On Thursday, 17 September 2020 at 21:05:59 UTC, 60rntogo wrote:
struct V
{
int x;
mixin assign!"+";
// mixin assign!"-";
}
However, if I uncomment the second mixin, there is an error "v
is not a scalar, it is a V". I guess I somehow need to merge
these overloads, but I don't know how.
Usually, that would be:
struct V {
int x;
mixin assign!"+" a;
mixin assign!"-" b;
alias opOpAssign = a.opOpAssign;
alias opOpAssign = b.opOpAssign;
}
However, I can't seem to get that working. It seems to be an
instance of this issue:
https://issues.dlang.org/show_bug.cgi?id=18118
Note that explicitly calling the methods does work:
v.opOpAssign!"-"(v);
v.opOpAssign!"+"(v);
I don't know any good workarounds for this, you'll probably have
to write a separate opOpAssign method for V that performs the
forwarding to the mixed-in methods. This is, to put it very
nicely, not an optimal solution.
btw, I'm somewhat surprised by your use of a template this
parameter
(https://dlang.org/spec/template.html#template_this_parameter).
Generally this will work, but you're probably better off with
ref auto opOpAssign(string op)(typeof(this) rhs) if (op ==
op_)
--
Simen
