Bug Summary

File:clang-tools-extra/clang-tidy/readability/RedundantControlFlowCheck.cpp
Warning:line 82, column 9
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name RedundantControlFlowCheck.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -relaxed-aliasing -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/build-llvm/tools/clang/stage2-bins -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I tools/clang/tools/extra/clang-tidy/readability -I /build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/clang-tools-extra/clang-tidy/readability -I tools/clang/tools/extra/clang-tidy -I /build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/clang/include -I tools/clang/include -I include -I /build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/llvm/include -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fmacro-prefix-map=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/= -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/= -O3 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2022-01-19-134126-35450-1 -x c++ /build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/clang-tools-extra/clang-tidy/readability/RedundantControlFlowCheck.cpp

/build/llvm-toolchain-snapshot-14~++20220119111520+da61cb019eb2/clang-tools-extra/clang-tidy/readability/RedundantControlFlowCheck.cpp

1//===--- RedundantControlFlowCheck.cpp - clang-tidy------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "RedundantControlFlowCheck.h"
10#include "clang/AST/ASTContext.h"
11#include "clang/ASTMatchers/ASTMatchFinder.h"
12#include "clang/Lex/Lexer.h"
13
14using namespace clang::ast_matchers;
15
16namespace clang {
17namespace tidy {
18namespace readability {
19
20namespace {
21
22const char *const RedundantReturnDiag = "redundant return statement at the end "
23 "of a function with a void return type";
24const char *const RedundantContinueDiag = "redundant continue statement at the "
25 "end of loop statement";
26
27bool isLocationInMacroExpansion(const SourceManager &SM, SourceLocation Loc) {
28 return SM.isMacroBodyExpansion(Loc) || SM.isMacroArgExpansion(Loc);
7
Assuming the condition is false
8
Returning value, which participates in a condition later
29}
30
31} // namespace
32
33void RedundantControlFlowCheck::registerMatchers(MatchFinder *Finder) {
34 Finder->addMatcher(
35 functionDecl(isDefinition(), returns(voidType()),
36 hasBody(compoundStmt(hasAnySubstatement(
37 returnStmt(unless(has(expr())))))
38 .bind("return"))),
39 this);
40 Finder->addMatcher(
41 mapAnyOf(forStmt, cxxForRangeStmt, whileStmt, doStmt)
42 .with(hasBody(compoundStmt(hasAnySubstatement(continueStmt()))
43 .bind("continue"))),
44 this);
45}
46
47void RedundantControlFlowCheck::check(const MatchFinder::MatchResult &Result) {
48 if (const auto *Return
0.1
'Return' is non-null
0.1
'Return' is non-null
= Result.Nodes.getNodeAs<CompoundStmt>("return"))
1
Taking true branch
49 checkRedundantReturn(Result, Return);
2
Calling 'RedundantControlFlowCheck::checkRedundantReturn'
50 else if (const auto *Continue =
51 Result.Nodes.getNodeAs<CompoundStmt>("continue"))
52 checkRedundantContinue(Result, Continue);
53}
54
55void RedundantControlFlowCheck::checkRedundantReturn(
56 const MatchFinder::MatchResult &Result, const CompoundStmt *Block) {
57 CompoundStmt::const_reverse_body_iterator Last = Block->body_rbegin();
58 if (const auto *Return
3.1
'Return' is non-null
3.1
'Return' is non-null
= dyn_cast<ReturnStmt>(*Last))
3
Assuming the object is a 'ReturnStmt'
4
Taking true branch
59 issueDiagnostic(Result, Block, Return->getSourceRange(),
5
Calling 'RedundantControlFlowCheck::issueDiagnostic'
60 RedundantReturnDiag);
61}
62
63void RedundantControlFlowCheck::checkRedundantContinue(
64 const MatchFinder::MatchResult &Result, const CompoundStmt *Block) {
65 CompoundStmt::const_reverse_body_iterator Last = Block->body_rbegin();
66 if (const auto *Continue = dyn_cast<ContinueStmt>(*Last))
67 issueDiagnostic(Result, Block, Continue->getSourceRange(),
68 RedundantContinueDiag);
69}
70
71void RedundantControlFlowCheck::issueDiagnostic(
72 const MatchFinder::MatchResult &Result, const CompoundStmt *const Block,
73 const SourceRange &StmtRange, const char *const Diag) {
74 SourceManager &SM = *Result.SourceManager;
75 if (isLocationInMacroExpansion(SM, StmtRange.getBegin()))
6
Calling 'isLocationInMacroExpansion'
9
Returning from 'isLocationInMacroExpansion'
10
Assuming the condition is false
11
Taking false branch
76 return;
77
78 CompoundStmt::const_reverse_body_iterator Previous = ++Block->body_rbegin();
79 SourceLocation Start;
80 if (Previous != Block->body_rend())
12
Calling 'operator!=<clang::Stmt *const *>'
18
Returning from 'operator!=<clang::Stmt *const *>'
19
Taking true branch
81 Start = Lexer::findLocationAfterToken(
82 dyn_cast<Stmt>(*Previous)->getEndLoc(), tok::semi, SM, getLangOpts(),
20
Assuming the object is not a 'Stmt'
21
Called C++ object pointer is null
83 /*SkipTrailingWhitespaceAndNewLine=*/true);
84 if (!Start.isValid())
85 Start = StmtRange.getBegin();
86 auto RemovedRange = CharSourceRange::getCharRange(
87 Start, Lexer::findLocationAfterToken(
88 StmtRange.getEnd(), tok::semi, SM, getLangOpts(),
89 /*SkipTrailingWhitespaceAndNewLine=*/true));
90
91 diag(StmtRange.getBegin(), Diag) << FixItHint::CreateRemoval(RemovedRange);
92}
93
94} // namespace readability
95} // namespace tidy
96} // namespace clang

/usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/stl_iterator.h

1// Iterators -*- C++ -*-
2
3// Copyright (C) 2001-2020 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 *
27 * Copyright (c) 1994
28 * Hewlett-Packard Company
29 *
30 * Permission to use, copy, modify, distribute and sell this software
31 * and its documentation for any purpose is hereby granted without fee,
32 * provided that the above copyright notice appear in all copies and
33 * that both that copyright notice and this permission notice appear
34 * in supporting documentation. Hewlett-Packard Company makes no
35 * representations about the suitability of this software for any
36 * purpose. It is provided "as is" without express or implied warranty.
37 *
38 *
39 * Copyright (c) 1996-1998
40 * Silicon Graphics Computer Systems, Inc.
41 *
42 * Permission to use, copy, modify, distribute and sell this software
43 * and its documentation for any purpose is hereby granted without fee,
44 * provided that the above copyright notice appear in all copies and
45 * that both that copyright notice and this permission notice appear
46 * in supporting documentation. Silicon Graphics makes no
47 * representations about the suitability of this software for any
48 * purpose. It is provided "as is" without express or implied warranty.
49 */
50
51/** @file bits/stl_iterator.h
52 * This is an internal header file, included by other library headers.
53 * Do not attempt to use it directly. @headername{iterator}
54 *
55 * This file implements reverse_iterator, back_insert_iterator,
56 * front_insert_iterator, insert_iterator, __normal_iterator, and their
57 * supporting functions and overloaded operators.
58 */
59
60#ifndef _STL_ITERATOR_H1
61#define _STL_ITERATOR_H1 1
62
63#include <bits/cpp_type_traits.h>
64#include <ext/type_traits.h>
65#include <bits/move.h>
66#include <bits/ptr_traits.h>
67
68#if __cplusplus201402L >= 201103L
69# include <type_traits>
70#endif
71
72#if __cplusplus201402L > 201703L
73# define __cpp_lib_array_constexpr 201811L
74# define __cpp_lib_constexpr_iterator 201811L
75#elif __cplusplus201402L == 201703L
76# define __cpp_lib_array_constexpr 201803L
77#endif
78
79#if __cplusplus201402L > 201703L
80# include <compare>
81# include <new>
82# include <bits/iterator_concepts.h>
83#endif
84
85namespace std _GLIBCXX_VISIBILITY(default)__attribute__ ((__visibility__ ("default")))
86{
87_GLIBCXX_BEGIN_NAMESPACE_VERSION
88
89 /**
90 * @addtogroup iterators
91 * @{
92 */
93
94#if __cplusplus201402L > 201703L && __cpp_lib_concepts
95 namespace __detail
96 {
97 // Weaken iterator_category _Cat to _Limit if it is derived from that,
98 // otherwise use _Otherwise.
99 template<typename _Cat, typename _Limit, typename _Otherwise = _Cat>
100 using __clamp_iter_cat
101 = conditional_t<derived_from<_Cat, _Limit>, _Limit, _Otherwise>;
102 }
103#endif
104
105 // 24.4.1 Reverse iterators
106 /**
107 * Bidirectional and random access iterators have corresponding reverse
108 * %iterator adaptors that iterate through the data structure in the
109 * opposite direction. They have the same signatures as the corresponding
110 * iterators. The fundamental relation between a reverse %iterator and its
111 * corresponding %iterator @c i is established by the identity:
112 * @code
113 * &*(reverse_iterator(i)) == &*(i - 1)
114 * @endcode
115 *
116 * <em>This mapping is dictated by the fact that while there is always a
117 * pointer past the end of an array, there might not be a valid pointer
118 * before the beginning of an array.</em> [24.4.1]/1,2
119 *
120 * Reverse iterators can be tricky and surprising at first. Their
121 * semantics make sense, however, and the trickiness is a side effect of
122 * the requirement that the iterators must be safe.
123 */
124 template<typename _Iterator>
125 class reverse_iterator
126 : public iterator<typename iterator_traits<_Iterator>::iterator_category,
127 typename iterator_traits<_Iterator>::value_type,
128 typename iterator_traits<_Iterator>::difference_type,
129 typename iterator_traits<_Iterator>::pointer,
130 typename iterator_traits<_Iterator>::reference>
131 {
132 protected:
133 _Iterator current;
134
135 typedef iterator_traits<_Iterator> __traits_type;
136
137 public:
138 typedef _Iterator iterator_type;
139 typedef typename __traits_type::difference_type difference_type;
140 typedef typename __traits_type::pointer pointer;
141 typedef typename __traits_type::reference reference;
142
143#if __cplusplus201402L > 201703L && __cpp_lib_concepts
144 using iterator_concept
145 = conditional_t<random_access_iterator<_Iterator>,
146 random_access_iterator_tag,
147 bidirectional_iterator_tag>;
148 using iterator_category
149 = __detail::__clamp_iter_cat<typename __traits_type::iterator_category,
150 random_access_iterator_tag>;
151#endif
152
153 /**
154 * The default constructor value-initializes member @p current.
155 * If it is a pointer, that means it is zero-initialized.
156 */
157 // _GLIBCXX_RESOLVE_LIB_DEFECTS
158 // 235 No specification of default ctor for reverse_iterator
159 // 1012. reverse_iterator default ctor should value initialize
160 _GLIBCXX17_CONSTEXPR
161 reverse_iterator() : current() { }
162
163 /**
164 * This %iterator will move in the opposite direction that @p x does.
165 */
166 explicit _GLIBCXX17_CONSTEXPR
167 reverse_iterator(iterator_type __x) : current(__x) { }
168
169 /**
170 * The copy constructor is normal.
