[Bug libstdc++/100070] Standard library container iterator-pair constructors should check C++20 iterator concepts

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100070

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
We want to do the same thing in insert and assign too. And in std::deque.