Re: Return type deduction

[Patric via Digitalmars-d]

On Monday, 5 September 2016 at 09:59:16 UTC, Andrea Fontana wrote:
I asked this some time (years?) ago. Time for a second try :)
Consider this:

---

T simple(T)() { return T.init; }


void main()
{
        int test = simple!int(); // it compiles
        int test2 = simple();    // it doesn't
}

---

Is there any chance to implement this kind of deduction?
Please notice that it doesn't break any existing code, I guess.

For example using my json wrapper [1] this sounds a bit 
pedantic:

----
user.name = json.get!string("info/name");
user.age  = json.get!int("info/age");
----

If return type deduction could be implemented it would be:

----
user.name = json.get("info/name");
user.age  = json.get("info/age");
----

[1] https://code.dlang.org/packages/jsonwrap

Andrea

(I thought that i have see your idea in another lang, but maybe 
i´m wrong)

You can use ref, if you want to simplify your code;

void simple(T)( ref T t) { t = T.init; }

so maybe your example of the json can be something like this:

json.set(user.name,"info/name");

Or with some more little tricks:

alias json_set = json.set;
user.name.json_set("info/name");