#include <bits/stl_iterator.h>
#include <bits/range_access.h>
+#if __cpp_lib_concepts
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
private:
size_t _M_extent_value;
};
-
} // namespace __detail
template<typename _Type, size_t _Extent = dynamic_extent>
return dynamic_extent;
}
- template<typename _Tp>
- using __is_compatible = is_convertible<_Tp(*)[], _Type(*)[]>;
-
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 3255. span's array constructor is too strict
- template<typename _Tp, size_t _ArrayExtent,
- typename = enable_if_t<_Extent == dynamic_extent
- || _ArrayExtent == _Extent>>
- using __is_compatible_array = __is_compatible<_Tp>;
+ template<typename _Tp, size_t _ArrayExtent>
+ using __is_compatible_array = __and_<
+ bool_constant<(_Extent == dynamic_extent || _ArrayExtent == _Extent)>,
+ __is_array_convertible<_Type, _Tp>>;
+
+ template<typename _Iter, typename _Ref = iter_reference_t<_Iter>>
+ using __is_compatible_iterator = __and_<
+ bool_constant<contiguous_iterator<_Iter>>,
+ is_lvalue_reference<iter_reference_t<_Iter>>,
+ is_same<iter_value_t<_Iter>, remove_cvref_t<_Ref>>,
+ __is_array_convertible<_Type, remove_reference_t<_Ref>>>;
+
+ template<typename _Range>
+ using __is_compatible_range
+ = __is_compatible_iterator<ranges::iterator_t<_Range>>;
public:
// member types
using value_type = remove_cv_t<_Type>;
using element_type = _Type;
- using index_type = size_t;
+ using size_type = size_t;
using reference = element_type&;
using const_reference = const element_type&;
using pointer = _Type*;
using reverse_iterator = std::reverse_iterator<iterator>;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
using difference_type = ptrdiff_t;
- // Official wording has no size_type -- why??
- // using size_type = size_t;
// member constants
static inline constexpr size_t extent = _Extent;
// constructors
- template<bool _DefaultConstructible = (_Extent + 1u) <= 1u,
- enable_if_t<_DefaultConstructible>* = nullptr>
- constexpr
- span() noexcept : _M_extent(0), _M_ptr(nullptr)
- { }
+ constexpr
+ span() noexcept
+ requires ((_Extent + 1u) <= 1u)
+ : _M_extent(0), _M_ptr(nullptr)
+ { }
constexpr
span(const span&) noexcept = default;
- template<typename _Tp, size_t _ArrayExtent,
- typename = _Require<__is_compatible_array<_Tp, _ArrayExtent>>>
+ template<typename _Tp, size_t _ArrayExtent>
+ requires (__is_compatible_array<_Tp, _ArrayExtent>::value)
constexpr
span(_Tp (&__arr)[_ArrayExtent]) noexcept
: span(static_cast<pointer>(__arr), _ArrayExtent)
{ }
- template<typename _Tp, size_t _ArrayExtent,
- typename = _Require<__is_compatible_array<_Tp, _ArrayExtent>>>
+ template<typename _Tp, size_t _ArrayExtent>
+ requires (__is_compatible_array<_Tp, _ArrayExtent>::value)
constexpr
span(array<_Tp, _ArrayExtent>& __arr) noexcept
: span(static_cast<pointer>(__arr.data()), _ArrayExtent)
{ }
- template<typename _Tp, size_t _ArrayExtent,
- typename = _Require<__is_compatible_array<_Tp, _ArrayExtent>>>
+ template<typename _Tp, size_t _ArrayExtent>
+ requires (__is_compatible_array<const _Tp, _ArrayExtent>::value)
constexpr
span(const array<_Tp, _ArrayExtent>& __arr) noexcept
: span(static_cast<pointer>(__arr.data()), _ArrayExtent)
{ }
- // NOTE: when the time comes, and P1394 -
- // range constructors for std::span - ships in
- // the standard, delete the #else block and remove
- // the conditional
- // if the paper fails, delete #if block
- // and keep the crappy #else block
- // and then cry that NB comments failed C++20...
- // but maybe for C++23?
-#ifdef _GLIBCXX_P1394
- private:
- // FIXME: use std::iter_reference_t
- template<typename _Iterator>
- using iter_reference_t = decltype(*std::declval<_Iterator&>());
- // FIXME: use std::ranges::iterator_t
- // N.B. constraint is needed to prevent a cycle when __adl_begin finds
- // begin(span) which does overload resolution on span(Range&&).
