On 02.08.2011 16:30, simendsjo wrote:
On 02.08.2011 14:22, Dmitry Olshansky wrote:
On 02.08.2011 16:18, simendsjo wrote:
On 02.08.2011 14:13, Dmitry Olshansky wrote:
On 02.08.2011 16:06, simendsjo wrote:
On 02.08.2011 13:55, Dmitry Olshansky wrote:
On 02.08.2011 15:06, simendsjo wrote:
The following program gives me
"Error: template t.S.__ctor(C) if(isSomeChar!(C)) conflicts with
constructor t.S.this at t.d(4)"
Is this because char etc can be converted to uint? Shouldn't the
template specification make this unambiguous?
import std.traits;
struct S {
this(uint i) {}
this(C)(C c) if(isSomeChar!C) {}
}
void main() {}
struct S {
this()(uint i) {}
this(C)(C c) if(isSomeChar!C) {}
}
should do it, though it (and workaround) looks like a bug to me.
With the empty templated this, I get other errors though:
"t.d(5): Error: constructor t.S.this conflicts with template
t.S.__ctor() at t.d(4)"
struct S {
this()(int a) {} // 4
this(int a, int b) {} // 5
}
Same logic here once you have template constructor, all others need to
be template, empty spec is a trick to get anything to be a
template. And
in this example you really do not need empty spec () in 4.
So my first example is a bug, and the second is a wrong error message?
Wondering what I should post in a potential bug report, and if it's
one or two bugs.
I think there is only one bug: template constructor (and functions IIRC)
can't be overloaded with non-template.
Both your examples show this bug, since this()(int a){} and this(C)(C c)
if(isSomeChar!C) {} are template constructors, while others are not.
I think the bug was there for quite some time and likely to be filed
already, so check Bugzilla first.
While changing ctors to templates, I came across another issue (bug?)
regarding assignment to immutable (and probably const) members from
templated ctors:
Error: can only initialize const member v inside constructor
Error: template instance t.S2.__ctor!() error instantiating
struct S {
immutable int v;
this(int v) {
this.v = v;
}
}
struct S2 {
immutable int v;
this()(int v) {
this.v = v;
}
}
void main() {
auto s = S(1); // ok
auto s2 = S2(1); // fails
}
Most definitely a bug, you seem to hit a lot of 'em recently :)
--
Dmitry Olshansky
