Alias Expressions

[Xinok]

I know this has probably been asked for a hundred times before, 
but I don't understand why D doesn't support this. Template alias 
parameters can accept nearly anything as an argument that 
standard aliases don't. I think standard aliases should be 
equally as powerful as their template counterpart.

If you can write this:
template Eval(alias arg){ alias arg Eval; }
alias Eval!(cond ? a : b) al;

Why not simply allow this?
alias (cond ? a : b) al;

Or perhaps this:
alias al = cond ? a : b;