NAME¶

std::extents::extents - std::extents::extents

Synopsis¶

constexpr extents() = default; (1) (since C++23)
template< class OtherIndexType, std::size_t... OtherExtents >

constexpr explicit(/*see below*/) (2) (since C++23)

extents( const std::extents<OtherIndexType, OtherExtents...>&
other ) noexcept;
template< class... OtherIndexTypes > (3) (since C++23)
constexpr explicit extents( OtherIndexTypes... exts ) noexcept;
template< class OtherIndexType, std::size_t N >

constexpr explicit(N != rank_dynamic()) (4) (since C++23)

extents( std::span<OtherIndexType, N> exts ) noexcept;
template< class OtherIndexType, std::size_t N >

constexpr explicit(N != rank_dynamic()) (5) (since C++23)

extents( const std::array<OtherIndexType, N>& exts ) noexcept;

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.

1) Default constructor. Initializes all dynamic extents to zero.
2) Conversion from another extents object. 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.
3) 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.

Parameters¶

other - another extents to convert from
exts - represents the extents

Example¶

This section is incomplete
Reason: no example

See also¶

This section is incomplete

Categories:¶

* Todo no example
* Todo without reason