How to get value of type at CT given only an alias

[Moritz Maxeiner via Digitalmars-d-learn]

On Friday, 14 July 2017 at 18:06:49 UTC, Steven Schveighoffer 
wrote:
>
> .init is the default value.
>
> I'm not sure you can get the default value of a non-default 
> initializer, My attempts using init didn't work. e.g.:
>
> void foo(alias T)()
> {
>    pragma(msg, T.init);
> }
>
> struct S
> {
>    int y = 5;
>    void bar() { foo!y; } // prints 0
> }

See spec [1]:

"If applied to a variable or field, it is the default initializer 
for that variable or field's type."

If you want to get at the 5 in a static context, you'd have to use

---
S.init.y
---

i.e. get the default initializer for the struct and get its y 
member's value.

[1] https://dlang.org/spec/property.html#init