The following is an error:
```
enum E : int;
E e = E(4);
```
enumbase.d(2): Error: cannot implicitly convert expression `4` of type `int` to `E`
Which is consistent with uniform construction because a base type instance does not implicitly convert to the enum type. But this compiles:
```
struct S {
this(int) {}
}
enum E : S;
E e = E(2);
```
However, an instance of S does not implicitly convert to E, so this is inconsistent.
The spec does not seem to mention enum construction with an argument list.
There is a test in dmd for issue 16346 to allow E(E.member), presumably for generic code.
Comment #1 by nick — 2024-11-09T17:28:53Z
There is also a dmd test case for issue 23778 using construction from base struct. So it would need to be deprecated.
Comment #2 by robert.schadek — 2024-12-13T19:38:27Z