35#define _GLIBCXX_SPAN 1
38#pragma GCC system_header
41#define __glibcxx_want_span
42#define __glibcxx_want_span_initializer_list
50#ifdef __cpp_lib_span_initializer_list
53namespace std _GLIBCXX_VISIBILITY(default)
55_GLIBCXX_BEGIN_NAMESPACE_VERSION
57 inline constexpr size_t dynamic_extent =
static_cast<size_t>(-1);
59 template<
typename _Type,
size_t _Extent>
64 template<
typename _Tp>
65 inline constexpr bool __is_span =
false;
67 template<
typename _Tp,
size_t _Num>
68 inline constexpr bool __is_span<span<_Tp, _Num>> =
true;
70 template<
typename _Tp>
71 inline constexpr bool __is_std_array =
false;
73 template<
typename _Tp,
size_t _Num>
74 inline constexpr bool __is_std_array<std::array<_Tp, _Num>> =
true;
76 template<
size_t _Extent>
77 class __extent_storage
82 __extent_storage([[maybe_unused]]
size_t __n)
noexcept
83 { __glibcxx_assert(__n == _Extent); }
87 __extent_storage(integral_constant<size_t, _Extent>)
noexcept
92 __extent_storage(integral_constant<size_t, _Gob>) =
delete;
94 [[__gnu__::__always_inline__]]
95 static constexpr size_t
101 class __extent_storage<dynamic_extent>
104 [[__gnu__::__always_inline__]]
106 __extent_storage(
size_t __extent) noexcept
107 : _M_extent_value(__extent)
110 [[__gnu__::__always_inline__]]
112 _M_extent() const noexcept
113 {
return this->_M_extent_value; }
116 size_t _M_extent_value;
119 template<
typename _Type>
struct __span_ptr { _Type*
const _M_ptr; };
123 template<
typename _Type,
size_t _Extent = dynamic_extent>
126 template<
size_t _Offset,
size_t _Count>
127 static constexpr size_t
130 if constexpr (_Count != dynamic_extent)
132 else if constexpr (extent != dynamic_extent)
133 return _Extent - _Offset;
135 return dynamic_extent;
140 template<
typename _Tp,
size_t _ArrayExtent>
141 requires (_Extent == dynamic_extent || _ArrayExtent == _Extent)
142 using __is_compatible_array = __is_array_convertible<_Type, _Tp>;
144 template<
typename _Ref>
145 using __is_compatible_ref
146 = __is_array_convertible<_Type, remove_reference_t<_Ref>>;
152 static inline constexpr integral_constant<size_t, _Nm> __v{};
156 using element_type = _Type;
157 using value_type = remove_cv_t<_Type>;
158 using size_type = size_t;
159 using difference_type = ptrdiff_t;
160 using pointer = _Type*;
161 using const_pointer =
const _Type*;
162 using reference = element_type&;
163 using const_reference =
const element_type&;
164 using iterator = __gnu_cxx::__normal_iterator<pointer, __iter_tag>;
165 using reverse_iterator = std::reverse_iterator<iterator>;
166#if __cplusplus > 202002L
167 using const_iterator = std::const_iterator<iterator>;
168 using const_reverse_iterator = std::const_iterator<reverse_iterator>;
172 static constexpr size_t extent = _Extent;
178 requires (_Extent == dynamic_extent || _Extent == 0)
179 : _M_ptr(
nullptr), _M_extent(__v<0>)
182 template<contiguous_iterator _It>
183 requires __is_compatible_ref<iter_reference_t<_It>>::value
184 constexpr explicit(extent != dynamic_extent)