171 */
172 _GLIBCXX17_CONSTEXPR
173 reverse_iterator(const reverse_iterator& __x)
174 : current(__x.current) { }
175
176#if __cplusplus201402L >= 201103L
177 reverse_iterator& operator=(const reverse_iterator&) = default;
178#endif
179
180 /**
181 * A %reverse_iterator across other types can be copied if the
182 * underlying %iterator can be converted to the type of @c current.
183 */
184 template<typename _Iter>
185 _GLIBCXX17_CONSTEXPR
186 reverse_iterator(const reverse_iterator<_Iter>& __x)
187 : current(__x.base()) { }
188
189 /**
190 * @return @c current, the %iterator used for underlying work.
191 */
192 _GLIBCXX17_CONSTEXPR iterator_type
193 base() const
194 { return current; }
195
196 /**
197 * @return A reference to the value at @c --current
198 *
199 * This requires that @c --current is dereferenceable.
200 *
201 * @warning This implementation requires that for an iterator of the
202 * underlying iterator type, @c x, a reference obtained by
203 * @c *x remains valid after @c x has been modified or
204 * destroyed. This is a bug: http://gcc.gnu.org/PR51823
205 */
206 _GLIBCXX17_CONSTEXPR reference
207 operator*() const
208 {
209 _Iterator __tmp = current;
210 return *--__tmp;
211 }
212
213 /**
214 * @return A pointer to the value at @c --current
215 *
216 * This requires that @c --current is dereferenceable.
217 */
218 _GLIBCXX17_CONSTEXPR pointer
219 operator->() const
220#if __cplusplus201402L > 201703L && __cpp_concepts >= 201907L
221 requires is_pointer_v<_Iterator>
222 || requires(const _Iterator __i) { __i.operator->(); }
223#endif
224 {
225 // _GLIBCXX_RESOLVE_LIB_DEFECTS
226 // 1052. operator-> should also support smart pointers
227 _Iterator __tmp = current;
228 --__tmp;
229 return _S_to_pointer(__tmp);
230 }
231
232 /**
233 * @return @c *this
234 *
235 * Decrements the underlying iterator.
236 */
237 _GLIBCXX17_CONSTEXPR reverse_iterator&
238 operator++()
239 {
240 --current;
241 return *this;
242 }
243
244 /**
245 * @return The original value of @c *this
246 *
247 * Decrements the underlying iterator.
248 */
249 _GLIBCXX17_CONSTEXPR reverse_iterator
250 operator++(int)
251 {
252 reverse_iterator __tmp = *this;
253 --current;
254 return __tmp;
255 }
256
257 /**
258 * @return @c *this
259 *
260 * Increments the underlying iterator.
261 */
262 _GLIBCXX17_CONSTEXPR reverse_iterator&
263 operator--()
264 {
265 ++current;
266 return *this;
267 }
268
269 /**
270 * @return A reverse_iterator with the previous value of @c *this
271 *
272 * Increments the underlying iterator.
273 */
274 _GLIBCXX17_CONSTEXPR reverse_iterator
275 operator--(int)
276 {
277 reverse_iterator __tmp = *this;
278 ++current;
279 return __tmp;
280 }
281
282 /**
283 * @return A reverse_iterator that refers to @c current - @a __n
284 *
285 * The underlying iterator must be a Random Access Iterator.
286 */
287 _GLIBCXX17_CONSTEXPR reverse_iterator
288 operator+(difference_type __n) const
289 { return reverse_iterator(current - __n); }
290
291 /**
292 * @return *this
293 *
294 * Moves the underlying iterator backwards @a __n steps.
295 * The underlying iterator must be a Random Access Iterator.
296 */
297 _GLIBCXX17_CONSTEXPR reverse_iterator&
298 operator+=(difference_type __n)
299 {
300 current -= __n;
301 return *this;
302 }
303
304 /**
305 * @return A reverse_iterator that refers to @c current - @a __n
306 *
307 * The underlying iterator must be a Random Access Iterator.
308 */
309 _GLIBCXX17_CONSTEXPR reverse_iterator
310 operator-(difference_type __n) const
311 { return reverse_iterator(current + __n); }
312
313 /**
314 * @return *this
315 *
316 * Moves the underlying iterator forwards @a __n steps.
317 * The underlying iterator must be a Random Access Iterator.
318 */
319 _GLIBCXX17_CONSTEXPR reverse_iterator&
320 operator-=(difference_type __n)
321 {
322 current += __n;
323 return *this;
324 }
325
326 /**
327 * @return The value at @c current - @a __n - 1
328 *
329 * The underlying iterator must be a Random Access Iterator.
330 */
331 _GLIBCXX17_CONSTEXPR reference
332 operator[](difference_type __n) const
333 { return *(*this + __n); }
334
335#if __cplusplus201402L > 201703L && __cpp_lib_concepts
336 friend constexpr iter_rvalue_reference_t<_Iterator>
337 iter_move(const reverse_iterator& __i)
338 noexcept(is_nothrow_copy_constructible_v<_Iterator>
339 && noexcept(ranges::iter_move(--std::declval<_Iterator&>())))
340 {
341 auto __tmp = __i.base();
342 return ranges::iter_move(--__tmp);
343 }
344
345 template<indirectly_swappable<_Iterator> _Iter2>
346 friend constexpr void
347 iter_swap(const reverse_iterator& __x,
348 const reverse_iterator<_Iter2>& __y)
349 noexcept(is_nothrow_copy_constructible_v<_Iterator>
350 && is_nothrow_copy_constructible_v<_Iter2>
351 && noexcept(ranges::iter_swap(--std::declval<_Iterator&>(),
352 --std::declval<_Iter2&>())))
353 {
354 auto __xtmp = __x.base();
355 auto __ytmp = __y.base();
356 ranges::iter_swap(--__xtmp, --__ytmp);
357 }
358#endif
359
360 private:
361 template<typename _Tp>
362 static _GLIBCXX17_CONSTEXPR _Tp*
363 _S_to_pointer(_Tp* __p)
364 { return __p; }
365
366 template<typename _Tp>
367 static _GLIBCXX17_CONSTEXPR pointer
368 _S_to_pointer(_Tp __t)
369 { return __t.operator->(); }
370 };
371
372 //@{
373 /**
374 * @param __x A %reverse_iterator.
375 * @param __y A %reverse_iterator.
376 * @return A simple bool.
377 *
378 * Reverse iterators forward comparisons to their underlying base()
379 * iterators.
380 *
381 */
382#if __cplusplus201402L <= 201703L || ! defined __cpp_lib_concepts
383 template<typename _Iterator>
384 inline _GLIBCXX17_CONSTEXPR bool
385 operator==(const reverse_iterator<_Iterator>& __x,
386 const reverse_iterator<_Iterator>& __y)
387 { return __x.base() == __y.base(); }
14
Assuming the condition is false
15
Returning zero, which participates in a condition later
388
389 template<typename _Iterator>
390 inline _GLIBCXX17_CONSTEXPR bool
391 operator<(const reverse_iterator<_Iterator>& __x,
392 const reverse_iterator<_Iterator>& __y)
393 { return __y.base() < __x.base(); }
394
395 template<typename _Iterator>
396 inline _GLIBCXX17_CONSTEXPR bool
397 operator!=(const reverse_iterator<_Iterator>& __x,
398 const reverse_iterator<_Iterator>& __y)
399 { return !(__x == __y); }
13
Calling 'operator==<clang::Stmt *const *>'
16
Returning from 'operator==<clang::Stmt *const *>'
17
Returning the value 1, which participates in a condition later
400
401 template<typename _Iterator>
402 inline _GLIBCXX17_CONSTEXPR bool
403 operator>(const reverse_iterator<_Iterator>& __x,
404 const reverse_iterator<_Iterator>& __y)
405 { return __y < __x; }
406
407 template<typename _Iterator>
408 inline _GLIBCXX17_CONSTEXPR bool
409 operator<=(const reverse_iterator<_Iterator>& __x,
410 const reverse_iterator<_Iterator>& __y)
411 { return !(__y < __x); }
412
413 template<typename _Iterator>
414 inline _GLIBCXX17_CONSTEXPR bool
415 operator>=(const reverse_iterator<_Iterator>& __x,
416 const reverse_iterator<_Iterator>& __y)
417 { return !(__x < __y); }
418
419 // _GLIBCXX_RESOLVE_LIB_DEFECTS
420 // DR 280. Comparison of reverse_iterator to const reverse_iterator.
