Comment by tialaramex

> Which set of semantics is honored?

Typically it's configurable. For example C++ 26 seems to be intending you'll pick a compiler flag to say if you want its do-nothing semantics, or its "tell me about the problem and press on" semantics or just exit immediately and report that. They're not intending (in the standard at least) to have the assume semantic because that is, as you'd expect, controversial. Likewise more fine-grained configuration they're hoping will be taken up as a vendor extension.

My understanding is that C3 will likely offer the coarse configuration as part of their ordinary fast versus safe settings. Do I think that's a good idea? No, but that's definitely not "Unknown".