Per ISO C++ standard 9.7.1 5.3,
"Otherwise the type of the enumerator is the same as that of the preceding enumerator unless the
incremented value is not representable in that type, in which case the type is an unspecified integral
type sufficient to contain the incremented value. If no such type exists, the program is ill-formed."
it is not undefined behavior to set a scoped enum to a value outside of its constant range because all values of the underlying type can represent the scoped enum
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