std::layout_stride::mapping<Extents>::required_span_size

constexpr index_type required_span_size() const noexcept;

(since C++23)

Returns the required size of the mapping.

Let s be equal to:

1, if extents().rank() == 0 is true,
otherwise, 0, if the size of the multidimensional index space extents() is 0,
otherwise, 1 plus the sum of products of extents().extent(r) - 1 and extents_type::index-cast(strides_[r]) for all r in the range [0, extents().rank()).

A call is equivalent to return s;.

The required size of the mapping.

required_span_size	returns the required size of the mapping (public member function of `std::layout_left::mapping<Extents>`)
required_span_size	returns the required size of the mapping (public member function of `std::layout_right::mapping<Extents>`)
size	returns the size of the multidimensional index space (public member function of `std::mdspan<T,Extents,LayoutPolicy,AccessorPolicy>`)

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