Re: Template constructor in a non-template struct.

[bearophile via Digitalmars-d-learn]

ChrisG:

I don't really understand how I'd differentiate a constructor 
template from a class/struct template.

One solution is to use a template struct (struct/class names 
start with an upper case in D, while typed enum members usually 
start with a lower case):


enum E { option1, option2 }

struct Boring(E Opt = E.option1) {
    this(int arg1, int arg2) {}
}

void main() {
    auto a = Boring!(E.option2)(1, 2);
}


If you want to instantiate the constructor template without type 
inference, then this seems to work, but it's not idiomatic D:


enum E { option1, option2 }

struct Boring {
    this(E Opt = E.option1)(int arg1, int arg2) {}
}

void main() {
    auto a = Boring().__ctor!(E.option2)(1, 2);
}


Bye,
bearophile