The C++ standard calls these "ill-formed, no dioagnosrics required" instead of UB, although it's not always consistent. It is indeed more or less "translation-t

The C++ standard calls these "ill-formed, no dioagnosrics required" instead of UB, although it's not always consistent. It is indeed more or less "translation-time UB". The difference is exactly that affected lines don't need to be in the execution path to make all executions undefined, and that the compiler/linker may fail the translation.