1 // Components for manipulating non-owning sequences of characters -*- C++ -*-
3 // Copyright (C) 2013-2016 Free Software Foundation, Inc.
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)
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.
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.
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/>.
26 * This is a Standard C++ Library header.
30 // N3762 basic_string_view library
33 #ifndef _GLIBCXX_STRING_VIEW
34 #define _GLIBCXX_STRING_VIEW 1
36 #pragma GCC system_header
38 #if __cplusplus <= 201402L
39 # include <bits/c++17_warning.h>
44 #include <bits/char_traits.h>
45 #include <bits/functional_hash.h>
46 #include <bits/range_access.h>
48 namespace std _GLIBCXX_VISIBILITY(default)
50 _GLIBCXX_BEGIN_NAMESPACE_VERSION
53 * @class basic_string_view <string_view>
54 * @brief A non-owning reference to a string.
59 * @tparam _CharT Type of character
60 * @tparam _Traits Traits for character type, defaults to
61 * char_traits<_CharT>.
63 * A basic_string_view looks like this:
70 template<typename _CharT, typename _Traits = std::char_traits<_CharT>>
71 class basic_string_view
76 using traits_type = _Traits;
77 using value_type = _CharT;
78 using pointer = const _CharT*;
79 using const_pointer = const _CharT*;
80 using reference = const _CharT&;
81 using const_reference = const _CharT&;
82 using const_iterator = const _CharT*;
83 using iterator = const_iterator;
84 using const_reverse_iterator = std::reverse_iterator<const_iterator>;
85 using reverse_iterator = const_reverse_iterator;
86 using size_type = size_t;
87 using difference_type = ptrdiff_t;
88 static constexpr size_type npos = size_type(-1);
90 // [string.view.cons], construct/copy
93 basic_string_view() noexcept
94 : _M_len{0}, _M_str{nullptr}
97 constexpr basic_string_view(const basic_string_view&) noexcept = default;
99 constexpr basic_string_view(const _CharT* __str)
100 : _M_len{__str == nullptr ? 0 : traits_type::length(__str)},
104 constexpr basic_string_view(const _CharT* __str, size_type __len)
110 operator=(const basic_string_view&) noexcept = default;
112 // [string.view.iterators], iterators
114 constexpr const_iterator
115 begin() const noexcept
116 { return this->_M_str; }
118 constexpr const_iterator
120 { return this->_M_str + this->_M_len; }
122 constexpr const_iterator
123 cbegin() const noexcept
124 { return this->_M_str; }
126 constexpr const_iterator
127 cend() const noexcept
128 { return this->_M_str + this->_M_len; }
130 const_reverse_iterator
131 rbegin() const noexcept
132 { return const_reverse_iterator(this->end()); }
134 const_reverse_iterator
135 rend() const noexcept
136 { return const_reverse_iterator(this->begin()); }
138 const_reverse_iterator
139 crbegin() const noexcept
140 { return const_reverse_iterator(this->end()); }
142 const_reverse_iterator
143 crend() const noexcept
144 { return const_reverse_iterator(this->begin()); }
146 // [string.view.capacity], capacity
149 size() const noexcept
150 { return this->_M_len; }
153 length() const noexcept
157 max_size() const noexcept
159 return (npos - sizeof(size_type) - sizeof(void*))
160 / sizeof(value_type) / 4;
164 empty() const noexcept
165 { return this->_M_len == 0; }
167 // [string.view.access], element access
169 constexpr const _CharT&
170 operator[](size_type __pos) const noexcept
172 // TODO: Assert to restore in a way compatible with the constexpr.
173 // __glibcxx_assert(__pos < this->_M_len);
174 return *(this->_M_str + __pos);
177 constexpr const _CharT&
178 at(size_type __pos) const
180 return __pos < this->_M_len
181 ? *(this->_M_str + __pos)
182 : (__throw_out_of_range_fmt(__N("basic_string_view::at: __pos "
183 "(which is %zu) >= this->size() "
185 __pos, this->size()),
189 constexpr const _CharT&
192 // TODO: Assert to restore in a way compatible with the constexpr.
193 // __glibcxx_assert(this->_M_len > 0);
194 return *this->_M_str;
197 constexpr const _CharT&
200 // TODO: Assert to restore in a way compatible with the constexpr.
