how to instantiate explicitly template parameters in struct A(T1){this(T2)(){...}}

[Jonathan M Davis]

On Monday, May 13, 2013 13:27:44 Timothee Cour wrote:
> While writing DIP40, I came upon the following question:
> how to instantiate explicitly template parameters for both the
> class/struct AND the constructor?
> for example: struct A(T1){this(T2)(){...}} ? (T2 could be used
> somehow inside the ctor body for example)
> // auto a=A!double!int(); // CT error
> The example is a bit contrived but there could be less contrived ones
> where both A and ctor need explicit instantiations.

I don't believe that you can _ever_ give explicit template arguments to a 
constructor whether the type is templated or not. Note that this code doesn't 
compile:

struct S
{
 this(T)(T val)
 {
 }
}

void main()
{
 auto s = S!float(5);
}

and gives this error:

q.d(10): Error: template instance S!(float) S is not a template declaration, it 
is a struct
q.d(10): Error: template instance S!(float) S is not a template declaration, it 
is a struct

- Jonathan M Davis