Prevent default-initialised struct

[BCS]

Hello Daniel,

> Hi all,
> 
> is there any way to prevent a struct from being created directly?
> Basically, I want to prevent this:
> 
> {
> non_null!(T) a;
> }
> I want people to have to use provided functions to create a structure:
> 
> {
> auto a = non_null!(T)(new T);
> }
> -- Daniel
> 

struct S { private static S opCall(); } //???