421 template<typename _IteratorL, typename _IteratorR>
422 inline _GLIBCXX17_CONSTEXPR bool
423 operator==(const reverse_iterator<_IteratorL>& __x,
424 const reverse_iterator<_IteratorR>& __y)
425 { return __x.base() == __y.base(); }
426
427 template<typename _IteratorL, typename _IteratorR>
428 inline _GLIBCXX17_CONSTEXPR bool
429 operator<(const reverse_iterator<_IteratorL>& __x,
430 const reverse_iterator<_IteratorR>& __y)
431 { return __y.base() < __x.base(); }
432
433 template<typename _IteratorL, typename _IteratorR>
434 inline _GLIBCXX17_CONSTEXPR bool
435 operator!=(const reverse_iterator<_IteratorL>& __x,
436 const reverse_iterator<_IteratorR>& __y)
437 { return !(__x == __y); }
438
439 template<typename _IteratorL, typename _IteratorR>
440 inline _GLIBCXX17_CONSTEXPR bool
441 operator>(const reverse_iterator<_IteratorL>& __x,
442 const reverse_iterator<_IteratorR>& __y)
443 { return __y < __x; }
444
445 template<typename _IteratorL, typename _IteratorR>
446 inline _GLIBCXX17_CONSTEXPR bool
447 operator<=(const reverse_iterator<_IteratorL>& __x,
448 const reverse_iterator<_IteratorR>& __y)
449 { return !(__y < __x); }
450
451 template<typename _IteratorL, typename _IteratorR>
452 inline _GLIBCXX17_CONSTEXPR bool
453 operator>=(const reverse_iterator<_IteratorL>& __x,
454 const reverse_iterator<_IteratorR>& __y)
455 { return !(__x < __y); }
456#else // C++20
457 template<typename _IteratorL, typename _IteratorR>
458 constexpr bool
459 operator==(const reverse_iterator<_IteratorL>& __x,
460 const reverse_iterator<_IteratorR>& __y)
461 requires requires { { __x.base() == __y.base() } -> convertible_to<bool>; }
462 { return __x.base() == __y.base(); }
463
464 template<typename _IteratorL, typename _IteratorR>
465 constexpr bool
466 operator!=(const reverse_iterator<_IteratorL>& __x,
467 const reverse_iterator<_IteratorR>& __y)
468 requires requires { { __x.base() != __y.base() } -> convertible_to<bool>; }
469 { return __x.base() != __y.base(); }
470
471 template<typename _IteratorL, typename _IteratorR>
472 constexpr bool
473 operator<(const reverse_iterator<_IteratorL>& __x,
474 const reverse_iterator<_IteratorR>& __y)
475 requires requires { { __x.base() > __y.base() } -> convertible_to<bool>; }
476 { return __x.base() > __y.base(); }
477
478 template<typename _IteratorL, typename _IteratorR>
479 constexpr bool
480 operator>(const reverse_iterator<_IteratorL>& __x,
481 const reverse_iterator<_IteratorR>& __y)
482 requires requires { { __x.base() < __y.base() } -> convertible_to<bool>; }
483 { return __x.base() < __y.base(); }
484
485 template<typename _IteratorL, typename _IteratorR>
486 constexpr bool
487 operator<=(const reverse_iterator<_IteratorL>& __x,
488 const reverse_iterator<_IteratorR>& __y)
489 requires requires { { __x.base() >= __y.base() } -> convertible_to<bool>; }
490 { return __x.base() >= __y.base(); }
491
492 template<typename _IteratorL, typename _IteratorR>
493 constexpr bool
494 operator>=(const reverse_iterator<_IteratorL>& __x,
495 const reverse_iterator<_IteratorR>& __y)
496 requires requires { { __x.base() <= __y.base() } -> convertible_to<bool>; }
497 { return __x.base() <= __y.base(); }
498
499 template<typename _IteratorL,
500 three_way_comparable_with<_IteratorL> _IteratorR>
501 constexpr compare_three_way_result_t<_IteratorL, _IteratorR>
502 operator<=>(const reverse_iterator<_IteratorL>& __x,
503 const reverse_iterator<_IteratorR>& __y)
504 { return __y.base() <=> __x.base(); }
505#endif // C++20
506 //@}
507
508#if __cplusplus201402L < 201103L
509 template<typename _Iterator>
510 inline typename reverse_iterator<_Iterator>::difference_type
511 operator-(const reverse_iterator<_Iterator>& __x,
512 const reverse_iterator<_Iterator>& __y)
513 { return __y.base() - __x.base(); }
514
515 template<typename _IteratorL, typename _IteratorR>
516 inline typename reverse_iterator<_IteratorL>::difference_type
517 operator-(const reverse_iterator<_IteratorL>& __x,
518 const reverse_iterator<_IteratorR>& __y)
519 { return __y.base() - __x.base(); }
520#else
521 // _GLIBCXX_RESOLVE_LIB_DEFECTS
522 // DR 685. reverse_iterator/move_iterator difference has invalid signatures
523 template<typename _IteratorL, typename _IteratorR>
524 inline _GLIBCXX17_CONSTEXPR auto
525 operator-(const reverse_iterator<_IteratorL>& __x,
526 const reverse_iterator<_IteratorR>& __y)
527 -> decltype(__y.base() - __x.base())
528 { return __y.base() - __x.base(); }
529#endif
530
531 template<typename _Iterator>
532 inline _GLIBCXX17_CONSTEXPR reverse_iterator<_Iterator>
533 operator+(typename reverse_iterator<_Iterator>::difference_type __n,
534 const reverse_iterator<_Iterator>& __x)
535 { return reverse_iterator<_Iterator>(__x.base() - __n); }
536
537#if __cplusplus201402L >= 201103L
538 // Same as C++14 make_reverse_iterator but used in C++11 mode too.
539 template<typename _Iterator>
540 inline _GLIBCXX17_CONSTEXPR reverse_iterator<_Iterator>
541 __make_reverse_iterator(_Iterator __i)
542 { return reverse_iterator<_Iterator>(__i); }
543
544# if __cplusplus201402L >= 201402L
545# define __cpp_lib_make_reverse_iterator201402 201402
546
547 // _GLIBCXX_RESOLVE_LIB_DEFECTS
548 // DR 2285. make_reverse_iterator
549 /// Generator function for reverse_iterator.
550 template<typename _Iterator>
551 inline _GLIBCXX17_CONSTEXPR reverse_iterator<_Iterator>
552 make_reverse_iterator(_Iterator __i)
553 { return reverse_iterator<_Iterator>(__i); }
554
555# if __cplusplus201402L > 201703L && defined __cpp_lib_concepts
556 template<typename _Iterator1, typename _Iterator2>
557 requires (!sized_sentinel_for<_Iterator1, _Iterator2>)
558 inline constexpr bool
559 disable_sized_sentinel_for<reverse_iterator<_Iterator1>,
560 reverse_iterator<_Iterator2>> = true;
561# endif // C++20
562# endif // C++14
563
564 template<typename _Iterator>
565 _GLIBCXX20_CONSTEXPR
566 auto
567 __niter_base(reverse_iterator<_Iterator> __it)
568 -> decltype(__make_reverse_iterator(__niter_base(__it.base())))
569 { return __make_reverse_iterator(__niter_base(__it.base())); }
570
571 template<typename _Iterator>
572 struct __is_move_iterator<reverse_iterator<_Iterator> >
573 : __is_move_iterator<_Iterator>
574 { };
575
576 template<typename _Iterator>
577 _GLIBCXX20_CONSTEXPR
578 auto
579 __miter_base(reverse_iterator<_Iterator> __it)
580 -> decltype(__make_reverse_iterator(__miter_base(__it.base())))
581 { return __make_reverse_iterator(__miter_base(__it.base())); }
582#endif // C++11
583
584 // 24.4.2.2.1 back_insert_iterator
585 /**
586 * @brief Turns assignment into insertion.
587 *
588 * These are output iterators, constructed from a container-of-T.
589 * Assigning a T to the iterator appends it to the container using
590 * push_back.
591 *
592 * Tip: Using the back_inserter function to create these iterators can
593 * save typing.
594 */
595 template<typename _Container>
596 class back_insert_iterator
597 : public iterator<output_iterator_tag, void, void, void, void>
598 {
599 protected:
600 _Container* container;
601
602 public:
603 /// A nested typedef for the type of whatever container you used.
604 typedef _Container container_type;
605#if __cplusplus201402L > 201703L
606 using difference_type = ptrdiff_t;
607
608 constexpr back_insert_iterator() noexcept : container(nullptr) { }
609#endif
610
611 /// The only way to create this %iterator is with a container.
612 explicit _GLIBCXX20_CONSTEXPR
613 back_insert_iterator(_Container& __x)
614 : container(std::__addressof(__x)) { }
615
616 /**
617 * @param __value An instance of whatever type
618 * container_type::const_reference is; presumably a
619 * reference-to-const T for container<T>.
620 * @return This %iterator, for chained operations.
621 *
622 * This kind of %iterator doesn't really have a @a position in the
623 * container (you can think of the position as being permanently at
624 * the end, if you like). Assigning a value to the %iterator will
625 * always append the value to the end of the container.
626 */
627#if __cplusplus201402L < 201103L
628 back_insert_iterator&
629 operator=(typename _Container::const_reference __value)
630 {
631 container->push_back(__value);
632 return *this;
633 }
634#else
635 _GLIBCXX20_CONSTEXPR
636 back_insert_iterator&
637 operator=(const typename _Container::value_type& __value)
638 {
639 container->push_back(__value);
640 return *this;
641 }
642
643 _GLIBCXX20_CONSTEXPR
644 back_insert_iterator&
645 operator=(typename _Container::value_type&& __value)
646 {
647 container->push_back(std::move(__value));
648 return *this;
649 }
650#endif
651
652 /// Simply returns *this.
653 _GLIBCXX20_CONSTEXPR
654 back_insert_iterator&
655 operator*()
656 { return *this; }
657
658 /// Simply returns *this. (This %iterator does not @a move.)
659 _GLIBCXX20_CONSTEXPR
660 back_insert_iterator&
661 operator++()
662 { return *this; }
663
664 /// Simply returns *this. (This %iterator does not @a move.)
665 _GLIBCXX20_CONSTEXPR
666 back_insert_iterator
667 operator++(int)
668 { return *this; }
669 };
670
671 /**
672 * @param __x A container of arbitrary type.
673 * @return An instance of back_insert_iterator working on @p __x.
674 *
675 * This wrapper function helps in creating back_insert_iterator instances.
676 * Typing the name of the %iterator requires knowing the precise full
677 * type of the container, which can be tedious and impedes generic
678 * programming. Using this function lets you take advantage of automatic
679 * template parameter deduction, making the compiler match the correct
680 * types for you.
681 */
682 template<typename _Container>
683 _GLIBCXX20_CONSTEXPR
684 inline back_insert_iterator<_Container>
685 back_inserter(_Container& __x)
686 { return back_insert_iterator<_Container>(__x); }
687
688 /**
689 * @brief Turns assignment into insertion.
690 *
691 * These are output iterators, constructed from a container-of-T.
692 * Assigning a T to the iterator prepends it to the container using
693 * push_front.
694 *
695 * Tip: Using the front_inserter function to create these iterators can
696 * save typing.
697 */
698 template<typename _Container>
699 class front_insert_iterator
700 : public iterator<output_iterator_tag, void, void, void, void>
701 {
702 protected:
703 _Container* container;
704
705 public:
706 /// A nested typedef for the type of whatever container you used.
707 typedef _Container container_type;
708#if __cplusplus201402L > 201703L
709 using difference_type = ptrdiff_t;
710
711 constexpr front_insert_iterator() noexcept : container(nullptr) { }
712#endif
713
714 /// The only way to create this %iterator is with a container.
715 explicit _GLIBCXX20_CONSTEXPR
716 front_insert_iterator(_Container& __x)
717 : container(std::__addressof(__x)) { }
718
719 /**
720 * @param __value An instance of whatever type
721 * container_type::const_reference is; presumably a
722 * reference-to-const T for container<T>.
723 * @return This %iterator, for chained operations.
724 *
725 * This kind of %iterator doesn't really have a @a position in the
726 * container (you can think of the position as being permanently at
727 * the front, if you like). Assigning a value to the %iterator will
728 * always prepend the value to the front of the container.
729 */
730#if __cplusplus201402L < 201103L
731 front_insert_iterator&
732 operator=(typename _Container::const_reference __value)
733 {
734 container->push_front(__value);
735 return *this;
736 }
737#else
738 _GLIBCXX20_CONSTEXPR
739 front_insert_iterator&
740 operator=(const typename _Container::value_type& __value)
741 {
742 container->push_front(__value);
743 return *this;
744 }
745
746 _GLIBCXX20_CONSTEXPR
747 front_insert_iterator&
748 operator=(typename _Container::value_type&& __value)
749 {
750 container->push_front(std::move(__value));
751 return *this;
752 }
753#endif
754
755 /// Simply returns *this.
756 _GLIBCXX20_CONSTEXPR
757 front_insert_iterator&
758 operator*()
759 { return *this; }
760
761 /// Simply returns *this. (This %iterator does not @a move.)
762 _GLIBCXX20_CONSTEXPR
763 front_insert_iterator&
764 operator++()
765 { return *this; }
766
767 /// Simply returns *this. (This %iterator does not @a move.)
768 _GLIBCXX20_CONSTEXPR
769 front_insert_iterator
770 operator++(int)
771 { return *this; }
772 };
773
774 /**
775 * @param __x A container of arbitrary type.
776 * @return An instance of front_insert_iterator working on @p x.
777 *
778 * This wrapper function helps in creating front_insert_iterator instances.
779 * Typing the name of the %iterator requires knowing the precise full
780 * type of the container, which can be tedious and impedes generic
781 * programming. Using this function lets you take advantage of automatic
782 * template parameter deduction, making the compiler match the correct
783 * types for you.
784 */
785 template<typename _Container>
786 _GLIBCXX20_CONSTEXPR
787 inline front_insert_iterator<_Container>
788 front_inserter(_Container& __x)
789 { return front_insert_iterator<_Container>(__x); }
790
791 /**
792 * @brief Turns assignment into insertion.