201 // __glibcxx_assert(this->_M_len > 0);
202 return *(this->_M_str + this->_M_len - 1);
205 constexpr const _CharT*
206 data() const noexcept
207 { return this->_M_str; }
209 // [string.view.modifiers], modifiers:
212 remove_prefix(size_type __n)
214 __glibcxx_assert(this->_M_len >= __n);
220 remove_suffix(size_type __n)
221 { this->_M_len -= __n; }
224 swap(basic_string_view& __sv) noexcept
226 std::swap(this->_M_len, __sv._M_len);
227 std::swap(this->_M_str, __sv._M_str);
231 // [string.view.ops], string operations:
234 copy(_CharT* __str, size_type __n, size_type __pos = 0) const
236 __glibcxx_requires_string_len(__str, __n);
237 if (__pos > this->_M_len)
238 __throw_out_of_range_fmt(__N("basic_string_view::copy: __pos "
239 "(which is %zu) > this->size() "
241 __pos, this->size());
242 size_type __rlen{std::min(__n, size_type{this->_M_len - __pos})};
243 for (auto __begin = this->_M_str + __pos,
244 __end = __begin + __rlen; __begin != __end;)
245 *__str++ = *__begin++;
250 // [string.view.ops], string operations:
252 constexpr basic_string_view
253 substr(size_type __pos, size_type __n=npos) const
255 return __pos <= this->_M_len
256 ? basic_string_view{this->_M_str + __pos,
257 std::min(__n, size_type{this->_M_len - __pos})}
258 : (__throw_out_of_range_fmt(__N("basic_string_view::substr: __pos "
259 "(which is %zu) > this->size() "
261 __pos, this->size()), basic_string_view{});
265 compare(basic_string_view __str) const noexcept
267 int __ret = traits_type::compare(this->_M_str, __str._M_str,
268 std::min(this->_M_len, __str._M_len));
270 __ret = _S_compare(this->_M_len, __str._M_len);
275 compare(size_type __pos1, size_type __n1, basic_string_view __str) const
276 { return this->substr(__pos1, __n1).compare(__str); }
279 compare(size_type __pos1, size_type __n1,
280 basic_string_view __str, size_type __pos2, size_type __n2) const
281 { return this->substr(__pos1, __n1).compare(__str.substr(__pos2, __n2)); }
284 compare(const _CharT* __str) const noexcept
285 { return this->compare(basic_string_view{__str}); }
288 compare(size_type __pos1, size_type __n1, const _CharT* __str) const
289 { return this->substr(__pos1, __n1).compare(basic_string_view{__str}); }
292 compare(size_type __pos1, size_type __n1,
293 const _CharT* __str, size_type __n2) const
295 return this->substr(__pos1, __n1)
296 .compare(basic_string_view(__str, __n2));
300 find(basic_string_view __str, size_type __pos = 0) const noexcept
301 { return this->find(__str._M_str, __pos, __str._M_len); }
304 find(_CharT __c, size_type __pos=0) const noexcept;
307 find(const _CharT* __str, size_type __pos, size_type __n) const noexcept;
310 find(const _CharT* __str, size_type __pos=0) const noexcept
311 { return this->find(__str, __pos, traits_type::length(__str)); }
314 rfind(basic_string_view __str, size_type __pos = npos) const noexcept
315 { return this->rfind(__str._M_str, __pos, __str._M_len); }
318 rfind(_CharT __c, size_type __pos = npos) const noexcept;
321 rfind(const _CharT* __str, size_type __pos, size_type __n) const noexcept;
324 rfind(const _CharT* __str, size_type __pos = npos) const noexcept
325 { return this->rfind(__str, __pos, traits_type::length(__str)); }
328 find_first_of(basic_string_view __str, size_type __pos = 0) const noexcept
329 { return this->find_first_of(__str._M_str, __pos, __str._M_len); }
332 find_first_of(_CharT __c, size_type __pos = 0) const noexcept
333 { return this->find(__c, __pos); }
336 find_first_of(const _CharT* __str, size_type __pos, size_type __n) const;
339 find_first_of(const _CharT* __str, size_type __pos = 0) const noexcept
340 { return this->find_first_of(__str, __pos, traits_type::length(__str)); }
343 find_last_of(basic_string_view __str,
344 size_type __pos = npos) const noexcept
345 { return this->find_last_of(__str._M_str, __pos, __str._M_len); }
348 find_last_of(_CharT __c, size_type __pos=npos) const noexcept
349 { return this->rfind(__c, __pos); }
352 find_last_of(const _CharT* __str, size_type __pos, size_type __n) const;
355 find_last_of(const _CharT* __str, size_type __pos = npos) const noexcept
356 { return this->find_last_of(__str, __pos, traits_type::length(__str)); }
359 find_first_not_of(basic_string_view __str,
360 size_type __pos = 0) const noexcept
361 { return this->find_first_not_of(__str._M_str, __pos, __str._M_len); }
364 find_first_not_of(_CharT __c, size_type __pos = 0) const noexcept;
367 find_first_not_of(const _CharT* __str,
368 size_type __pos, size_type __n) const;
371 find_first_not_of(const _CharT* __str, size_type __pos = 0) const noexcept
373 return this->find_first_not_of(__str, __pos,
374 traits_type::length(__str));
378 find_last_not_of(basic_string_view __str,
379 size_type __pos = npos) const noexcept
380 { return this->find_last_not_of(__str._M_str, __pos, __str._M_len); }
383 find_last_not_of(_CharT __c, size_type __pos = npos) const noexcept;
386 find_last_not_of(const _CharT* __str,
387 size_type __pos, size_type __n) const;
390 find_last_not_of(const _CharT* __str,
391 size_type __pos = npos) const noexcept
393 return this->find_last_not_of(__str, __pos,
394 traits_type::length(__str));
398 _M_check(size_type __pos, const char* __s) const
400 if (__pos > this->size())
401 __throw_out_of_range_fmt(__N("%s: __pos (which is %zu) > "
402 "this->size() (which is %zu)"),
403 __s, __pos, this->size());
407 // NB: _M_limit doesn't check for a bad __pos value.