- template<typename _Rng,
- typename _Rng2 = remove_cvref_t<_Rng>,
- typename = enable_if_t<!__detail::__is_std_span<_Rng2>::value>>
- using iterator_t = decltype(std::__adl_begin(std::declval<_Rng&>()));
- // FIXME: use std::iter_value_t
- template<typename _Iter>
- using iter_value_t = typename iterator_traits<_Iter>::value_type;
- // FIXME: use std::derived_from concept
- template<typename _Derived, typename _Base>
- using derived_from
- = __and_<is_base_of<_Base, _Derived>,
- is_convertible<const volatile _Derived*, const volatile _Base*>>;
- // FIXME: require contiguous_iterator<_Iterator>
- template<typename _Iter,
- typename _Ref = iter_reference_t<_Iter>,
- typename _Traits = iterator_traits<_Iter>,
- typename _Tag = typename _Traits::iterator_category>
- using __is_compatible_iterator
- = __and_<derived_from<_Tag, random_access_iterator_tag>,
- is_lvalue_reference<_Ref>,
- is_same<iter_value_t<_Iter>, remove_cvref_t<_Ref>>,
- __is_compatible<remove_reference_t<_Ref>>>;
-
- template<typename _Range>
- using __is_compatible_range
- = __is_compatible_iterator<iterator_t<_Range>>;
-
public:
- template<typename _Range, typename = _Require<
- bool_constant<_Extent == dynamic_extent>,
- __not_<__detail::__is_std_span<remove_cvref_t<_Range>>>,
- __not_<__detail::__is_std_array<remove_cvref_t<_Range>>>,
- __not_<is_array<remove_reference_t<_Range>>>,
- __is_compatible_range<_Range>>,
- typename = decltype(std::__adl_data(std::declval<_Range&>()))>
+ template<ranges::contiguous_range _Range>
+ requires (_Extent == dynamic_extent)
+ && (!__detail::__is_std_span<remove_cvref_t<_Range>>::value)
+ && (!__detail::__is_std_array<remove_cvref_t<_Range>>::value)
+ && (!is_array_v<remove_reference_t<_Range>>)
+ && (__is_compatible_range<_Range>::value)
constexpr
span(_Range&& __range)
- noexcept(noexcept(::std::__adl_data(__range))
- && noexcept(::std::__adl_size(__range)))
- : span(::std::__adl_data(__range), ::std::__adl_size(__range))
+ noexcept(noexcept(ranges::data(__range))
+ && noexcept(ranges::size(__range)))
+ : span(ranges::data(__range), ranges::size(__range))
{ }
- template<typename _ContiguousIterator, typename _Sentinel, typename
- = _Require<__not_<is_convertible<_Sentinel, index_type>>,
- __is_compatible_iterator<_ContiguousIterator>>>
+ template<contiguous_iterator _ContiguousIterator,
+ sized_sentinel_for<_ContiguousIterator> _Sentinel>
+ requires (__is_compatible_iterator<_ContiguousIterator>::value)
+ && (!is_convertible_v<_Sentinel, size_type>)
constexpr
span(_ContiguousIterator __first, _Sentinel __last)
- : _M_extent(static_cast<index_type>(__last - __first)),
+ : _M_extent(static_cast<size_type>(__last - __first)),
_M_ptr(std::to_address(__first))
{
if (_Extent != dynamic_extent)
__glibcxx_assert((__last - __first) == _Extent);
}
- template<typename _ContiguousIterator, typename
- = _Require<__is_compatible_iterator<_ContiguousIterator>>>
+ template<contiguous_iterator _ContiguousIterator>
+ requires (__is_compatible_iterator<_ContiguousIterator>::value)
constexpr
- span(_ContiguousIterator __first, index_type __count)
+ span(_ContiguousIterator __first, size_type __count)
noexcept(noexcept(std::to_address(__first)))
: _M_extent(__count), _M_ptr(std::to_address(__first))
{ __glibcxx_assert(_Extent == dynamic_extent || __count == _Extent); }
-#else
- private:
- template<typename _Container,
- typename _DataT = decltype(std::data(std::declval<_Container&>())),
- typename _SizeT = decltype(std::size(std::declval<_Container&>()))>
- using __is_compatible_container
- = __is_compatible<remove_pointer_t<_DataT>>;
- public:
- template<typename _Container, typename = _Require<
- bool_constant<_Extent == dynamic_extent>,
- __not_<__detail::__is_std_span<remove_cv_t<_Container>>>,
