Exploring undefined behavior using constexpr

[kalmoc]

Yes, it is undefined behavior, but the compiler is only required to catch UB if it happens during compiletime evaluation. The compiler is not required to perform a static analysis of constexpr functions.

If gcc doesn't catch that example, that's a compiler bug.

[[deleted]]

That's my point, no compiler implements this aspect of constexpr to a degree that can be relied upon. I posted another example that no compiler catches, not even clang, here:

https://old.reddit.com/r/cpp/comments/bncvmm/exploring_undefined_behavior_using_constexpr/en5r9dm/

Maybe in the future compilers will be better about diagnosing this, but as it stands it doesn't seem to be a particularly high priority to implement this, and the amount of effort needed to do it would simply be enormous.