)
333  * @li $& The matched substring.
334  * @li $` The portion of @a string that precedes the matched substring.
335  * This would be match_results::prefix().
336  * @li $' The portion of @a string that follows the matched substring.
337  * This would be match_results::suffix().
338  * @li $n The nth capture, where n is in [1,9] and $n is not followed by a
339  * decimal digit. If n <= match_results::size() and the nth capture
340  * is undefined, use the empty string instead. If n >
341  * match_results::size(), the result is implementation-defined.
342  * @li $nn The nnth capture, where nn is a two-digit decimal number on
343  * [01, 99]. If nn <= match_results::size() and the nth capture is
344  * undefined, use the empty string instead. If
345  * nn > match_results::size(), the result is implementation-defined.
346  */
347  _GLIBCXX17_INLINE constexpr match_flag_type format_default = _S_default;
348 
349  /**
350  * When a regular expression match is to be replaced by a new string, the
351  * new string is constructed using the rules used by the POSIX sed utility
352  * in IEEE Std 1003.1- 2001 [IEEE, Information Technology -- Portable
353  * Operating System Interface (POSIX), IEEE Standard 1003.1-2001].
354  */
355  _GLIBCXX17_INLINE constexpr match_flag_type format_sed = _S_sed;
356 
357  /**
358  * During a search and replace operation, sections of the character
359  * container sequence being searched that do not match the regular
360  * expression shall not be copied to the output string.
361  */
362  _GLIBCXX17_INLINE constexpr match_flag_type format_no_copy = _S_no_copy;
363 
364  /**
365  * When specified during a search and replace operation, only the first
366  * occurrence of the regular expression shall be replaced.
367  */
368  _GLIBCXX17_INLINE constexpr match_flag_type format_first_only = _S_first_only;
369 
370  constexpr inline match_flag_type
372  {
373  return (match_flag_type)(static_cast<unsigned int>(__a)
374  & static_cast<unsigned int>(__b));
375  }
376 
377  constexpr inline match_flag_type
379  {
380  return (match_flag_type)(static_cast<unsigned int>(__a)
381  | static_cast<unsigned int>(__b));
382  }
383 
384  constexpr inline match_flag_type
386  {
387  return (match_flag_type)(static_cast<unsigned int>(__a)
388  ^ static_cast<unsigned int>(__b));
389  }
390 
391  constexpr inline match_flag_type
393  { return (match_flag_type)(~static_cast<unsigned int>(__a)); }
394 
395  _GLIBCXX14_CONSTEXPR
396  inline match_flag_type&
398  { return __a = __a & __b; }
399 
400  _GLIBCXX14_CONSTEXPR
401  inline match_flag_type&
403  { return __a = __a | __b; }
404 
405  _GLIBCXX14_CONSTEXPR
406  inline match_flag_type&
408  { return __a = __a ^ __b; }
409 
410  ///@}
411 } // namespace regex_constants
412 /// @} group regex
413 
414 _GLIBCXX_END_NAMESPACE_VERSION
415 } // namespace std
416 
std::regex_constants::grep
constexpr syntax_option_type grep
Definition: regex_constants.h:155
std::regex_constants::match_default
constexpr match_flag_type match_default
Definition: regex_constants.h:269
std::regex_constants::__multiline
constexpr syntax_option_type __multiline
Extension: Equivalent to regex_constants::multiline for C++11 and C++14.
Definition: regex_constants.h:179
std::regex_constants::extended
constexpr syntax_option_type extended
Definition: regex_constants.h:137
std::collate
Facet for localized string comparison.
Definition: locale_classes.h:660
std::regex_constants::match_not_eow
constexpr match_flag_type match_not_eow
Definition: regex_constants.h:295
std::regex_constants::optimize
constexpr syntax_option_type optimize
Definition: regex_constants.h:104
std::regex_constants::operator|=
constexpr syntax_option_type & operator|=(syntax_option_type &__a, syntax_option_type __b)
This is a bitmask type indicating how to interpret the regex.
Definition: regex_constants.h:221
std::regex_constants::operator~
constexpr syntax_option_type operator~(syntax_option_type __a)
This is a bitmask type indicating how to interpret the regex.
Definition: regex_constants.h:211
std::regex_constants::basic
constexpr syntax_option_type basic
Definition: regex_constants.h:129
std::regex_constants::operator|
constexpr syntax_option_type operator|(syntax_option_type __a, syntax_option_type __b)
This is a bitmask type indicating how to interpret the regex.
Definition: regex_constants.h:197
std::regex_constants::operator&=
constexpr syntax_option_type & operator&=(syntax_option_type &__a, syntax_option_type __b)
This is a bitmask type indicating how to interpret the regex.
Definition: regex_constants.h:216
std::regex_constants::syntax_option_type
syntax_option_type
This is a bitmask type indicating how to interpret the regex.
Definition: regex_constants.h:69
std::regex_constants::format_first_only
constexpr match_flag_type format_first_only
Definition: regex_constants.h:368
std::regex_constants::awk
constexpr syntax_option_type awk
Definition: regex_constants.h:147
std::regex_constants::icase
constexpr syntax_option_type icase
Definition: regex_constants.h:89
std::regex_constants::match_any
constexpr match_flag_type match_any
Definition: regex_constants.h:301
std::regex_constants::egrep
constexpr syntax_option_type egrep
Definition: regex_constants.h:163
std::regex_constants::format_no_copy
constexpr match_flag_type format_no_copy
Definition: regex_constants.h:362
std::regex_constants::match_not_null
constexpr match_flag_type match_not_null
Definition: regex_constants.h:306
std::regex_constants::nosubs
constexpr syntax_option_type nosubs
Definition: regex_constants.h:96
std::regex_constants::format_default
constexpr match_flag_type format_default
Definition: regex_constants.h:347
std::regex_constants::ECMAScript
constexpr syntax_option_type ECMAScript
Definition: regex_constants.h:120
std::regex_constants::match_prev_avail
constexpr match_flag_type match_prev_avail
Definition: regex_constants.h:319
std::regex_constants::match_flag_type
match_flag_type
This is a bitmask type indicating regex matching rules.
Definition: regex_constants.h:249
std::regex_constants::match_not_bol
constexpr match_flag_type match_not_bol
Definition: regex_constants.h:276
std::regex_constants::match_continuous
constexpr match_flag_type match_continuous
Definition: regex_constants.h:311
std::regex_constants::multiline
constexpr syntax_option_type multiline
Definition: regex_constants.h:175
std
ISO C++ entities toplevel namespace is std.
std::regex_constants::operator&
constexpr syntax_option_type operator&(syntax_option_type __a, syntax_option_type __b)
This is a bitmask type indicating how to interpret the regex.
Definition: regex_constants.h:190
std::regex_constants::operator^
constexpr syntax_option_type operator^(syntax_option_type __a, syntax_option_type __b)
This is a bitmask type indicating how to interpret the regex.
Definition: regex_constants.h:204
std::regex_constants::match_not_eol
constexpr match_flag_type match_not_eol
Definition: regex_constants.h:283
std::regex_constants::format_sed
constexpr match_flag_type format_sed
Definition: regex_constants.h:355
std::regex_constants::match_not_bow
constexpr match_flag_type match_not_bow
Definition: regex_constants.h:289
std::regex_constants::operator^=
constexpr syntax_option_type & operator^=(syntax_option_type &__a, syntax_option_type __b)
This is a bitmask type indicating how to interpret the regex.
Definition: regex_constants.h:226
std::regex_constants::__polynomial
constexpr syntax_option_type __polynomial
Definition: regex_constants.h:187