[PATCH] D27022: [libcxx] [test] Fix MSVC warning C4389 "signed/unsigned mismatch", part 9/12.

[Eric Fiselier via Phabricator via cfe-commits]

EricWF accepted this revision.
EricWF added a comment.
This revision is now accepted and ready to land.

LGTM.

I may have considered doing the cast to `ptrdiff_t` for the other operand instead of the `size_t` cast, but IDK which is better.


https://reviews.llvm.org/D27022