foreach over string enum

[Jesse Phillips]

spir Wrote:

> On 02/10/2011 08:22 PM, Jesse Phillips wrote:

> > enum FileName : string {
> > file1 = "file1.ext",
> > file2 = "file2.ext"
> > }
> >
> > void main(string args[])
> > {
> >      foreach(a; __traits(allMembers, FileName))
> >          writeln(mixin("FileName." ~ a));
> > }
> 
> Why the mixin? Is it (just) to have the output string computed at compile-time?

The value of 'a' is the enum field name, not its value. The code will ultimately expand to:

void main() {
          writeln(FileName.file1));
          writeln(FileName.file2));
}

Which in turn will may have its enum contents expanded to the string value. The mixin is required because it is a named enum and 'a' is a string, not an alias:

      writeln(FileName.a)

doesn't work and nor does:

    writeln(FileName.mixin(a));