Template params: decl vs instantiation syntax

[Daniel Gibson]

Nick Sabalausky schrieb:
> A trivial thing, but something I've been wondering about for awhile:
> 
> Function parameter syntax:
>     Declare: foo(bar)
>     Call: foo(bar)
> 
> Template parameter syntax in C++/C#/etc:
>     Declare: foo<bar>
>     Instantiate: foo<bar>
> 
> Template parameter syntax in D:
>     Declare: foo(bar)
>     Instantiate: foo!(bar)
> 
> Why the difference in syntax between declaring and instantiating? Why not 
> use the exclamation for declaration too? Would that create a grammar 
> ambiguity? Some other reason? No particular reason?
> 
> Obviously it's not a big issue, just curious.
> 
> 

because:

import std.stdio;

void fun(int X=3)(int a = 4){
	writefln("X==%s a==%s", X, a);
}

void main() {
	fun!(1)(2); // X==1, a==2
	fun(2); // X==3, a==2
	fun!(2); // X==2, a==4
}


Cheers,
- Daniel