[libcxx-commits] [libcxx] [libc++] Remove usage of internal string function in sstream (PR #75858)

[Louis Dionne via libcxx-commits]

https://github.com/ldionne approved this pull request.

This LGTM. The performance should be very similar, since in both cases we end up having to move characters around (specifically `[pos, view.size())` to the beginning of the result).

https://github.com/llvm/llvm-project/pull/75858