793 *
794 * These are output iterators, constructed from a container-of-T.
795 * Assigning a T to the iterator inserts it in the container at the
796 * %iterator's position, rather than overwriting the value at that
797 * position.
798 *
799 * (Sequences will actually insert a @e copy of the value before the
800 * %iterator's position.)
801 *
802 * Tip: Using the inserter function to create these iterators can
803 * save typing.
804 */
805 template<typename _Container>
806 class insert_iterator
807 : public iterator<output_iterator_tag, void, void, void, void>
808 {
809#if __cplusplus201402L > 201703L && defined __cpp_lib_concepts
810 using _Iter = std::__detail::__range_iter_t<_Container>;
811
812 protected:
813 _Container* container = nullptr;
814 _Iter iter = _Iter();
815#else
816 typedef typename _Container::iterator _Iter;
817
818 protected:
819 _Container* container;
820 _Iter iter;
821#endif
822
823 public:
824 /// A nested typedef for the type of whatever container you used.
825 typedef _Container container_type;
826
827#if __cplusplus201402L > 201703L && defined __cpp_lib_concepts
828 using difference_type = ptrdiff_t;
829
830 insert_iterator() = default;
831#endif
832
833 /**
834 * The only way to create this %iterator is with a container and an
835 * initial position (a normal %iterator into the container).
836 */
837 _GLIBCXX20_CONSTEXPR
838 insert_iterator(_Container& __x, _Iter __i)
839 : container(std::__addressof(__x)), iter(__i) {}
840
841 /**
842 * @param __value An instance of whatever type
843 * container_type::const_reference is; presumably a
844 * reference-to-const T for container<T>.
845 * @return This %iterator, for chained operations.
846 *
847 * This kind of %iterator maintains its own position in the
848 * container. Assigning a value to the %iterator will insert the
849 * value into the container at the place before the %iterator.
850 *
851 * The position is maintained such that subsequent assignments will
852 * insert values immediately after one another. For example,
853 * @code
854 * // vector v contains A and Z
855 *
856 * insert_iterator i (v, ++v.begin());
857 * i = 1;
858 * i = 2;
859 * i = 3;
860 *
861 * // vector v contains A, 1, 2, 3, and Z
862 * @endcode
863 */
864#if __cplusplus201402L < 201103L
865 insert_iterator&
866 operator=(typename _Container::const_reference __value)
867 {
868 iter = container->insert(iter, __value);
869 ++iter;
870 return *this;
871 }
872#else
873 _GLIBCXX20_CONSTEXPR
874 insert_iterator&
875 operator=(const typename _Container::value_type& __value)
876 {
877 iter = container->insert(iter, __value);
878 ++iter;
879 return *this;
880 }
881
882 _GLIBCXX20_CONSTEXPR
883 insert_iterator&
884 operator=(typename _Container::value_type&& __value)
885 {
886 iter = container->insert(iter, std::move(__value));
887 ++iter;
888 return *this;
889 }
890#endif
891
892 /// Simply returns *this.
893 _GLIBCXX20_CONSTEXPR
894 insert_iterator&
895 operator*()
896 { return *this; }
897
898 /// Simply returns *this. (This %iterator does not @a move.)
899 _GLIBCXX20_CONSTEXPR
900 insert_iterator&
901 operator++()
902 { return *this; }
903
904 /// Simply returns *this. (This %iterator does not @a move.)
905 _GLIBCXX20_CONSTEXPR
906 insert_iterator&
907 operator++(int)
908 { return *this; }
909 };
910
911 /**
912 * @param __x A container of arbitrary type.
913 * @param __i An iterator into the container.
914 * @return An instance of insert_iterator working on @p __x.
915 *
916 * This wrapper function helps in creating insert_iterator instances.
917 * Typing the name of the %iterator requires knowing the precise full
918 * type of the container, which can be tedious and impedes generic
919 * programming. Using this function lets you take advantage of automatic
920 * template parameter deduction, making the compiler match the correct
921 * types for you.
922 */
923#if __cplusplus201402L > 201703L && defined __cpp_lib_concepts
924 template<typename _Container>
925 constexpr insert_iterator<_Container>
926 inserter(_Container& __x, std::__detail::__range_iter_t<_Container> __i)
927 { return insert_iterator<_Container>(__x, __i); }
928#else
929 template<typename _Container, typename _Iterator>
930 inline insert_iterator<_Container>
931 inserter(_Container& __x, _Iterator __i)
932 {
933 return insert_iterator<_Container>(__x,
934 typename _Container::iterator(__i));
935 }
936#endif
937
938 // @} group iterators
939
940_GLIBCXX_END_NAMESPACE_VERSION
941} // namespace
942
943namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)__attribute__ ((__visibility__ ("default")))
944{
945_GLIBCXX_BEGIN_NAMESPACE_VERSION
946
947 // This iterator adapter is @a normal in the sense that it does not
948 // change the semantics of any of the operators of its iterator
949 // parameter. Its primary purpose is to convert an iterator that is
950 // not a class, e.g. a pointer, into an iterator that is a class.
951 // The _Container parameter exists solely so that different containers
952 // using this template can instantiate different types, even if the
953 // _Iterator parameter is the same.
954 template<typename _Iterator, typename _Container>
955 class __normal_iterator
956 {
957 protected:
958 _Iterator _M_current;
959
960 typedef std::iterator_traits<_Iterator> __traits_type;
961
962 public:
963 typedef _Iterator iterator_type;
964 typedef typename __traits_type::iterator_category iterator_category;
965 typedef typename __traits_type::value_type value_type;
966 typedef typename __traits_type::difference_type difference_type;
967 typedef typename __traits_type::reference reference;
968 typedef typename __traits_type::pointer pointer;
969
970#if __cplusplus201402L > 201703L && __cpp_lib_concepts
971 using iterator_concept = std::__detail::__iter_concept<_Iterator>;
972#endif
973
974 _GLIBCXX_CONSTEXPRconstexpr __normal_iterator() _GLIBCXX_NOEXCEPTnoexcept
975 : _M_current(_Iterator()) { }
976
977 explicit _GLIBCXX20_CONSTEXPR
978 __normal_iterator(const _Iterator& __i) _GLIBCXX_NOEXCEPTnoexcept
979 : _M_current(__i) { }
980
981 // Allow iterator to const_iterator conversion
982 template<typename _Iter>
983 _GLIBCXX20_CONSTEXPR
984 __normal_iterator(const __normal_iterator<_Iter,
985 typename __enable_if<
986 (std::__are_same<_Iter, typename _Container::pointer>::__value),
987 _Container>::__type>& __i) _GLIBCXX_NOEXCEPTnoexcept
988 : _M_current(__i.base()) { }
989
990 // Forward iterator requirements
991 _GLIBCXX20_CONSTEXPR
992 reference
993 operator*() const _GLIBCXX_NOEXCEPTnoexcept
994 { return *_M_current; }
995
996 _GLIBCXX20_CONSTEXPR
997 pointer
998 operator->() const _GLIBCXX_NOEXCEPTnoexcept
999 { return _M_current; }
1000
1001 _GLIBCXX20_CONSTEXPR
1002 __normal_iterator&
1003 operator++() _GLIBCXX_NOEXCEPTnoexcept
1004 {
1005 ++_M_current;
1006 return *this;
1007 }
1008
1009 _GLIBCXX20_CONSTEXPR
1010 __normal_iterator
1011 operator++(int) _GLIBCXX_NOEXCEPTnoexcept
1012 { return __normal_iterator(_M_current++); }
1013
1014 // Bidirectional iterator requirements
1015 _GLIBCXX20_CONSTEXPR
1016 __normal_iterator&
1017 operator--() _GLIBCXX_NOEXCEPTnoexcept
1018 {
1019 --_M_current;
1020 return *this;
1021 }
1022
1023 _GLIBCXX20_CONSTEXPR
1024 __normal_iterator
1025 operator--(int) _GLIBCXX_NOEXCEPTnoexcept
1026 { return __normal_iterator(_M_current--); }
1027
1028 // Random access iterator requirements
1029 _GLIBCXX20_CONSTEXPR
1030 reference
1031 operator[](difference_type __n) const _GLIBCXX_NOEXCEPTnoexcept
1032 { return _M_current[__n]; }
1033
1034 _GLIBCXX20_CONSTEXPR
1035 __normal_iterator&
1036 operator+=(difference_type __n) _GLIBCXX_NOEXCEPTnoexcept
1037 { _M_current += __n; return *this; }
1038
1039 _GLIBCXX20_CONSTEXPR
1040 __normal_iterator
1041 operator+(difference_type __n) const _GLIBCXX_NOEXCEPTnoexcept
1042 { return __normal_iterator(_M_current + __n); }
1043
1044 _GLIBCXX20_CONSTEXPR
1045 __normal_iterator&
1046 operator-=(difference_type __n) _GLIBCXX_NOEXCEPTnoexcept
1047 { _M_current -= __n; return *this; }
1048
1049 _GLIBCXX20_CONSTEXPR
1050 __normal_iterator
1051 operator-(difference_type __n) const _GLIBCXX_NOEXCEPTnoexcept
1052 { return __normal_iterator(_M_current - __n); }
1053
1054 _GLIBCXX20_CONSTEXPR
1055 const _Iterator&
1056 base() const _GLIBCXX_NOEXCEPTnoexcept
1057 { return _M_current; }
1058 };
1059
1060 // Note: In what follows, the left- and right-hand-side iterators are
1061 // allowed to vary in types (conceptually in cv-qualification) so that
1062 // comparison between cv-qualified and non-cv-qualified iterators be
1063 // valid. However, the greedy and unfriendly operators in std::rel_ops
1064 // will make overload resolution ambiguous (when in scope) if we don't
1065 // provide overloads whose operands are of the same type. Can someone
1066 // remind me what generic programming is about? -- Gaby
1067
1068#if __cpp_lib_three_way_comparison
1069 template<typename _IteratorL, typename _IteratorR, typename _Container>
1070 requires requires (_IteratorL __lhs, _IteratorR __rhs)
1071 { { __lhs == __rhs } -> std::convertible_to<bool>; }
1072 constexpr bool
1073 operator==(const __normal_iterator<_IteratorL, _Container>& __lhs,
1074 const __normal_iterator<_IteratorR, _Container>& __rhs)
1075 noexcept(noexcept(__lhs.base() == __rhs.base()))
