deprecated enum and to!string warnings

[Vladimirs Nordholm]

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