409 _M_limit(size_type __pos, size_type __off) const _GLIBCXX_NOEXCEPT
411 const bool __testoff = __off < this->size() - __pos;
412 return __testoff ? __off : this->size() - __pos;
418 _S_compare(size_type __n1, size_type __n2) noexcept
420 return difference_type{__n1 - __n2} > std::numeric_limits<int>::max()
421 ? std::numeric_limits<int>::max()
422 : difference_type{__n1 - __n2} < std::numeric_limits<int>::min()
423 ? std::numeric_limits<int>::min()
424 : static_cast<int>(difference_type{__n1 - __n2});
428 const _CharT* _M_str;
430 _GLIBCXX_END_NAMESPACE_VERSION
432 // [string.view.comparison], non-member basic_string_view comparison function
435 _GLIBCXX_BEGIN_NAMESPACE_VERSION
436 // Identity transform to make ADL work with just one argument.
438 template<typename _Tp = void>
440 { typedef _Tp type; };
443 struct __identity<void>;
445 template<typename _Tp>
446 using __idt = typename __identity<_Tp>::type;
447 _GLIBCXX_END_NAMESPACE_VERSION
450 _GLIBCXX_BEGIN_NAMESPACE_VERSION
452 template<typename _CharT, typename _Traits>
454 operator==(basic_string_view<_CharT, _Traits> __x,
455 basic_string_view<_CharT, _Traits> __y) noexcept
456 { return __x.compare(__y) == 0; }
458 template<typename _CharT, typename _Traits>
460 operator==(basic_string_view<_CharT, _Traits> __x,
461 __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
462 { return __x.compare(__y) == 0; }
464 template<typename _CharT, typename _Traits>
466 operator==(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
467 basic_string_view<_CharT, _Traits> __y) noexcept
468 { return __x.compare(__y) == 0; }
470 template<typename _CharT, typename _Traits>
472 operator!=(basic_string_view<_CharT, _Traits> __x,
473 basic_string_view<_CharT, _Traits> __y) noexcept
474 { return !(__x == __y); }
476 template<typename _CharT, typename _Traits>
478 operator!=(basic_string_view<_CharT, _Traits> __x,
479 __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
480 { return !(__x == __y); }
482 template<typename _CharT, typename _Traits>
484 operator!=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
485 basic_string_view<_CharT, _Traits> __y) noexcept
486 { return !(__x == __y); }
488 template<typename _CharT, typename _Traits>
490 operator< (basic_string_view<_CharT, _Traits> __x,
491 basic_string_view<_CharT, _Traits> __y) noexcept
492 { return __x.compare(__y) < 0; }
494 template<typename _CharT, typename _Traits>
496 operator< (basic_string_view<_CharT, _Traits> __x,
497 __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
498 { return __x.compare(__y) < 0; }
500 template<typename _CharT, typename _Traits>
502 operator< (__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
503 basic_string_view<_CharT, _Traits> __y) noexcept
504 { return __x.compare(__y) < 0; }
506 template<typename _CharT, typename _Traits>
508 operator> (basic_string_view<_CharT, _Traits> __x,
509 basic_string_view<_CharT, _Traits> __y) noexcept
510 { return __x.compare(__y) > 0; }
512 template<typename _CharT, typename _Traits>
514 operator> (basic_string_view<_CharT, _Traits> __x,
515 __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
516 { return __x.compare(__y) > 0; }
518 template<typename _CharT, typename _Traits>
520 operator> (__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
521 basic_string_view<_CharT, _Traits> __y) noexcept
522 { return __x.compare(__y) > 0; }
524 template<typename _CharT, typename _Traits>
526 operator<=(basic_string_view<_CharT, _Traits> __x,
527 basic_string_view<_CharT, _Traits> __y) noexcept
528 { return __x.compare(__y) <= 0; }
530 template<typename _CharT, typename _Traits>
532 operator<=(basic_string_view<_CharT, _Traits> __x,
533 __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
534 { return __x.compare(__y) <= 0; }