185 span(_It __first, size_type __count)
188 { __glibcxx_requires_valid_range(__first, __first + __count); }
190 template<contiguous_iterator _It, sized_sentinel_for<_It> _End>
191 requires __is_compatible_ref<iter_reference_t<_It>>::value
192 && (!is_convertible_v<_End, size_type>)
193 constexpr explicit(extent != dynamic_extent)
194 span(_It __first, _End __last)
195 noexcept(
noexcept(__last - __first))
197 _M_extent(static_cast<size_type>(__last - __first))
198 { __glibcxx_requires_valid_range(__first, __last); }
200 template<
size_t _ArrayExtent>
201 requires (_Extent == dynamic_extent || _ArrayExtent == _Extent)
203 span(type_identity_t<element_type> (&__arr)[_ArrayExtent]) noexcept
204 : _M_ptr(__arr), _M_extent(__v<_ArrayExtent>)
207 template<
typename _Tp,
size_t _ArrayExtent>
208 requires __is_compatible_array<_Tp, _ArrayExtent>::value
210 span(array<_Tp, _ArrayExtent>& __arr) noexcept
211 : _M_ptr(__arr.data()), _M_extent(__v<_ArrayExtent>)
214 template<
typename _Tp,
size_t _ArrayExtent>
215 requires __is_compatible_array<const _Tp, _ArrayExtent>::value
217 span(
const array<_Tp, _ArrayExtent>& __arr) noexcept
218 : _M_ptr(__arr.data()), _M_extent(__v<_ArrayExtent>)
221 template<
typename _Range>
222 requires (!__detail::__is_span<remove_cvref_t<_Range>>)
223 && (!__detail::__is_std_array<remove_cvref_t<_Range>>)
224 && (!is_array_v<remove_cvref_t<_Range>>)
225 && ranges::contiguous_range<_Range> && ranges::sized_range<_Range>
226 && (ranges::borrowed_range<_Range> || is_const_v<element_type>)
227 && __is_compatible_ref<ranges::range_reference_t<_Range>>::value
228 constexpr explicit(extent != dynamic_extent)
229 span(_Range&& __range)
230 noexcept(
noexcept(ranges::data(__range))
231 &&
noexcept(ranges::size(__range)))
232 : _M_ptr(ranges::
data(__range)), _M_extent(ranges::
size(__range))
235#if __cpp_lib_span_initializer_list >= 202311L
236#pragma GCC diagnostic push
237#pragma GCC diagnostic ignored "-Winit-list-lifetime"
239 explicit(extent != dynamic_extent)
240 span(initializer_list<value_type> __il)
241 requires (is_const_v<_Type>)
242 : _M_ptr(__il.
begin()), _M_extent(__il.
size())
244#pragma GCC diagnostic pop
248 span(
const span&)
noexcept =
default;
250 template<
typename _OType,
size_t _OExtent>
251 requires (_Extent == dynamic_extent || _OExtent == dynamic_extent
252 || _Extent == _OExtent)
253 && (__is_array_convertible<_Type, _OType>::value)
255 explicit(extent != dynamic_extent && _OExtent == dynamic_extent)
256 span(
const span<_OType, _OExtent>& __s) noexcept
257 : _M_ptr(__s.data()), _M_extent(__s.size())
261 operator=(
const span&)
noexcept =
default;
267 size() const noexcept
268 {
return this->_M_extent._M_extent(); }
272 size_bytes() const noexcept
273 {
return this->_M_extent._M_extent() *
sizeof(element_type); }
277 empty() const noexcept
278 {
return size() == 0; }
284 front() const noexcept
286 __glibcxx_assert(!
empty());
287 return *this->_M_ptr;
292 back() const noexcept
294 __glibcxx_assert(!
