Member predicate OverridableCallable::getAnOverrider

Gets a callable defined in a sub type of t (which is itself a sub type of this callable’s declaring type) that overrides/implements this callable, if any.

The type t may be a constructed type: For example, if t = C<int>, then only callables defined in sub types of C<int> (and e.g. not C<string>) are valid. In particular, if C2<T> : C<T> and C2 contains a callable that overrides this callable, then only if C2<int> is ever constructed will the callable in C2 be considered valid.