Return enum-templated struct based on runtime value

[Sebastian Graf]

Hi,

I wonder if there is a good way to dry up this:

     enum Machine
     {
         I386,
         AMD64
         // , ...
     }

     template machineWord(Machine machine)
     {
         static if (machine == Machine.I386)
         {
             alias machineWord = uint;
         }
         static if (machine == Machine.AMD64)
         {
             alias machineWord = ulong;
         }
     }

     ulong foo(Machine machine)
     {
         if (machine == Machine.I386)
         {
             machineWord!(Machine.I386) m = (1 << 32)-1;
             m++;
             return m;
         }
         else // assume AMD64
         {
             machineWord!(Machine.AMD64) m = (1 << 32)-1;
             m++;
             return m;
         }
     }

Essentially, I am doing the same with each machine type, but it 
has different semantics for each of them. I hope you see this is 
a valid use case and a way to remove duplication.
Something à la specify the enum members to switch on to a 
template together with a templated function and then do some 
compile time magic to expand the code to invoke the appropriate 
specialization.