empty());
295 return *(this->_M_ptr + (
size() - 1));
300 operator[](size_type __idx)
const noexcept
302 __glibcxx_assert(__idx <
size());
303 return *(this->_M_ptr + __idx);
306#if __cpp_lib_span >= 202311L
309 at(size_type __idx)
const
312 __throw_out_of_range_fmt(__N(
"span::at(%zu) out-of-range for span "
313 "of size %zu"), __idx, this->
size());
314 return *(this->_M_ptr + __idx);
320 data() const noexcept
321 {
return this->_M_ptr; }
327 begin() const noexcept
328 {
return iterator(this->_M_ptr); }
333 {
return iterator(this->_M_ptr + this->
size()); }
336 constexpr reverse_iterator
338 {
return reverse_iterator(this->
end()); }
341 constexpr reverse_iterator
342 rend() const noexcept
343 {
return reverse_iterator(this->
begin()); }
345#if __cplusplus > 202002L
347 constexpr const_iterator
352 constexpr const_iterator
353 cend() const noexcept
357 constexpr const_reverse_iterator
362 constexpr const_reverse_iterator
363 crend() const noexcept
369 template<
size_t _Count>
371 constexpr span<element_type, _Count>
372 first() const noexcept
374 if constexpr (_Extent == dynamic_extent)
375 __glibcxx_assert(_Count <=
size());
377 static_assert(_Count <= extent);
378 using _Sp = span<element_type, _Count>;
379 return _Sp{ _SizedPtr{this->
data()} };
383 constexpr span<element_type, dynamic_extent>
384 first(size_type __count)
const noexcept
386 __glibcxx_assert(__count <=
size());
387 return { this->
data(), __count };
390 template<
size_t _Count>
392 constexpr span<element_type, _Count>
393 last() const noexcept
395 if constexpr (_Extent == dynamic_extent)
396 __glibcxx_assert(_Count <=
size());
398 static_assert(_Count <= extent);
399 using _Sp = span<element_type, _Count>;
400 return _Sp{ _SizedPtr{this->
data() + (this->
size() - _Count)} };
404 constexpr span<element_type, dynamic_extent>
405 last(size_type __count)
const noexcept
407 __glibcxx_assert(__count <=
size());
408 return { this->
data() + (this->
size() - __count), __count };
411 template<
size_t _Offset,
size_t _Count = dynamic_extent>
414 subspan() const noexcept
415 -> span<element_type, _S_subspan_extent<_Offset, _Count>()>
417 if constexpr (_Extent == dynamic_extent)
419 __glibcxx_assert(_Offset <=
size());
422 static_assert(_Offset <= extent);
424 using _Sp = span<element_type, _S_subspan_extent<_Offset, _Count>()>;
426 if constexpr (_Count == dynamic_extent)
427 return _Sp{ this->
data() + _Offset, this->
size() - _Offset };
430 if constexpr (_Extent == dynamic_extent)
432 __glibcxx_assert(_Count <=
size());
433 __glibcxx_assert(_Count <= (
size() - _Offset));
437 static_assert(_Count <= extent);
438 static_assert(_Count <= (extent - _Offset));
440 return _Sp{ _SizedPtr{this->
data() + _Offset} };
445 constexpr span<element_type, dynamic_extent>
446 subspan(size_type __offset, size_type __count = dynamic_extent)
const
449 __glibcxx_assert(__offset <=
size());
450 if (__count == dynamic_extent)
451 __count = this->
size() - __offset;
454 __glibcxx_assert(__count <=
size());
455 __glibcxx_assert(__offset + __count <=
size());
457 return {this->
data() + __offset, __count};
461 template<
typename,
size_t>
friend class span;
464 using _SizedPtr = __detail::__span_ptr<_Type>;
467 [[__gnu__::__always_inline__]]
469 span(_SizedPtr __ptr)
noexcept
470 requires (extent != dynamic_extent)
471 : _M_ptr(__ptr._M_ptr), _M_extent(__v<extent>)
475 [[no_unique_address]] __detail::__extent_storage<extent> _M_extent;
480 template<
typename _Type,
size_t _ArrayExtent>
481 span(_Type(&)[_ArrayExtent]) -> span<_Type, _ArrayExtent>;
483 template<
typename _Type,
size_t _ArrayExtent>
486 template<
