As discussed in DConf2015: Python-like keyword arguments

[Michel Fortin via Digitalmars-d]

On 2015-05-31 04:08:33 +0000, ketmar <ketmar at ketmar.no-ip.org> said:

> my work now allows this:
>   string test (string a, string b=3D"wow", string c=3D"heh") {
>     return a~b~c;
>   }
> 
>   void main () {
>     enum str =3D test(c: "cc", a: "aa");
>     assert(str =3D=3D "aawowcc");
>   }

How does it handle overloading?

	string test(bool a, string b="wow", string c="heh") {}
	string test(bool a, string c="heh", bool d=true) {}

	test(a: true, c: "hi"); // ambiguous!

The irony of this example is that without argument names (or more 
precisely without reordering), there'd be no ambiguity here.


> and this:
>   void test(A...) (A a) {
>     import std.stdio;
>     foreach (auto t; a) writeln(t);
>   }
> 
>   void main () {
>     test(x: 33.3, z: 44.4, a: 9999, 7777, d:"Yehaw");
>   }

For that to be really useful the argument names should be part of the 
"A" type so you can forward them to another function and it still 
works. For instance:

	void test(string a, string b="wow", string c="heh") {}

	void forward(A...)(A a) {
		test(a);
	}

	void main() {
		forward(c: "cc", a: "aa");
	}


-- 
Michel Fortin
michel.fortin at michelf.ca
http://michelf.ca