On 3/13/12 4:12 AM, Manu wrote:
I think I feel a sense of urgency towards the ABI aspect because it is a
breaking change, and I suspect the longer anything like that is left,
the less likely/more risky it becomes.
If it gets delayed for 6-12 months, are you honestly more or less likely
to say it's a good idea to fiddle with the ABI?
I think Walter could answer that.
I am sold on the Tuple approach now, so that's a big discussion that can
be dismissed.
Great!
Shall we discuss the shortcomings of his implementation? Can someone
demonstrate the details of his implementation?
From the little examples up in the thread, it looked like you could
only declare new variables inline, but not assign out to existing ones.
I'd say this needs to be added too, and perhaps that will throw the
whole design into turmoil? ;)
I thought more about it and we should be fine with two functions (untested):
enum Skip {};
@property ref Skip skip() {
static __gshared Skip result;
return result;
}
void scatter(T, U...)(auto ref T source, ref U targets) {
assert(source.length == targets.length);
foreach (i, ref target; targets) {
static if (is(typeof(target) != Skip)) {
target = source[i];
}
}
}
void gather(T, U...)(ref T target, auto ref U sources) {
assert(target.length == sources.length);
foreach (i, source; sources) {
static if (is(typeof(source) != Skip)) {
target[i] = source;
}
}
}
Usage:
auto t = tuple(1, "hi", 2.3);
int a;
string b;
double c;
t.scatter(a, b, skip); // assigns a and b from tuple
b = "!";
++c;
t.gather(skip, b, c); // assigns tuple from variables b and c
Andrei