536 template<typename _CharT, typename _Traits>
538 operator<=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
539 basic_string_view<_CharT, _Traits> __y) noexcept
540 { return __x.compare(__y) <= 0; }
542 template<typename _CharT, typename _Traits>
544 operator>=(basic_string_view<_CharT, _Traits> __x,
545 basic_string_view<_CharT, _Traits> __y) noexcept
546 { return __x.compare(__y) >= 0; }
548 template<typename _CharT, typename _Traits>
550 operator>=(basic_string_view<_CharT, _Traits> __x,
551 __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
552 { return __x.compare(__y) >= 0; }
554 template<typename _CharT, typename _Traits>
556 operator>=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
557 basic_string_view<_CharT, _Traits> __y) noexcept
558 { return __x.compare(__y) >= 0; }
560 // [string.view.io], Inserters and extractors
561 template<typename _CharT, typename _Traits>
562 inline basic_ostream<_CharT, _Traits>&
563 operator<<(basic_ostream<_CharT, _Traits>& __os,
564 basic_string_view<_CharT,_Traits> __str)
565 { return __ostream_insert(__os, __str.data(), __str.size()); }
568 // basic_string_view typedef names
570 using string_view = basic_string_view<char>;
571 #ifdef _GLIBCXX_USE_WCHAR_T
572 using wstring_view = basic_string_view<wchar_t>;
574 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
575 using u16string_view = basic_string_view<char16_t>;
576 using u32string_view = basic_string_view<char32_t>;
579 // [string.view.hash], hash support:
581 template<typename _Tp>
585 struct hash<string_view>
586 : public __hash_base<size_t, string_view>
589 operator()(const string_view& __str) const noexcept
590 { return std::_Hash_impl::hash(__str.data(), __str.length()); }
594 struct __is_fast_hash<hash<string_view>> : std::false_type
597 #ifdef _GLIBCXX_USE_WCHAR_T
599 struct hash<wstring_view>
600 : public __hash_base<size_t, wstring>
603 operator()(const wstring_view& __s) const noexcept
604 { return std::_Hash_impl::hash(__s.data(),
605 __s.length() * sizeof(wchar_t)); }
609 struct __is_fast_hash<hash<wstring_view>> : std::false_type
613 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
615 struct hash<u16string_view>
616 : public __hash_base<size_t, u16string_view>
619 operator()(const u16string_view& __s) const noexcept
620 { return std::_Hash_impl::hash(__s.data(),
621 __s.length() * sizeof(char16_t)); }
625 struct __is_fast_hash<hash<u16string_view>> : std::false_type
629 struct hash<u32string_view>
630 : public __hash_base<size_t, u32string_view>
633 operator()(const u32string_view& __s) const noexcept
634 { return std::_Hash_impl::hash(__s.data(),
635 __s.length() * sizeof(char32_t)); }
639 struct __is_fast_hash<hash<u32string_view>> : std::false_type
643 inline namespace literals
645 inline namespace string_view_literals
647 _GLIBCXX_BEGIN_NAMESPACE_VERSION
649 inline constexpr basic_string_view<char>
650 operator""sv(const char* __str, size_t __len)
651 { return basic_string_view<char>{__str, __len}; }
653 #ifdef _GLIBCXX_USE_WCHAR_T
654 inline constexpr basic_string_view<wchar_t>
655 operator""sv(const wchar_t* __str, size_t __len)
656 { return basic_string_view<wchar_t>{__str, __len}; }
659 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
660 inline constexpr basic_string_view<char16_t>
661 operator""sv(const char16_t* __str, size_t __len)
662 { return basic_string_view<char16_t>{__str, __len}; }
664 inline constexpr basic_string_view<char32_t>
665 operator""sv(const char32_t* __str, size_t __len)
666 { return basic_string_view<char32_t>{__str, __len}; }
669 _GLIBCXX_END_NAMESPACE_VERSION
670 } // namespace string_literals
671 } // namespace literals
673 _GLIBCXX_END_NAMESPACE_VERSION
676 #include <bits/string_view.tcc>
678 #endif // __cplusplus <= 201402L
680 #endif // _GLIBCXX_EXPERIMENTAL_STRING_VIEW