Template argument deduction and default args

[Jakob Ovrum via Digitalmars-d]

On Thursday, 24 July 2014 at 07:01:09 UTC, Manu via Digitalmars-d 
wrote:
> I imagine that would be a compile error; the static if can't be 
> resolved
> without knowing T, and prior to resolution of the static if, no
> constructors exist.

Please lay out this kind of logic in a DIP so it can actually be 
implemented. As I said in the enhancement request, the problem is 
defining the feature for the general case; that means defining it 
so the compiler knows how to proceed in all cases (including when 
to error). If we can't define this robustly it will become a pain 
in the ass for both users and compiler-writers.