digitalmars.D - opCall and template functions
- Steve Teale (30/30) May 21 2009 Is this error intentional
- Jarrett Billingsley (7/37) May 21 2009 n strange.A.opCall at strange.d(8)
- Steve Teale (4/15) May 22 2009 Jarrett,
Is this error intentional import std.stdio; class A { int a; double b = 22.4; string s = "whatever"; string opCall() { return s; } //T opCall(T = string)() { return cast(T) s; } T opCall(T)(T* dummy) { if (is(typeof(dummy) : int*)) return cast(T) a; else return cast(T) b; } } double* D; int* I; void main() { A a = new A(); double d = a(D); writefln("d = %f", d); int n = a(I); writefln("n = %d", n); writefln(a()); } strange.d(10): Error: template strange.A.opCall(T) conflicts with function strange.A.opCall at strange.d(8) You can make it work with the template version of opCall with no args
May 21 2009
On Thu, May 21, 2009 at 10:01 AM, Steve Teale <steve.teale britseyeview.com> wrote:Is this error intentional import std.stdio; class A { =A0 int a; =A0 double b =3D 22.4; =A0 string s =3D "whatever"; =A0 string opCall() { return s; } =A0 //T opCall(T =3D string)() { return cast(T) s; } =A0 T opCall(T)(T* dummy) =A0 { =A0 =A0 =A0if (is(typeof(dummy) : int*)) =A0 =A0 =A0 =A0 return cast(T) a; =A0 =A0 =A0else =A0 =A0 =A0 =A0 return cast(T) b; =A0 } } double* D; int* I; void main() { =A0 A a =3D new A(); =A0 double d =3D a(D); =A0 writefln("d =3D %f", d); =A0 int n =3D a(I); =A0 writefln("n =3D %d", n); =A0 writefln(a()); } strange.d(10): Error: template strange.A.opCall(T) conflicts with functio=n strange.A.opCall at strange.d(8)You can make it work with the template version of opCall with no argsI doubt it's intentional, but that's always been the workaround. One of the things Walter said he wanted to do for D2 was to make it possible to overload templated and normal functions like this, but that sadly hasn't materialized yet.
May 21 2009
Jarrett Billingsley Wrote:On Thu, May 21, 2009 at 10:01 AM, Steve Teale <steve.teale britseyeview.com> wrote:Jarrett, I can see just intuitively that it could be one of those difficult things to do, so I'll continue with the workaround, and live in hope. But I do appreciate the intention. SteveIs this error intentional strange.d(10): Error: template strange.A.opCall(T) conflicts with function strange.A.opCall at strange.d(8) You can make it work with the template version of opCall with no argsI doubt it's intentional, but that's always been the workaround. One of the things Walter said he wanted to do for D2 was to make it possible to overload templated and normal functions like this, but that sadly hasn't materialized yet.
May 22 2009