How to determine if a function is implemented

[JS]

On Friday, 5 July 2013 at 06:34:58 UTC, Kenji Hara wrote:
> On Friday, 5 July 2013 at 01:27:06 UTC, JS wrote:
>> the code
>>
>> http://dpaste.dzfl.pl/25bfeeb7
>>
>> attempts to implement an interface. The current issue is that 
>> I need to determine if the user has added the member of the 
>> interface to the class or if the mixin needs to add it.
>>
>>
>> so the lines
>>
>> class B : A
>> {
>> 	A a;
>> 	
>> 	//void myfunc(float a, int b, string c) { };
>> 	//@property int myvalue() { return 4; }
>> 	mixin implementInterface!a;
>> }
>>
>> The mixin adds the two commented functions above it which 
>> effectively implement the interface A in B. The problem is, I 
>> might want to manually specify one, e.g.,
>>
>>
>> class B : A
>> {
>> 	A a;
>> 	
>> 	void myfunc(float a, int b, string c) { };
>> 	//@property int myvalue() { return 4; }
>> 	mixin implementInterface!a;
>> }
>>
>> So the mixin needs to be aware and not add a method that is 
>> already implemented.
>> I need some way for the mixin to distinguish the two cases 
>> above. e.g., isImplemented!(myfunc(float, int, string)) or 
>> something like that.
>
> It's completely unnecessary. A mixed-in function cannot 
> override properly declared function that has same name in the 
> mixed-in scope.
>
>
> interface I { int foo(); }
>
> mixin template Foo()
> {
>     override int foo() { return 1; }
> }
>
> class C1 : I {
>     mixin Foo!();
> }
>
> class C2 : I
> {
>     int foo() { return 10; }
>     mixin Foo!();
>     // mixed-in foo is not stored in vtbl
> }
>
> void main()
> {
>     assert(new C1().foo() == 1);
>     assert(new C2().foo() == 10);
> }
>
> Kenji Hara

Cool, now that you've pointed that out I do remember reading 
that. The code was working all along, the issue being d-ide 
saying that build failed and not producing a binary. I guess this 
solves that problem and I better implement the code.