1076 { return __lhs.base() == __rhs.base(); }
1077
1078 template<typename _IteratorL, typename _IteratorR, typename _Container>
1079 constexpr std::__detail::__synth3way_t<_IteratorR, _IteratorL>
1080 operator<=>(const __normal_iterator<_IteratorL, _Container>& __lhs,
1081 const __normal_iterator<_IteratorR, _Container>& __rhs)
1082 noexcept(noexcept(std::__detail::__synth3way(__lhs.base(), __rhs.base())))
1083 { return std::__detail::__synth3way(__lhs.base(), __rhs.base()); }
1084#else
1085 // Forward iterator requirements
1086 template<typename _IteratorL, typename _IteratorR, typename _Container>
1087 _GLIBCXX20_CONSTEXPR
1088 inline bool
1089 operator==(const __normal_iterator<_IteratorL, _Container>& __lhs,
1090 const __normal_iterator<_IteratorR, _Container>& __rhs)
1091 _GLIBCXX_NOEXCEPTnoexcept
1092 { return __lhs.base() == __rhs.base(); }
1093
1094 template<typename _Iterator, typename _Container>
1095 _GLIBCXX20_CONSTEXPR
1096 inline bool
1097 operator==(const __normal_iterator<_Iterator, _Container>& __lhs,
1098 const __normal_iterator<_Iterator, _Container>& __rhs)
1099 _GLIBCXX_NOEXCEPTnoexcept
1100 { return __lhs.base() == __rhs.base(); }
1101
1102 template<typename _IteratorL, typename _IteratorR, typename _Container>
1103 _GLIBCXX20_CONSTEXPR
1104 inline bool
1105 operator!=(const __normal_iterator<_IteratorL, _Container>& __lhs,
1106 const __normal_iterator<_IteratorR, _Container>& __rhs)
1107 _GLIBCXX_NOEXCEPTnoexcept
1108 { return __lhs.base() != __rhs.base(); }
1109
1110 template<typename _Iterator, typename _Container>
1111 _GLIBCXX20_CONSTEXPR
1112 inline bool
1113 operator!=(const __normal_iterator<_Iterator, _Container>& __lhs,
1114 const __normal_iterator<_Iterator, _Container>& __rhs)
1115 _GLIBCXX_NOEXCEPTnoexcept
1116 { return __lhs.base() != __rhs.base(); }
1117
1118 // Random access iterator requirements
1119 template<typename _IteratorL, typename _IteratorR, typename _Container>
1120 inline bool
1121 operator<(const __normal_iterator<_IteratorL, _Container>& __lhs,
1122 const __normal_iterator<_IteratorR, _Container>& __rhs)
1123 _GLIBCXX_NOEXCEPTnoexcept
1124 { return __lhs.base() < __rhs.base(); }
1125
1126 template<typename _Iterator, typename _Container>
1127 _GLIBCXX20_CONSTEXPR
1128 inline bool
1129 operator<(const __normal_iterator<_Iterator, _Container>& __lhs,
1130 const __normal_iterator<_Iterator, _Container>& __rhs)
1131 _GLIBCXX_NOEXCEPTnoexcept
1132 { return __lhs.base() < __rhs.base(); }
1133
1134 template<typename _IteratorL, typename _IteratorR, typename _Container>
1135 inline bool
1136 operator>(const __normal_iterator<_IteratorL, _Container>& __lhs,
1137 const __normal_iterator<_IteratorR, _Container>& __rhs)
1138 _GLIBCXX_NOEXCEPTnoexcept
1139 { return __lhs.base() > __rhs.base(); }
1140
1141 template<typename _Iterator, typename _Container>
1142 _GLIBCXX20_CONSTEXPR
1143 inline bool
1144 operator>(const __normal_iterator<_Iterator, _Container>& __lhs,
1145 const __normal_iterator<_Iterator, _Container>& __rhs)
1146 _GLIBCXX_NOEXCEPTnoexcept
1147 { return __lhs.base() > __rhs.base(); }
1148
1149 template<typename _IteratorL, typename _IteratorR, typename _Container>
1150 inline bool
1151 operator<=(const __normal_iterator<_IteratorL, _Container>& __lhs,
1152 const __normal_iterator<_IteratorR, _Container>& __rhs)
1153 _GLIBCXX_NOEXCEPTnoexcept
1154 { return __lhs.base() <= __rhs.base(); }
1155
1156 template<typename _Iterator, typename _Container>
1157 _GLIBCXX20_CONSTEXPR
1158 inline bool
1159 operator<=(const __normal_iterator<_Iterator, _Container>& __lhs,
1160 const __normal_iterator<_Iterator, _Container>& __rhs)
1161 _GLIBCXX_NOEXCEPTnoexcept
1162 { return __lhs.base() <= __rhs.base(); }
1163
1164 template<typename _IteratorL, typename _IteratorR, typename _Container>
1165 inline bool
1166 operator>=(const __normal_iterator<_IteratorL, _Container>& __lhs,
1167 const __normal_iterator<_IteratorR, _Container>& __rhs)
1168 _GLIBCXX_NOEXCEPTnoexcept
1169 { return __lhs.base() >= __rhs.base(); }
1170
1171 template<typename _Iterator, typename _Container>
1172 _GLIBCXX20_CONSTEXPR
1173 inline bool
1174 operator>=(const __normal_iterator<_Iterator, _Container>& __lhs,
1175 const __normal_iterator<_Iterator, _Container>& __rhs)
1176 _GLIBCXX_NOEXCEPTnoexcept
1177 { return __lhs.base() >= __rhs.base(); }
1178#endif // three-way comparison
1179
1180 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1181 // According to the resolution of DR179 not only the various comparison
1182 // operators but also operator- must accept mixed iterator/const_iterator
1183 // parameters.
1184 template<typename _IteratorL, typename _IteratorR, typename _Container>
1185#if __cplusplus201402L >= 201103L
1186 // DR 685.
1187 _GLIBCXX20_CONSTEXPR
1188 inline auto
1189 operator-(const __normal_iterator<_IteratorL, _Container>& __lhs,
1190 const __normal_iterator<_IteratorR, _Container>& __rhs) noexcept
1191 -> decltype(__lhs.base() - __rhs.base())
1192#else
1193 inline typename __normal_iterator<_IteratorL, _Container>::difference_type
1194 operator-(const __normal_iterator<_IteratorL, _Container>& __lhs,
1195 const __normal_iterator<_IteratorR, _Container>& __rhs)
1196#endif
1197 { return __lhs.base() - __rhs.base(); }
1198
1199 template<typename _Iterator, typename _Container>
1200 _GLIBCXX20_CONSTEXPR
1201 inline typename __normal_iterator<_Iterator, _Container>::difference_type
1202 operator-(const __normal_iterator<_Iterator, _Container>& __lhs,
1203 const __normal_iterator<_Iterator, _Container>& __rhs)
1204 _GLIBCXX_NOEXCEPTnoexcept
1205 { return __lhs.base() - __rhs.base(); }
1206
1207 template<typename _Iterator, typename _Container>
1208 _GLIBCXX20_CONSTEXPR
1209 inline __normal_iterator<_Iterator, _Container>
1210 operator+(typename __normal_iterator<_Iterator, _Container>::difference_type
1211 __n, const __normal_iterator<_Iterator, _Container>& __i)
1212 _GLIBCXX_NOEXCEPTnoexcept
1213 { return __normal_iterator<_Iterator, _Container>(__i.base() + __n); }
1214
1215_GLIBCXX_END_NAMESPACE_VERSION
1216} // namespace
1217
1218namespace std _GLIBCXX_VISIBILITY(default)__attribute__ ((__visibility__ ("default")))
1219{
1220_GLIBCXX_BEGIN_NAMESPACE_VERSION
1221
1222 template<typename _Iterator, typename _Container>
1223 _GLIBCXX20_CONSTEXPR
1224 _Iterator
1225 __niter_base(__gnu_cxx::__normal_iterator<_Iterator, _Container> __it)
1226 _GLIBCXX_NOEXCEPT_IF(std::is_nothrow_copy_constructible<_Iterator>::value)noexcept(std::is_nothrow_copy_constructible<_Iterator>::
value)
1227 { return __it.base(); }
1228
1229#if __cplusplus201402L >= 201103L
1230 /**
1231 * @addtogroup iterators
1232 * @{
1233 */
1234
1235#if __cplusplus201402L > 201703L && __cpp_lib_concepts
1236 template<semiregular _Sent>
1237 class move_sentinel
1238 {
1239 public:
1240 constexpr
1241 move_sentinel()
1242 noexcept(is_nothrow_default_constructible_v<_Sent>)
1243 : _M_last() { }
1244
1245 constexpr explicit
1246 move_sentinel(_Sent __s)
1247 noexcept(is_nothrow_move_constructible_v<_Sent>)
1248 : _M_last(std::move(__s)) { }
1249
1250 template<typename _S2> requires convertible_to<const _S2&, _Sent>
1251 constexpr
1252 move_sentinel(const move_sentinel<_S2>& __s)
1253 noexcept(is_nothrow_constructible_v<_Sent, const _S2&>)
1254 : _M_last(__s.base())
1255 { }
1256
1257 template<typename _S2> requires assignable_from<_Sent&, const _S2&>
1258 constexpr move_sentinel&
1259 operator=(const move_sentinel<_S2>& __s)
1260 noexcept(is_nothrow_assignable_v<_Sent, const _S2&>)
1261 {
1262 _M_last = __s.base();
1263 return *this;
1264 }
1265
1266 constexpr _Sent
1267 base() const
1268 noexcept(is_nothrow_copy_constructible_v<_Sent>)
1269 { return _M_last; }
1270
1271 private:
1272 _Sent _M_last;
1273 };
1274#endif // C++20
1275
1276 // 24.4.3 Move iterators
1277 /**
1278 * Class template move_iterator is an iterator adapter with the same
1279 * behavior as the underlying iterator except that its dereference
1280 * operator implicitly converts the value returned by the underlying
1281 * iterator's dereference operator to an rvalue reference. Some
1282 * generic algorithms can be called with move iterators to replace
1283 * copying with moving.
1284 */
1285 template<typename _Iterator>
1286 class move_iterator
1287 {
1288 _Iterator _M_current;
1289
1290 using __traits_type = iterator_traits<_Iterator>;
1291#if __cplusplus201402L > 201703L && __cpp_lib_concepts
1292 using __base_cat = typename __traits_type::iterator_category;
1293#else
1294 using __base_ref = typename __traits_type::reference;
1295#endif
1296
1297 public:
1298 using iterator_type = _Iterator;
1299
1300#if __cplusplus201402L > 201703L && __cpp_lib_concepts
1301 using iterator_concept = input_iterator_tag;
1302 using iterator_category
1303 = __detail::__clamp_iter_cat<__base_cat, random_access_iterator_tag>;
1304 using value_type = iter_value_t<_Iterator>;
1305 using difference_type = iter_difference_t<_Iterator>;
1306 using pointer = _Iterator;
1307 using reference = iter_rvalue_reference_t<_Iterator>;
1308#else
1309 typedef typename __traits_type::iterator_category iterator_category;
1310 typedef typename __traits_type::value_type value_type;
1311 typedef typename __traits_type::difference_type difference_type;
1312 // NB: DR 680.
