On Monday, 24 September 2012 at 10:53:47 UTC, comco wrote:
Yes, I don't claim that - the last thing is just nasty. It's
just playing with constructs seeing how far can we go. By the
way, now I use the reassign function all over the place! I'm
also very glad this discussion ends with a (remotely connected)
bug report!
Oh. I think I just got what your "reassign" was meant to do. I
think I see it now. I guess it does work nice actually.
I'd say that unfortunately, your *new* reassign is making the
assumption that it is possible to grab a reference of the passed
in objects. It will fail with "write properties", that need to
evaluate different functions depending on read context and write
context:
--------
import std.stdio;
void reassign(A...)(ref A a) { //L3
static if (A.length > 1) {
a[0] = a[1];
reassign(a[1 .. $]);
}
}
struct S
{
private int i;
@property int x(){return i;}
@property int x(int v){return i = v;}
}
void main()
{
S a = S(1);
S b = S(2);
S c = S(3);
a.x = b.x;
b.x = c.x;
c.x = 4;
writefln("%s %s %s", a.x, b.x, c.x);
reassign(a.x, b.x, c.x, 5); //L27
writefln("%s %s %s", a.x, b.x, c.x);
}
--------
main.d(3): Error: template main.reassign(A...) cannot deduce
template function from argument types !()(int,int,int,int)
--------
You could get away with it with some sort of template string
mixin:
mixin ReassignMixin!("a.x", "b.x", "c.x", 5");
reassign();
The problem with this approach though, is that it only works once
per scope... and really, it is not much more than a glorified
macro.
