Multiple ChoiceIntermediate 45s
Union Active Member UB
Reading a member of a union other than the one most recently written (for non-common-initial-sequence types) is:
Options
- 1Well-defined and yields an unspecified value of the type of the member being read
- 2Undefined behavior (except for common initial sequence in standard-layout structs)
- 3A constraint violation that is diagnosed and rejected at compile time by the compiler
- 4Only undefined behavior if the union itself is non-trivial, otherwise it is fine
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