1313 typedef _Iterator pointer;
1314 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1315 // 2106. move_iterator wrapping iterators returning prvalues
1316 typedef typename conditional<is_reference<__base_ref>::value,
1317 typename remove_reference<__base_ref>::type&&,
1318 __base_ref>::type reference;
1319#endif
1320
1321 _GLIBCXX17_CONSTEXPR
1322 move_iterator()
1323 : _M_current() { }
1324
1325 explicit _GLIBCXX17_CONSTEXPR
1326 move_iterator(iterator_type __i)
1327 : _M_current(std::move(__i)) { }
1328
1329 template<typename _Iter>
1330 _GLIBCXX17_CONSTEXPR
1331 move_iterator(const move_iterator<_Iter>& __i)
1332 : _M_current(__i.base()) { }
1333
1334#if __cplusplus201402L <= 201703L
1335 _GLIBCXX17_CONSTEXPR iterator_type
1336 base() const
1337 { return _M_current; }
1338#else
1339 constexpr iterator_type
1340 base() const &
1341#if __cpp_lib_concepts
1342 requires copy_constructible<iterator_type>
1343#endif
1344 { return _M_current; }
1345
1346 constexpr iterator_type
1347 base() &&
1348 { return std::move(_M_current); }
1349#endif
1350
1351 _GLIBCXX17_CONSTEXPR reference
1352 operator*() const
1353#if __cplusplus201402L > 201703L && __cpp_lib_concepts
1354 { return ranges::iter_move(_M_current); }
1355#else
1356 { return static_cast<reference>(*_M_current); }
1357#endif
1358
1359 _GLIBCXX17_CONSTEXPR pointer
1360 operator->() const
1361 { return _M_current; }
1362
1363 _GLIBCXX17_CONSTEXPR move_iterator&
1364 operator++()
1365 {
1366 ++_M_current;
1367 return *this;
1368 }
1369
1370 _GLIBCXX17_CONSTEXPR move_iterator
1371 operator++(int)
1372 {
1373 move_iterator __tmp = *this;
1374 ++_M_current;
1375 return __tmp;
1376 }
1377
1378#if __cpp_lib_concepts
1379 constexpr void
1380 operator++(int) requires (!forward_iterator<_Iterator>)
1381 { ++_M_current; }
1382#endif
1383
1384 _GLIBCXX17_CONSTEXPR move_iterator&
1385 operator--()
1386 {
1387 --_M_current;
1388 return *this;
1389 }
1390
1391 _GLIBCXX17_CONSTEXPR move_iterator
1392 operator--(int)
1393 {
1394 move_iterator __tmp = *this;
1395 --_M_current;
1396 return __tmp;
1397 }
1398
1399 _GLIBCXX17_CONSTEXPR move_iterator
1400 operator+(difference_type __n) const
1401 { return move_iterator(_M_current + __n); }
1402
1403 _GLIBCXX17_CONSTEXPR move_iterator&
1404 operator+=(difference_type __n)
1405 {
1406 _M_current += __n;
1407 return *this;
1408 }
1409
1410 _GLIBCXX17_CONSTEXPR move_iterator
1411 operator-(difference_type __n) const
1412 { return move_iterator(_M_current - __n); }
1413
1414 _GLIBCXX17_CONSTEXPR move_iterator&
1415 operator-=(difference_type __n)
1416 {
1417 _M_current -= __n;
1418 return *this;
1419 }
1420
1421 _GLIBCXX17_CONSTEXPR reference
1422 operator[](difference_type __n) const
1423#if __cplusplus201402L > 201703L && __cpp_lib_concepts
1424 { return ranges::iter_move(_M_current + __n); }
1425#else
1426 { return std::move(_M_current[__n]); }
1427#endif
1428
1429#if __cplusplus201402L > 201703L && __cpp_lib_concepts
1430 template<sentinel_for<_Iterator> _Sent>
1431 friend constexpr bool
1432 operator==(const move_iterator& __x, const move_sentinel<_Sent>& __y)
1433 { return __x.base() == __y.base(); }
1434
1435 template<sized_sentinel_for<_Iterator> _Sent>
1436 friend constexpr iter_difference_t<_Iterator>
1437 operator-(const move_sentinel<_Sent>& __x, const move_iterator& __y)
1438 { return __x.base() - __y.base(); }
1439
1440 template<sized_sentinel_for<_Iterator> _Sent>
1441 friend constexpr iter_difference_t<_Iterator>
1442 operator-(const move_iterator& __x, const move_sentinel<_Sent>& __y)
1443 { return __x.base() - __y.base(); }
1444
1445 friend constexpr iter_rvalue_reference_t<_Iterator>
1446 iter_move(const move_iterator& __i)
1447 noexcept(noexcept(ranges::iter_move(__i._M_current)))
1448 { return ranges::iter_move(__i._M_current); }
1449
1450 template<indirectly_swappable<_Iterator> _Iter2>
1451 friend constexpr void
1452 iter_swap(const move_iterator& __x, const move_iterator<_Iter2>& __y)
1453 noexcept(noexcept(ranges::iter_swap(__x._M_current, __y._M_current)))
1454 { return ranges::iter_swap(__x._M_current, __y._M_current); }
1455#endif // C++20
1456 };
1457
1458 template<typename _IteratorL, typename _IteratorR>
1459 inline _GLIBCXX17_CONSTEXPR bool
1460 operator==(const move_iterator<_IteratorL>& __x,
1461 const move_iterator<_IteratorR>& __y)
1462#if __cplusplus201402L > 201703L && __cpp_lib_concepts
1463 requires requires { { __x.base() == __y.base() } -> convertible_to<bool>; }
1464#endif
1465 { return __x.base() == __y.base(); }
1466
1467#if __cpp_lib_three_way_comparison
1468 template<typename _IteratorL,
1469 three_way_comparable_with<_IteratorL> _IteratorR>
1470 constexpr compare_three_way_result_t<_IteratorL, _IteratorR>
1471 operator<=>(const move_iterator<_IteratorL>& __x,
1472 const move_iterator<_IteratorR>& __y)
1473 { return __x.base() <=> __y.base(); }
1474#else
1475 template<typename _IteratorL, typename _IteratorR>
1476 inline _GLIBCXX17_CONSTEXPR bool
1477 operator!=(const move_iterator<_IteratorL>& __x,
1478 const move_iterator<_IteratorR>& __y)
1479 { return !(__x == __y); }
1480#endif
1481
1482 template<typename _IteratorL, typename _IteratorR>
1483 inline _GLIBCXX17_CONSTEXPR bool
1484 operator<(const move_iterator<_IteratorL>& __x,
1485 const move_iterator<_IteratorR>& __y)
1486#if __cplusplus201402L > 201703L && __cpp_lib_concepts
1487 requires requires { { __x.base() < __y.base() } -> convertible_to<bool>; }
1488#endif
1489 { return __x.base() < __y.base(); }
1490
1491 template<typename _IteratorL, typename _IteratorR>
1492 inline _GLIBCXX17_CONSTEXPR bool
1493 operator<=(const move_iterator<_IteratorL>& __x,
1494 const move_iterator<_IteratorR>& __y)
1495#if __cplusplus201402L > 201703L && __cpp_lib_concepts
1496 requires requires { { __y.base() < __x.base() } -> convertible_to<bool>; }
1497#endif
1498 { return !(__y < __x); }
1499
1500 template<typename _IteratorL, typename _IteratorR>
1501 inline _GLIBCXX17_CONSTEXPR bool
1502 operator>(const move_iterator<_IteratorL>& __x,
1503 const move_iterator<_IteratorR>& __y)
1504#if __cplusplus201402L > 201703L && __cpp_lib_concepts
1505 requires requires { { __y.base() < __x.base() } -> convertible_to<bool>; }
1506#endif
1507 { return __y < __x; }
1508
1509 template<typename _IteratorL, typename _IteratorR>
1510 inline _GLIBCXX17_CONSTEXPR bool
1511 operator>=(const move_iterator<_IteratorL>& __x,
1512 const move_iterator<_IteratorR>& __y)
1513#if __cplusplus201402L > 201703L && __cpp_lib_concepts
1514 requires requires { { __x.base() < __y.base() } -> convertible_to<bool>; }
1515#endif
1516 { return !(__x < __y); }
1517
1518#if ! (__cplusplus201402L > 201703L && __cpp_lib_concepts)
1519 // Note: See __normal_iterator operators note from Gaby to understand
1520 // why we have these extra overloads for some move_iterator operators.
1521
1522 // These extra overloads are not needed in C++20, because the ones above
1523 // are constrained with a requires-clause and so overload resolution will
1524 // prefer them to greedy unconstrained function templates.
1525
1526 template<typename _Iterator>
1527 inline _GLIBCXX17_CONSTEXPR bool
1528 operator==(const move_iterator<_Iterator>& __x,
1529 const move_iterator<_Iterator>& __y)
1530 { return __x.base() == __y.base(); }
1531
1532 template<typename _Iterator>
1533 inline _GLIBCXX17_CONSTEXPR bool
1534 operator!=(const move_iterator<_Iterator>& __x,
1535 const move_iterator<_Iterator>& __y)
1536 { return !(__x == __y); }
1537
1538 template<typename _Iterator>
1539 inline _GLIBCXX17_CONSTEXPR bool
1540 operator<(const move_iterator<_Iterator>& __x,
1541 const move_iterator<_Iterator>& __y)
1542 { return __x.base() < __y.base(); }
1543
1544 template<typename _Iterator>
1545 inline _GLIBCXX17_CONSTEXPR bool
1546 operator<=(const move_iterator<_Iterator>& __x,
1547 const move_iterator<_Iterator>& __y)
1548 { return !(__y < __x); }
1549
1550 template<typename _Iterator>
1551 inline _GLIBCXX17_CONSTEXPR bool
1552 operator>(const move_iterator<_Iterator>& __x,
1553 const move_iterator<_Iterator>& __y)
1554 { return __y < __x; }
1555
1556 template<typename _Iterator>
1557 inline _GLIBCXX17_CONSTEXPR bool
1558 operator>=(const move_iterator<_Iterator>& __x,
1559 const move_iterator<_Iterator>& __y)
1560 { return !(__x < __y); }
1561#endif // ! C++20
1562
1563 // DR 685.
1564 template<typename _IteratorL, typename _IteratorR>
1565 inline _GLIBCXX17_CONSTEXPR auto
1566 operator-(const move_iterator<_IteratorL>& __x,
1567 const move_iterator<_IteratorR>& __y)
1568 -> decltype(__x.base() - __y.base())
1569 { return __x.base() - __y.base(); }
1570
1571 template<typename _Iterator>
1572 inline _GLIBCXX17_CONSTEXPR move_iterator<_Iterator>
1573 operator+(typename move_iterator<_Iterator>::difference_type __n,
1574 const move_iterator<_Iterator>& __x)
1575 { return __x + __n; }
1576
1577 template<typename _Iterator>
1578 inline _GLIBCXX17_CONSTEXPR move_iterator<_Iterator>
1579 make_move_iterator(_Iterator __i)
1580 { return move_iterator<_Iterator>(std::move(__i)); }
1581
1582 template<typename _Iterator, typename _ReturnType
1583 = typename conditional<__move_if_noexcept_cond
1584 <typename iterator_traits<_Iterator>::value_type>::value,
1585 _Iterator, move_iterator<_Iterator>>::type>
1586 inline _GLIBCXX17_CONSTEXPR _ReturnType
1587 __make_move_if_noexcept_iterator(_Iterator __i)
1588 { return _ReturnType(__i); }
1589
1590 // Overload for pointers that matches std::move_if_noexcept more closely,
1591 // returning a constant iterator when we don't want to move.
