[Bug libstdc++/107761] Implement C++23 <mdspan>

["cooky.ykooc922 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107761

--- Comment #5 from Desmond Gold <cooky.ykooc922 at gmail dot com> ---
when I mentioned being "inspired by," I was referring to drawing guidance from
existing reference implementations like libc++, STL, and Kokkos for the
<mdspan> implementation in libstdc++. Specifically, for how they implement the
preconditions and layout_stride. I apologize for not explicitly defining what I
meant by "inspiration" earlier. However, it's important to note that my work
primarily adheres to the standards' definitions rather than directly
replicating code. This approach ensures alignment with the intended
functionality while respecting authorship, copyright, and licensing concerns.
From the link you've checked out, you'll notice the implementation is still a
work in progress. It's incomplete and would greatly benefit from additional
feedback to incorporate the missing elements :>