typename _Type,
size_t _ArrayExtent>
488 -> span<const _Type, _ArrayExtent>;
490 template<contiguous_iterator _Iter,
typename _End>
492 -> span<remove_reference_t<iter_reference_t<_Iter>>>;
494 template<ranges::contiguous_range _Range>
496 -> span<remove_reference_t<ranges::range_reference_t<_Range&>>>;
498 template<
typename _Type,
size_t _Extent>
501 span<
const byte, _Extent == dynamic_extent
502 ? dynamic_extent : _Extent *
sizeof(_Type)>
503 as_bytes(span<_Type, _Extent> __sp)
noexcept
505 auto data =
reinterpret_cast<const byte*
>(__sp.data());
506 auto size = __sp.size_bytes();
507 constexpr auto extent = _Extent == dynamic_extent
508 ? dynamic_extent : _Extent *
sizeof(_Type);
509 return span<const byte, extent>{
data,
size};
512 template<
typename _Type,
size_t _Extent>
513 requires (!is_const_v<_Type>)
515 span<
byte, _Extent == dynamic_extent
516 ? dynamic_extent : _Extent * sizeof(_Type)>
517 as_writable_bytes [[nodiscard]] (span<_Type, _Extent> __sp) noexcept
519 auto data =
reinterpret_cast<byte*
>(__sp.data());
520 auto size = __sp.size_bytes();
521 constexpr auto extent = _Extent == dynamic_extent
522 ? dynamic_extent : _Extent *
sizeof(_Type);
523 return span<byte, extent>{
data,
size};
529 template<
typename _ElementType,
size_t _Extent>
530 inline constexpr bool
531 enable_borrowed_range<span<_ElementType, _Extent>> =
true;
534 template<
typename _ElementType,
size_t _Extent>
535 inline constexpr bool
536 enable_view<span<_ElementType, _Extent>> =
true;
538_GLIBCXX_END_NAMESPACE_VERSION
constexpr _Tp * to_address(_Tp *__ptr) noexcept
Obtain address referenced by a pointer to an object.
_Tp * end(valarray< _Tp > &__va) noexcept
Return an iterator pointing to one past the last element of the valarray.
_Tp * begin(valarray< _Tp > &__va) noexcept
Return an iterator pointing to the first element of the valarray.
ISO C++ entities toplevel namespace is std.
constexpr auto rbegin(_Container &__cont) noexcept(noexcept(__cont.rbegin())) -> decltype(__cont.rbegin())
Return a reverse iterator pointing to the last element of the container.
constexpr auto cend(const _Container &__cont) noexcept(noexcept(std::end(__cont))) -> decltype(std::end(__cont))
Return an iterator pointing to one past the last element of the const container.
constexpr auto empty(const _Container &__cont) noexcept(noexcept(__cont.empty())) -> decltype(__cont.empty())
Return whether a container is empty.
constexpr auto crbegin(const _Container &__cont) noexcept(noexcept(std::rbegin(__cont))) -> decltype(std::rbegin(__cont))
Return a reverse iterator pointing to the last element of the const container.
constexpr auto size(const _Container &__cont) noexcept(noexcept(__cont.size())) -> decltype(__cont.size())
Return the size of a container.
constexpr auto data(_Container &__cont) noexcept(noexcept(__cont.data())) -> decltype(__cont.data())
Return the data pointer of a container.
constexpr auto cbegin(const _Container &__cont) noexcept(noexcept(std::begin(__cont))) -> decltype(std::begin(__cont))
Return an iterator pointing to the first element of the const container.
constexpr auto rend(_Container &__cont) noexcept(noexcept(__cont.rend())) -> decltype(__cont.rend())
Return a reverse iterator pointing one past the first element of the container.
constexpr auto crend(const _Container &__cont) noexcept(noexcept(std::rend(__cont))) -> decltype(std::rend(__cont))
Return a reverse iterator pointing one past the first element of the const container.
Implementation details not part of the namespace std interface.
A standard container for storing a fixed size sequence of elements.