Template to retrieve compile-time enum member from run-time enum member?

[Timoses]

Bumped across another problem : /

```
import std.stdio;

enum menum { A, B, C }

void main()
{
    foo(menum.A);
}

void foo(menum e)
{
     writeln(instantiateWith!Temp(e));
}

auto instantiateWith(alias Fn, T)(T x)
     if (is(T == enum))
{
     switch (x)
     {
         import std.traits : EnumMembers;
         static foreach (e; EnumMembers!T)
             case e:
                 return Fn!e;
         default:
             assert(false);
     }
}

template Temp(menum e)
{
     struct TempStruct { uint i; };
     TempStruct Temp;

     shared static this()
     {
         static if (e == menum.A)
             Temp.i = 3;
     }

}
```

now returns:
source\app.d(25,17): Error: mismatched function return type 
inference of `TempStruct` and `TempStruct`
source\app.d(12,33): Error: template instance 
`app.instantiateWith!(Temp, menum)` error instantiating
dmd failed with exit code 1.

It's the same return type... so why the error?