1592 template<typename _Tp, typename _ReturnType
1593 = typename conditional<__move_if_noexcept_cond<_Tp>::value,
1594 const _Tp*, move_iterator<_Tp*>>::type>
1595 inline _GLIBCXX17_CONSTEXPR _ReturnType
1596 __make_move_if_noexcept_iterator(_Tp* __i)
1597 { return _ReturnType(__i); }
1598
1599#if __cplusplus201402L > 201703L && __cpp_lib_concepts
1600 // [iterators.common] Common iterators
1601
1602 namespace __detail
1603 {
1604 template<typename _It>
1605 concept __common_iter_has_arrow = indirectly_readable<const _It>
1606 && (requires(const _It& __it) { __it.operator->(); }
1607 || is_reference_v<iter_reference_t<_It>>
1608 || constructible_from<iter_value_t<_It>, iter_reference_t<_It>>);
1609
1610 } // namespace __detail
1611
1612 /// An iterator/sentinel adaptor for representing a non-common range.
1613 template<input_or_output_iterator _It, sentinel_for<_It> _Sent>
1614 requires (!same_as<_It, _Sent>) && copyable<_It>
1615 class common_iterator
1616 {
1617 template<typename _Tp, typename _Up>
1618 static constexpr bool
1619 _S_noexcept1()
1620 {
1621 if constexpr (is_trivially_default_constructible_v<_Tp>)
1622 return is_nothrow_assignable_v<_Tp, _Up>;
1623 else
1624 return is_nothrow_constructible_v<_Tp, _Up>;
1625 }
1626
1627 template<typename _It2, typename _Sent2>
1628 static constexpr bool
1629 _S_noexcept()
1630 { return _S_noexcept1<_It, _It2>() && _S_noexcept1<_Sent, _Sent2>(); }
1631
1632 class _Proxy
1633 {
1634 iter_value_t<_It> _M_keep;
1635
1636 _Proxy(iter_reference_t<_It>&& __x)
1637 : _M_keep(std::move(__x)) { }
1638
1639 friend class common_iterator;
1640
1641 public:
1642 const iter_value_t<_It>*
1643 operator->() const
1644 { return std::__addressof(_M_keep); }
1645 };
1646
1647 public:
1648 constexpr
1649 common_iterator()
1650 noexcept(is_nothrow_default_constructible_v<_It>)
1651 : _M_it(), _M_index(0)
1652 { }
1653
1654 constexpr
1655 common_iterator(_It __i)
1656 noexcept(is_nothrow_move_constructible_v<_It>)
1657 : _M_it(std::move(__i)), _M_index(0)
1658 { }
1659
1660 constexpr
1661 common_iterator(_Sent __s)
1662 noexcept(is_nothrow_move_constructible_v<_Sent>)
1663 : _M_sent(std::move(__s)), _M_index(1)
1664 { }
1665
1666 template<typename _It2, typename _Sent2>
1667 requires convertible_to<const _It2&, _It>
1668 && convertible_to<const _Sent2&, _Sent>
1669 constexpr
1670 common_iterator(const common_iterator<_It2, _Sent2>& __x)
1671 noexcept(_S_noexcept<const _It2&, const _Sent2&>())
1672 : _M_valueless(), _M_index(__x._M_index)
1673 {
1674 if (_M_index == 0)
1675 {
1676 if constexpr (is_trivially_default_constructible_v<_It>)
1677 _M_it = std::move(__x._M_it);
1678 else
1679 ::new((void*)std::__addressof(_M_it)) _It(__x._M_it);
1680 }
1681 else if (_M_index == 1)
1682 {
1683 if constexpr (is_trivially_default_constructible_v<_Sent>)
1684 _M_sent = std::move(__x._M_sent);
1685 else
1686 ::new((void*)std::__addressof(_M_sent)) _Sent(__x._M_sent);
1687 }
1688 }
1689
1690 constexpr
1691 common_iterator(const common_iterator& __x)
1692 noexcept(_S_noexcept<const _It&, const _Sent&>())
1693 : _M_valueless(), _M_index(__x._M_index)
1694 {
1695 if (_M_index == 0)
1696 {
1697 if constexpr (is_trivially_default_constructible_v<_It>)
1698 _M_it = std::move(__x._M_it);
1699 else
1700 ::new((void*)std::__addressof(_M_it)) _It(__x._M_it);
1701 }
1702 else if (_M_index == 1)
1703 {
1704 if constexpr (is_trivially_default_constructible_v<_Sent>)
1705 _M_sent = std::move(__x._M_sent);
1706 else
1707 ::new((void*)std::__addressof(_M_sent)) _Sent(__x._M_sent);
1708 }
1709 }
1710
1711 common_iterator&
1712 operator=(const common_iterator& __x)
1713 noexcept(is_nothrow_copy_assignable_v<_It>
1714 && is_nothrow_copy_assignable_v<_Sent>
1715 && is_nothrow_copy_constructible_v<_It>
1716 && is_nothrow_copy_constructible_v<_Sent>)
1717 {
1718 return this->operator=<_It, _Sent>(__x);
1719 }
1720
1721 template<typename _It2, typename _Sent2>
1722 requires convertible_to<const _It2&, _It>
1723 && convertible_to<const _Sent2&, _Sent>
1724 && assignable_from<_It&, const _It2&>
1725 && assignable_from<_Sent&, const _Sent2&>
1726 common_iterator&
1727 operator=(const common_iterator<_It2, _Sent2>& __x)
1728 noexcept(is_nothrow_constructible_v<_It, const _It2&>
1729 && is_nothrow_constructible_v<_Sent, const _Sent2&>
1730 && is_nothrow_assignable_v<_It, const _It2&>
1731 && is_nothrow_assignable_v<_Sent, const _Sent2&>)
1732 {
1733 switch(_M_index << 2 | __x._M_index)
1734 {
1735 case 0b0000:
1736 _M_it = __x._M_it;
1737 break;
1738 case 0b0101:
1739 _M_sent = __x._M_sent;
1740 break;
1741 case 0b0001:
1742 _M_it.~_It();
1743 _M_index = -1;
1744 [[fallthrough]];
1745 case 0b1001:
1746 ::new((void*)std::__addressof(_M_sent)) _Sent(__x._M_sent);
1747 _M_index = 1;
1748 break;
1749 case 0b0100:
1750 _M_sent.~_Sent();
1751 _M_index = -1;
1752 [[fallthrough]];
1753 case 0b1000:
1754 ::new((void*)std::__addressof(_M_it)) _It(__x._M_it);
1755 _M_index = 0;
1756 break;
1757 default:
1758 __glibcxx_assert(__x._M_has_value());
1759 __builtin_unreachable();
1760 }
1761 return *this;
1762 }
1763
1764 ~common_iterator()
1765 {
1766 switch (_M_index)
1767 {
1768 case 0:
1769 _M_it.~_It();
1770 break;
1771 case 1:
1772 _M_sent.~_Sent();
1773 break;
1774 }
1775 }
1776
1777 decltype(auto)
1778 operator*()
1779 {
1780 __glibcxx_assert(_M_index == 0);
1781 return *_M_it;
1782 }
1783
1784 decltype(auto)
1785 operator*() const requires __detail::__dereferenceable<const _It>
1786 {
1787 __glibcxx_assert(_M_index == 0);
1788 return *_M_it;
1789 }
1790
1791 decltype(auto)
1792 operator->() const requires __detail::__common_iter_has_arrow<_It>
1793 {
1794 __glibcxx_assert(_M_index == 0);
1795 if constexpr (is_pointer_v<_It> || requires { _M_it.operator->(); })
1796 return _M_it;
1797 else if constexpr (is_reference_v<iter_reference_t<_It>>)
1798 {
1799 auto&& __tmp = *_M_it;
1800 return std::__addressof(__tmp);
1801 }
1802 else
1803 return _Proxy{*_M_it};
1804 }
1805
1806 common_iterator&
1807 operator++()
1808 {
1809 __glibcxx_assert(_M_index == 0);
1810 ++_M_it;
1811 return *this;
1812 }
1813
1814 decltype(auto)
1815 operator++(int)
1816 {
1817 __glibcxx_assert(_M_index == 0);
1818 if constexpr (forward_iterator<_It>)
1819 {
1820 common_iterator __tmp = *this;
1821 ++*this;
1822 return __tmp;
1823 }
1824 else
1825 return _M_it++;
1826 }
1827
1828 template<typename _It2, sentinel_for<_It> _Sent2>
1829 requires sentinel_for<_Sent, _It2>
1830 friend bool
1831 operator==(const common_iterator& __x,
1832 const common_iterator<_It2, _Sent2>& __y)
1833 {
1834 switch(__x._M_index << 2 | __y._M_index)
1835 {
1836 case 0b0000:
1837 case 0b0101:
1838 return true;
1839 case 0b0001:
1840 return __x._M_it == __y._M_sent;
1841 case 0b0100:
1842 return __x._M_sent == __y._M_it;
1843 default:
1844 __glibcxx_assert(__x._M_has_value());
1845 __glibcxx_assert(__y._M_has_value());
1846 __builtin_unreachable();
1847 }
1848 }
1849
1850 template<typename _It2, sentinel_for<_It> _Sent2>
1851 requires sentinel_for<_Sent, _It2> && equality_comparable_with<_It, _It2>
1852 friend bool
1853 operator==(const common_iterator& __x,
1854 const common_iterator<_It2, _Sent2>& __y)
1855 {
1856 switch(__x._M_index << 2 | __y._M_index)
1857 {
1858 case 0b0101:
1859 return true;
1860 case 0b0000:
1861 return __x._M_it == __y._M_it;
1862 case 0b0001:
1863 return __x._M_it == __y._M_sent;
1864 case 0b0100:
1865 return __x._M_sent == __y._M_it;
1866 default:
1867 __glibcxx_assert(__x._M_has_value());
1868 __glibcxx_assert(__y._M_has_value());
1869 __builtin_unreachable();
1870 }
1871 }
1872
1873 template<sized_sentinel_for<_It> _It2, sized_sentinel_for<_It> _Sent2>
1874 requires sized_sentinel_for<_Sent, _It2>
1875 friend iter_difference_t<_It2>
1876 operator-(const common_iterator& __x,
1877 const common_iterator<_It2, _Sent2>& __y)
1878 {
1879 switch(__x._M_index << 2 | __y._M_index)
1880 {
1881 case 0b0101:
1882 return 0;
1883 case 0b0000:
1884 return __x._M_it - __y._M_it;
1885 case 0b0001:
1886 return __x._M_it - __y._M_sent;
1887 case 0b0100:
1888 return __x._M_sent - __y._M_it;
1889 default:
1890 __glibcxx_assert(__x._M_has_value());
1891 __glibcxx_assert(__y._M_has_value());
1892 __builtin_unreachable();
1893 }
1894 }
1895
1896 friend iter_rvalue_reference_t<_It>
1897 iter_move(const common_iterator& __i)
1898 noexcept(noexcept(ranges::iter_move(std::declval<const _It&>())))
1899 requires input_iterator<_It>
1900 {
1901 __glibcxx_assert(__i._M_index == 0);
1902 return ranges::iter_move(__i._M_it);
1903 }
1904
1905 template<indirectly_swappable<_It> _It2, typename _Sent2>
1906 friend void
1907 iter_swap(const common_iterator& __x,
1908 const common_iterator<_It2, _Sent2>& __y)
1909 noexcept(noexcept(ranges::iter_swap(std::declval<const _It&>(),
1910 std::declval<const _It2&>())))
1911 {
1912 __glibcxx_assert(__x._M_index == 0);
1913 __glibcxx_assert(__y._M_index == 0);
1914 return ranges::iter_swap(__x._M_it, __y._M_it);
1915 }
1916
1917 private:
1918 template<input_or_output_iterator _It2, sentinel_for<_It2> _Sent2>
1919 friend class common_iterator;
1920
1921 bool _M_has_value() const noexcept { return _M_index < 2; }
1922
1923 union
1924 {
1925 _It _M_it;
1926 _Sent _M_sent;
1927 unsigned char _M_valueless;
1928 };
1929 unsigned char _M_index; // 0==_M_it, 1==_M_sent, 2==valueless
1930 };
1931
1932 template<typename _It, typename _Sent>
1933 struct incrementable_traits<common_iterator<_It, _Sent>>
1934 {
1935 using difference_type = iter_difference_t<_It>;
1936 };
1937
1938 template<input_iterator _It, typename _Sent>
1939 struct iterator_traits<common_iterator<_It, _Sent>>
1940 {
1941 private:
1942 template<typename _Iter>
1943 struct __ptr
1944 {
1945 using type = void;
1946 };
1947
1948 template<typename _Iter>
1949 requires __detail::__common_iter_has_arrow<_Iter>
1950 struct __ptr<_Iter>
1951 {
1952 using _CIter = common_iterator<_Iter, _Sent>;
1953 using type = decltype(std::declval<const _CIter&>().operator->());
1954 };
1955
1956 public:
1957 using iterator_concept = conditional_t<forward_iterator<_It>,
1958 forward_iterator_tag, input_iterator_tag>;
1959 using iterator_category = __detail::__clamp_iter_cat<
1960 typename iterator_traits<_It>::iterator_category,
1961 forward_iterator_tag, input_iterator_tag>;
1962 using value_type = iter_value_t<_It>;
1963 using difference_type = iter_difference_t<_It>;
1964 using pointer = typename __ptr<_It>::type;
1965 using reference = iter_reference_t<_It>;
1966 };
1967
1968 // [iterators.counted] Counted iterators
1969
1970 /// An iterator adaptor that keeps track of the distance to the end.
