On 03/11/2012 09:41 PM, Manu wrote:
On 11 March 2012 20:57, Andrei Alexandrescu
...
Regarding low-level efficiency, the main issue is that structs and
function argument lists have distinct layouts. Consider:
import std.stdio, std.typecons;
int a(int b, int c) {
return b + c;
}
auto foo() {
return tuple(1, 1);
}
void main() {
writeln(a(foo().expand));
}
An adjustment may be needed from the output of a() to the arguments
of foo(). (Probably not in this case.) I understand that someone
very concerned with low-level performance would scrutinize such code
carefully.
Wow, I can't imagine how '.expand' could possibly work :) .. that looks
like total magic. A parameter list can be populated by items collected
in a tuple via a property?
The property is a built-in tuple. :)
Tuple's implementation is not a lot more complicated than this:
struct Tuple(T...){
T expand;
alias expand this;
}
// 'magic' already available
int a(int b, int c){
return b+c;
}
void main(){
auto tuple = Tuple!(int, int)(1,2);
writeln(a(tuple.expand));
}
