Indexed foreach on struct?

H. S. Teoh hsteoh at quickfur.ath.cx
Mon Jan 23 13:32:20 PST 2012


On Mon, Jan 23, 2012 at 01:16:29PM -0800, H. S. Teoh wrote:
> On Mon, Jan 23, 2012 at 03:32:07PM -0500, Matt Soucy wrote:
> > So I was messing around with some code I've been writing recently,
> > and I wanted to use a foreach on a struct as if it were an
> > associative array. The problem is, I can't find any information on
> > how to do that.
[...]

Oops, missed the part about associative arrays. For that, you can simply
add more arguments to the delegate, for example:

	struct Test {
		int opApply(int delegate(ref int, ref int) dg) {
			auto ret = 0;
			for (auto i=0; ret==0 && i<5; i++) {
				auto j = i+10;
				ret = dg(i, j);
			}
			return ret;
		}
	}

	import std.stdio;
	void main() {
		Test t;

		foreach (n, m; t) {
			writeln(n, " ", m);
		}
	}


T

-- 
"I suspect the best way to deal with procrastination is to put off the
procrastination itself until later. I've been meaning to try this, but
haven't gotten around to it yet. " -- swr


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