std::extents<IndexType,Extents...>::dynamic-index
Min standard notice:
Returns the number of dynamic extents below index i. If i <= rank() is false, the behavior is undefined.
# Declarations
private:
static constexpr auto /*dynamic-index*/( rank_type i ) noexcept;
(since C++23) (exposition only*)
# Parameters
i: the index
# Return value
The number of Er with r < i for which Er is a dynamic extent.