std::extents<IndexType,Extents...>::extents - cppreference.com (original) (raw)
| constexpr extents() = default; | (1) | (since C++23) |
|---|---|---|
| template< class OtherIndexType, std::size_t... OtherExtents > constexpr explicit(/*see below*/) extents( const std::extents<OtherIndexType, OtherExtents...>& other ) noexcept; | (2) | (since C++23) |
| template< class... OtherIndexTypes > constexpr explicit extents( OtherIndexTypes... exts ) noexcept; | (3) | (since C++23) |
| template< class OtherIndexType, std::size_t N > constexpr explicit(N != rank_dynamic()) extents( std::span<OtherIndexType, N> exts ) noexcept; | (4) | (since C++23) |
| template< class OtherIndexType, std::size_t N > constexpr explicit(N != rank_dynamic()) extents( const std::array<OtherIndexType, N>& exts ) noexcept; | (5) | (since C++23) |
Construct an extents. One can construct extents from just dynamic extents, which are all the values getting stored, or from all the extents with a precondition.
Default constructor. Initializes all dynamic extents to zero.
Conversion from another
extentsobject. After construction, *this == other is true.
The behavior is undefined if
other.extent(r) != static_extent(r) for any r for which static_extent(r) represents a static extent, or
other.extent(r) is not representable as a value of type IndexType for any rank value r in other.
This overload participates in overload resolution only if
sizeof...(OtherExtents) == rank() is true, and
((OtherExtents == std::dynamic_extent || Extents == std::dynamic_extent ||
OtherExtents == Extents) && ...) is true.This constructor is explicit if
((Extents != std::dynamic_extent && OtherExtents == std::dynamic_extent) || ...) is true, or
std::numeric_limits<IndexType>::max() < std::numeric_limits<OtherIndexType>::max() is true.
- Let N be sizeof...(exts) and exts_arr be std::array<IndexType, N>{static_cast<IndexType>(std::move(exts))...}, equivalent to extents(exts_arr).
This overload participates in overload resolution only if
(std::is_convertible_v<OtherIndexTypes, IndexType> && ...) is true,
(std::is_nothrow_constructible_v<IndexType, OtherIndexTypes> && ...) is true, and
N == rank_dynamic() || N == rank() is true.
The behavior is undefined if
N != rank_dynamic() and exts_arr[r] is not equal to static_extent(r) for any r for which static_extent(r) represents a static extent, or
an element in exts is negative or not representable as a value of type IndexType.
4,5) If N equals rank_dynamic(), for all d in [0, rank_dynamic()), direct-non-list-initializes dynamic-extents[d] with std::as_const(exts[d]). Otherwise, for all d in [0, rank_dynamic()), direct-non-list-initializes _dynamic-extents_[d] with std::as_const(exts[dynamic-index-inv(d)]).
This overload participates in overload resolution only if
std::is_convertible_v<const OtherIndexType&, IndexType> is true,
std::is_nothrow_constructible_v<IndexType, const OtherIndexType&> is true, and
N == rank_dynamic() || N == rank() is true.
The behavior is undefined if
N != rank_dynamic() and exts[r] is not equal to static_extent(r) for any r for which static_extent(r) represents a static extent, or
exts[r] is negative or not representable as a value of type IndexType for any rank index r.
[edit] Parameters
| other | - | another extents to convert from |
|---|---|---|
| exts | - | represents the extents |