std::extents<IndexType,Extents...>::rank
Min standard notice:
Returns the number of dimensions in extents.
# Declarations
static constexpr rank_type rank() const noexcept;
(since C++23)
# Return value
The number of dimensions.
# Example
#include <iostream>
#include <mdspan>
int main()
{
std::extents<int, 1, 2> e1;
std::extents<int, 3, 4, std::dynamic_extent> e2(5);
std::cout << e1.rank() << ", " << e2.rank() << '\n';
}