On Thu, Mar 25, 2010 at 03:34:06PM -0400, Nick Sabalausky wrote:
> I haven't used opDispatch, and don't remember much from the discussions of
> it, so pardon a possibly dumb question: Would that prevent you from getting
> a (meaningful) compile-time error if you mis-typed one of the flags?
A static assert would fire if the flag name given isn't in its internal table.
The opDispatch function takes a string. It'd look something like this:
====
import std.stdio;
struct Flags(T) {
int opDispatch(string name)() {
foreach(item; itemList) {
if(name == item.name)
return item.value;
}
static assert(0, "No such member: " ~ name);
}
struct Item {
string name;
T value;
}
Item[] itemList;
}
void main() {
Flags!int a;
int b = a.what;
}
===
$ dmd -c test.d
test.d(10): Error: static assert "No such member: what"
The actual implementation of the Flags struct would be different to keep
it all compile time (and of course, offer a constructor of sorts), but this
show the idea and the error you can get.
--
Adam D. Ruppe
http://arsdnet.net
