deprecated enum and to!string warnings

[Steven Schveighoffer]

On 11/19/18 2:47 PM, Vladimirs Nordholm wrote:
> The following code produces 28 deprecation warnings at build time:
> 
>      import std.conv : to;
> 
>      enum Foo {
>          bar,
>          deprecated baz
>      }
> 
>      void main() {
>          to!string(Foo.bar);
>      }
> 
> Why is that?
> 
> https://run.dlang.io/is/AdUscN

Ouch!

I don't know if there's a way to fix this, what I think is happening is 
there are multiple instantiations of the same template from different 
places, and each time it's used, it's going to cause a warning.

The reason you see it, even though "baz" isn't used, is likely because 
of the way to!string works for enums (it probably uses a switch with all 
the enum values as cases).

-Steve