[libcxx-commits] [libcxx] [libc++] Optimize string operator[] for known large inputs (PR #69500)

[Louis Dionne via libcxx-commits]

ldionne wrote:

> And what about for non-constant string indexes?

Right, in this case `__builtin_constant_p` will evaluate to `false`, so it is extremely unlikely that the compiler will generate any code for the `if` branch. Basically this seems to be a free optimization.

https://github.com/llvm/llvm-project/pull/69500