Ok signals work fine, until I use them in a descendant class.

Snippet:
-----------------
import std.signals;

class ClassA
{
	public mixin Signal!(int) addNumber1;
}

class ClassB : ClassA
{
	public mixin Signal!(int) addNumber2;
}

Error:
\dmd2\src\phobos\std\signals.d(0,0): Error: function main.ClassB.Signal!(int).emit cannot override final function main.ClassA.Signal!(int).emit (moooo)


Is this expected behavior or a bug in my code?

On Saturday, 23 February 2013 at 17:01:48 UTC, Damian wrote:
> Ok signals work fine, until I use them in a descendant class.
>
> Snippet:
> -----------------
> import std.signals;
>
> class ClassA
> {
> 	public mixin Signal!(int) addNumber1;
> }
>
> class ClassB : ClassA
> {
> 	public mixin Signal!(int) addNumber2;
> }
>
> Error:
> \dmd2\src\phobos\std\signals.d(0,0): Error: function main.ClassB.Signal!(int).emit cannot override final function main.ClassA.Signal!(int).emit (moooo)
>
>
> Is this expected behavior or a bug in my code?

I think this is a known issue. Here is a workaround I've used:


import std.signals;

struct MySignal(T)
{
    mixin Signal!T _signal;
    alias _signal this;
}

class ClassA
{
    MySignal!int addNumber1;
}

class ClassB : ClassA
{
    MySignal!int addNumber2;
}

void main()
{
    auto a = new ClassA;
    auto b = new ClassB;
    a.addNumber1.emit(1);
    b.addNumber1.emit(1);
    b.addNumber2.emit(1);
}

On Saturday, 23 February 2013 at 23:39:19 UTC, cal wrote:
> On Saturday, 23 February 2013 at 17:01:48 UTC, Damian wrote:
>> Ok signals work fine, until I use them in a descendant class.
>>
>> Snippet:
>> -----------------
>> import std.signals;
>>
>> class ClassA
>> {
>> 	public mixin Signal!(int) addNumber1;
>> }
>>
>> class ClassB : ClassA
>> {
>> 	public mixin Signal!(int) addNumber2;
>> }
>>
>> Error:
>> \dmd2\src\phobos\std\signals.d(0,0): Error: function main.ClassB.Signal!(int).emit cannot override final function main.ClassA.Signal!(int).emit (moooo)
>>
>>
>> Is this expected behavior or a bug in my code?
>
> I think this is a known issue. Here is a workaround I've used:
>
>
> import std.signals;
>
> struct MySignal(T)
> {
>     mixin Signal!T _signal;
>     alias _signal this;
> }
>
> class ClassA
> {
>     MySignal!int addNumber1;
> }
>
> class ClassB : ClassA
> {
>     MySignal!int addNumber2;
> }
>
> void main()
> {
>     auto a = new ClassA;
>     auto b = new ClassB;
>     a.addNumber1.emit(1);
>     b.addNumber1.emit(1);
>     b.addNumber2.emit(1);
> }

That solution is ok for 1 argument but for many arguments it wont suffice.

This is issue 5028.

On Sunday, 24 February 2013 at 17:30:14 UTC, Damian wrote:
> That solution is ok for 1 argument but for many arguments it wont suffice.
>
> This is issue 5028.

What is the problem with many arguments? I'm probably misunderstanding, but e.g. this works:

struct MySignal(T...)
{
    mixin Signal!T _signal;
    alias _signal this;
}

class A
{
    MySignal!(float, int[]) sigA;
}

class B : A
{
    MySignal!(int, string, char) sigB;
}

void main()
{
    auto a = new A;
    auto b = new B;
    a.sigA.emit(1.4, [1,2,3]);
    b.sigA.emit(1, [4,5,6]);
    b.sigB.emit(1, "hello", 'x');
}

On Sunday, 24 February 2013 at 19:20:06 UTC, cal wrote:
> On Sunday, 24 February 2013 at 17:30:14 UTC, Damian wrote:
>> That solution is ok for 1 argument but for many arguments it wont suffice.
>>
>> This is issue 5028.
>
> What is the problem with many arguments? I'm probably misunderstanding, but e.g. this works:
>
> struct MySignal(T...)
> {
>     mixin Signal!T _signal;
>     alias _signal this;
> }
>
> class A
> {
>     MySignal!(float, int[]) sigA;
> }
>
> class B : A
> {
>     MySignal!(int, string, char) sigB;
> }
>
> void main()
> {
>     auto a = new A;
>     auto b = new B;
>     a.sigA.emit(1.4, [1,2,3]);
>     b.sigA.emit(1, [4,5,6]);
>     b.sigB.emit(1, "hello", 'x');
> }

Oooh I could of sworn I tried that.. it was late and I was defining
MySignal as a mixin still!! My bad! Your workaround does indeed work.
Thanks.