On 3/24/23 18:22, Oleksandr Koval wrote:
> No existing code uses "default:" for marking the default enum value
> because currently this syntax is invalid. So this is not a breaking
> change.
>
> Before this proposal:
> ExternalLibrary::Enum e{}; // e == 0
>
> After this proposal (and ExternalLibrary update):
> ExternalLibrary::Enum e{}; // e == some default value

The "ExternalLibrary update" is the breaking change here, not the
proposed core language extension.