[Bug libstdc++/108846] std::copy, std::copy_n and std::copy_backward on potentially overlapping subobjects

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108846

--- Comment #18 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Created attachment 54537
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54537&action=edit
libstdc++: Do not use memmove for 1-element ranges [PR108846]

This is a more complete patch that passes Arthur's test in comment 0.