Regardless of what’s better, my comment was more about how they have a profiled and optimized method for include guards, but threw it all away for #pragma once.

Regardless of what’s better, my comment was more about how they have a profiled and optimized method for include guards, but threw it all away for #pragma once. If performance doesn’t matter because the optimizer is worse, then why’d they optimize include guards? My whole point is that something is not adding up with gcc’s implementation. It’s a fail on the authors’ parts, not mine.