On Monday, 15 October 2018 at 16:46:34 UTC, Steven Schveighoffer
wrote:
On 10/15/18 12:40 PM, Márcio Martins wrote:
import std.stdio;
void incx(T, Args...)(ref T t) {
++t.x;
}
static struct Test(T) {
T x;
}
void main() {
Test!uint t;
t.incx(); // works
t.incx!(); // works
incx(t); // works
t.incx!(1, 2, 3); // what?
incx(t, 1, 2, 3); // what?
writeln(t.x);
}
test.d(16): Error: template test.incx cannot deduce function
from argument types !(1, 2, 3)(Test!uint), candidates are:
test.d(3): test.incx(T, Args...)(ref T t)
No, not a bug.
I suspect you want this?
void incx(Args..., T)(ref T t);
This doesn't seem to work, because:
test.d(3): Error: template `test.incx(Args..., T)(ref T t)`
template tuple parameter must be last one
Are you sure it's not a bug? It would be very un-intuitive
otherwise, no?
Considering that the declaration is legal, and that the template
parameter deduction works when Args.length == 0, but stops
working when Args.length > 0.
There seems to be no way around it, except manually specifying
the type, which is not only annoying.
I was trying to use UFCS to emulate a method on a family of
structs, but this makes it impossible :(
