On Sun, Mar 07, 2010 at 12:36:11AM +0000, Michal Minich wrote:
> I never used opAssign, but doesn't it solves this problem? Considering
> that both opCall and opAssign work with "=" their interaction must be
> probably quite complex...
opAssign only worked after the struct has been initialized.
===
import std.stdio;
struct S {
/*
static S opCall(int a) {
S tmp;
writefln("opCall(%d);", a);
return tmp;
}
*/
S* opAssign(int a) {
writefln("opAssign(%d);", a);
return &this;
}
}
void main() {
S a = 10; // Error: cannot implicitly convert expression (10) of type
int to S
a = 20;
a(30);
}
===
Uncomment the opCall, and it compiles, outputting:
opCall(10);
opAssign(20);
opCall(30);
If you add a second opCall that is not static, but otherwise identical,
then it fails to compile either the first nor third lines, because:
c.d(19): Error: function c.S.opCall called with argument types:
((int))
matches both:
c.S.opCall(int a)
and:
c.S.opCall(int a)
c.d(21): Error: function c.S.opCall called with argument types:
((int))
matches both:
c.S.opCall(int a)
and:
c.S.opCall(int a)
(one being the static opCall, and the other of course being the instance one).
Pretty annoying. This is the #1 thing that got in my way of creating a
JavascriptObject struct right after opDispatch came out - emulating a
delegate and accepting assignment at declaration were mutually incompatible.
--
Adam D. Ruppe
http://arsdnet.net
