Unreachable warning is annoying

[Yuxuan Shui]

See this simple example:

int staticFind(T, S...)() {
     foreach(id, R; S) {
         if (is(T == R))
             return id;
         }
     }
     return -1;
}

staticFind!(int, int, double) will generate a 'statement is 
unreachable' warning, and staticFind!(int, double) won't.

This behaviour is understandable, but annoying. If template 
writer cares about this unreachable warning, they basically can't 
use any early return at all.

So previous example has to be re-written into:

int staticFind(T, S...)() {
     int ret = -1;
     foreach(id, R; S) {
         if (is(T == R) && ret == -1)
             ret = id;
         }
     }
     return ret;
}

However, this might not always be so simple in more complex 
functions. And this could potentially increase compilation time 
(maybe?).