January 23, 2019
https://issues.dlang.org/show_bug.cgi?id=19605

          Issue ID: 19605
           Summary: enum X: "Error: enum X is forward referenced when
                    looking for sizeof"
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: elpenguino+D@gmail.com

Very easy to reproduce:
```
enum X;
static assert(X.sizeof == 0);
```

Note that I'm not exactly sure what the size of this should be. My guess was 0, but DMD 2.064 seems to manage to evaluate it to 4 despite still issuing the same error.

--