1971 template<input_or_output_iterator _It>
1972 class counted_iterator
1973 {
1974 public:
1975 using iterator_type = _It;
1976
1977 constexpr counted_iterator() = default;
1978
1979 constexpr
1980 counted_iterator(_It __i, iter_difference_t<_It> __n)
1981 : _M_current(std::move(__i)), _M_length(__n)
1982 { __glibcxx_assert(__n >= 0); }
1983
1984 template<typename _It2>
1985 requires convertible_to<const _It2&, _It>
1986 constexpr
1987 counted_iterator(const counted_iterator<_It2>& __x)
1988 : _M_current(__x._M_current), _M_length(__x._M_length)
1989 { }
1990
1991 template<typename _It2>
1992 requires assignable_from<_It&, const _It2&>
1993 constexpr counted_iterator&
1994 operator=(const counted_iterator<_It2>& __x)
1995 {
1996 _M_current = __x._M_current;
1997 _M_length = __x._M_length;
1998 return *this;
1999 }
2000
2001 constexpr _It
2002 base() const &
2003 noexcept(is_nothrow_copy_constructible_v<_It>)
2004 requires copy_constructible<_It>
2005 { return _M_current; }
2006
2007 constexpr _It
2008 base() &&
2009 noexcept(is_nothrow_move_constructible_v<_It>)
2010 { return std::move(_M_current); }
2011
2012 constexpr iter_difference_t<_It>
2013 count() const noexcept { return _M_length; }
2014
2015 constexpr decltype(auto)
2016 operator*()
2017 noexcept(noexcept(*_M_current))
2018 { return *_M_current; }
2019
2020 constexpr decltype(auto)
2021 operator*() const
2022 noexcept(noexcept(*_M_current))
2023 requires __detail::__dereferenceable<const _It>
2024 { return *_M_current; }
2025
2026 constexpr counted_iterator&
2027 operator++()
2028 {
2029 __glibcxx_assert(_M_length > 0);
2030 ++_M_current;
2031 --_M_length;
2032 return *this;
2033 }
2034
2035 decltype(auto)
2036 operator++(int)
2037 {
2038 __glibcxx_assert(_M_length > 0);
2039 --_M_length;
2040 __tryif (true)
2041 {
2042 return _M_current++;
2043 } __catch(...)if (false) {
2044 ++_M_length;
2045 __throw_exception_again;
2046 }
2047
2048 }
2049
2050 constexpr counted_iterator
2051 operator++(int) requires forward_iterator<_It>
2052 {
2053 auto __tmp = *this;
2054 ++*this;
2055 return __tmp;
2056 }
2057
2058 constexpr counted_iterator&
2059 operator--() requires bidirectional_iterator<_It>
2060 {
2061 --_M_current;
2062 ++_M_length;
2063 return *this;
2064 }
2065
2066 constexpr counted_iterator
2067 operator--(int) requires bidirectional_iterator<_It>
2068 {
2069 auto __tmp = *this;
2070 --*this;
2071 return __tmp;
2072 }
2073
2074 constexpr counted_iterator
2075 operator+(iter_difference_t<_It> __n) const
2076 requires random_access_iterator<_It>
2077 { return counted_iterator(_M_current + __n, _M_length - __n); }
2078
2079 friend constexpr counted_iterator
2080 operator+(iter_difference_t<_It> __n, const counted_iterator& __x)
2081 requires random_access_iterator<_It>
2082 { return __x + __n; }
2083
2084 constexpr counted_iterator&
2085 operator+=(iter_difference_t<_It> __n)
2086 requires random_access_iterator<_It>
2087 {
2088 __glibcxx_assert(__n <= _M_length);
2089 _M_current += __n;
2090 _M_length -= __n;
2091 return *this;
2092 }
2093
2094 constexpr counted_iterator
2095 operator-(iter_difference_t<_It> __n) const
2096 requires random_access_iterator<_It>
2097 { return counted_iterator(_M_current - __n, _M_length + __n); }
2098
2099 template<common_with<_It> _It2>
2100 friend constexpr iter_difference_t<_It2>
2101 operator-(const counted_iterator& __x,
2102 const counted_iterator<_It2>& __y)
2103 { return __y._M_length - __x._M_length; }
2104
2105 friend constexpr iter_difference_t<_It>
2106 operator-(const counted_iterator& __x, default_sentinel_t)
2107 { return -__x._M_length; }
2108
2109 friend constexpr iter_difference_t<_It>
2110 operator-(default_sentinel_t, const counted_iterator& __y)
2111 { return __y._M_length; }
2112
2113 constexpr counted_iterator&
2114 operator-=(iter_difference_t<_It> __n)
2115 requires random_access_iterator<_It>
2116 {
2117 __glibcxx_assert(-__n <= _M_length);
2118 _M_current -= __n;
2119 _M_length += __n;
2120 return *this;
2121 }
2122
2123 constexpr decltype(auto)
2124 operator[](iter_difference_t<_It> __n) const
2125 noexcept(noexcept(_M_current[__n]))
2126 requires random_access_iterator<_It>
2127 {
2128 __glibcxx_assert(__n < _M_length);
2129 return _M_current[__n];
2130 }
2131
2132 template<common_with<_It> _It2>
2133 friend constexpr bool
2134 operator==(const counted_iterator& __x,
2135 const counted_iterator<_It2>& __y)
2136 { return __x._M_length == __y._M_length; }
2137
2138 friend constexpr bool
2139 operator==(const counted_iterator& __x, default_sentinel_t)
2140 { return __x._M_length == 0; }
2141
2142 template<common_with<_It> _It2>
2143 friend constexpr strong_ordering
2144 operator<=>(const counted_iterator& __x,
2145 const counted_iterator<_It2>& __y)
2146 { return __y._M_length <=> __x._M_length; }
2147
2148 friend constexpr iter_rvalue_reference_t<_It>
2149 iter_move(const counted_iterator& __i)
2150 noexcept(noexcept(ranges::iter_move(__i._M_current)))
2151 requires input_iterator<_It>
2152 { return ranges::iter_move(__i._M_current); }
2153
2154 template<indirectly_swappable<_It> _It2>
2155 friend constexpr void
2156 iter_swap(const counted_iterator& __x,
2157 const counted_iterator<_It2>& __y)
2158 noexcept(noexcept(ranges::iter_swap(__x._M_current, __y._M_current)))
2159 { ranges::iter_swap(__x._M_current, __y._M_current); }
2160
2161 private:
2162 template<input_or_output_iterator _It2> friend class counted_iterator;
2163
2164 _It _M_current = _It();
2165 iter_difference_t<_It> _M_length = 0;
2166 };
2167
2168 template<typename _It>
2169 struct incrementable_traits<counted_iterator<_It>>
2170 {
2171 using difference_type = iter_difference_t<_It>;
2172 };
2173
2174 template<input_iterator _It>
2175 struct iterator_traits<counted_iterator<_It>> : iterator_traits<_It>
2176 {
2177 using pointer = void;
2178 };
2179#endif // C++20
2180
2181 // @} group iterators
2182
2183 template<typename _Iterator>
2184 auto
2185 __niter_base(move_iterator<_Iterator> __it)
2186 -> decltype(make_move_iterator(__niter_base(__it.base())))
2187 { return make_move_iterator(__niter_base(__it.base())); }
2188
2189 template<typename _Iterator>
2190 struct __is_move_iterator<move_iterator<_Iterator> >
2191 {
2192 enum { __value = 1 };
2193 typedef __true_type __type;
2194 };
2195
2196 template<typename _Iterator>
2197 auto
2198 __miter_base(move_iterator<_Iterator> __it)
2199 -> decltype(__miter_base(__it.base()))
2200 { return __miter_base(__it.base()); }
2201
2202#define _GLIBCXX_MAKE_MOVE_ITERATOR(_Iter)std::make_move_iterator(_Iter) std::make_move_iterator(_Iter)
2203#define _GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(_Iter)std::__make_move_if_noexcept_iterator(_Iter) \
2204 std::__make_move_if_noexcept_iterator(_Iter)
2205#else
2206#define _GLIBCXX_MAKE_MOVE_ITERATOR(_Iter)std::make_move_iterator(_Iter) (_Iter)
2207#define _GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(_Iter)std::__make_move_if_noexcept_iterator(_Iter) (_Iter)
2208#endif // C++11
2209
2210#if __cpp_deduction_guides >= 201606
2211 // These helper traits are used for deduction guides
2212 // of associative containers.
2213 template<typename _InputIterator>
2214 using __iter_key_t = remove_const_t<
2215 typename iterator_traits<_InputIterator>::value_type::first_type>;
2216
2217 template<typename _InputIterator>
2218 using __iter_val_t =
2219 typename iterator_traits<_InputIterator>::value_type::second_type;
2220
2221 template<typename _T1, typename _T2>
2222 struct pair;
2223
2224 template<typename _InputIterator>
2225 using __iter_to_alloc_t =
2226 pair<add_const_t<__iter_key_t<_InputIterator>>,
2227 __iter_val_t<_InputIterator>>;
2228#endif // __cpp_deduction_guides
2229
2230_GLIBCXX_END_NAMESPACE_VERSION
2231} // namespace
2232
2233#ifdef _GLIBCXX_DEBUG
2234# include <debug/stl_iterator.h>
2235#endif
2236
2237#endif