- __not_<__detail::__is_std_array<remove_cv_t<_Container>>>,
- __not_<is_array<_Container>>,
- __is_compatible_container<_Container>>>
- constexpr
- span(_Container& __cont)
- noexcept(noexcept(std::data(__cont)) && noexcept(std::size(__cont)))
- : _M_extent(std::size(__cont)), _M_ptr(std::data(__cont))
- { }
-
- template<typename _Container, typename = _Require<
- bool_constant<_Extent == dynamic_extent>,
- __not_<__detail::__is_std_span<remove_cv_t<_Container>>>,
- __not_<__detail::__is_std_array<remove_cv_t<_Container>>>,
- __not_<is_array<_Container>>,
- __is_compatible_container<const _Container>>>
- constexpr
- span(const _Container& __cont)
- noexcept(noexcept(std::data(__cont)) && noexcept(std::size(__cont)))
- : _M_extent(std::size(__cont)), _M_ptr(std::data(__cont))
- { }
-
- constexpr
- span(pointer __first, index_type __count) noexcept
- : _M_extent(__count), _M_ptr(__first)
- { __glibcxx_assert(_Extent == dynamic_extent || __count == _Extent); }
-
- constexpr
- span(pointer __first, pointer __last) noexcept
- : span(__first, static_cast<index_type>(__last - __first))
- { }
-#endif // P1394
-
- template<typename _OType, size_t _OExtent, typename = _Require<
- __bool_constant<_Extent == dynamic_extent || _Extent == _OExtent>,
- is_convertible<_OType(*)[], _Type(*)[]>>>
+ template<typename _OType, size_t _OExtent>
+ requires (_Extent == dynamic_extent || _Extent == _OExtent)
+ && (__is_array_convertible<_Type, _OType>::value)
constexpr
span(const span<_OType, _OExtent>& __s) noexcept
: _M_extent(__s.size()), _M_ptr(__s.data())
// observers
- constexpr index_type
+ constexpr size_type
size() const noexcept
{ return this->_M_extent._M_extent(); }
- constexpr index_type
+ constexpr size_type
size_bytes() const noexcept
{ return this->_M_extent._M_extent() * sizeof(element_type); }
}
constexpr reference
- operator[](index_type __idx) const noexcept
+ operator[](size_type __idx) const noexcept
{
static_assert(extent != 0);
__glibcxx_assert(__idx < size());
}
constexpr span<element_type, dynamic_extent>
- first(index_type __count) const noexcept
+ first(size_type __count) const noexcept
{
__glibcxx_assert(__count <= size());
return { this->data(), __count };
}
constexpr span<element_type, dynamic_extent>
- last(index_type __count) const noexcept
+ last(size_type __count) const noexcept
{
__glibcxx_assert(__count <= size());
return { this->data() + (this->size() - __count), __count };
}
constexpr span<element_type, dynamic_extent>
- subspan(index_type __offset, index_type __count = dynamic_extent) const
+ subspan(size_type __offset, size_type __count = dynamic_extent) const
noexcept
{
__glibcxx_assert(__offset <= size());
span(const array<_Type, _ArrayExtent>&)
-> span<const _Type, _ArrayExtent>;
-#ifdef _GLIBCXX_P1394
-
- template<typename _ContiguousIterator, typename _Sentinel>
- span(_ContiguousIterator, _Sentinel)
- -> span<remove_reference_t<
- typename iterator_traits<_ContiguousIterator>::reference>>;
+ template<contiguous_iterator _Iter, typename _Sentinel>
+ span(_Iter, _Sentinel)
+ -> span<remove_reference_t<ranges::range_reference_t<_Iter>>>;
template<typename _Range>
span(_Range &&)
- -> span<remove_reference_t<typename iterator_traits<
- decltype(std::__adl_begin(::std::declval<_Range&>()))>::reference>>;
-
-#else
-
- template<typename _Container>
- span(_Container&) -> span<typename _Container::value_type>;
-
- template<typename _Container>
- span(const _Container&) -> span<const typename _Container::value_type>;
-
-#endif // P1394
+ -> span<remove_reference_t<ranges::range_reference_t<_Range&>>>;
template<typename _Type, size_t _Extent>
inline
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
-
+#endif // concepts
#endif // C++20
#endif // _GLIBCXX_SPAN