Comment by ryao

My comment had been meant for C, but it should apply to C++ too even when operator overloading is used, provided the comparisons are simple and inlined. If you add overloads for the > and < operators in your string example to a place where they would inline, and the overload compares .length(), this should simplify. For example, godbolt shows that CMP(X, Y) == 0 is optimized to one mov instruction and one cmp instruction despite operator overloads when I implement your string example:

https://godbolt.org/z/nGbPhz86q

If you did not inline the operator overloads and had them in another compilation unit, do not expect this to simplify (unless you use LTO).

If you have compound comparators in the operator overloads (such that on equality in one field, it considers a second for a tie breaker), I would not expect it to simplify, although the compiler could surprise me.