Can I set the base class like this?

[Jack]

On Tuesday, 26 January 2021 at 14:15:25 UTC, frame wrote:
> On Tuesday, 26 January 2021 at 04:39:07 UTC, Jack wrote:
>> note the body is the same, what changes is the base class. I'd 
>> like to avoid repeating myself when the body is the same and 
>> only the base class changes.
>
> You would have to call it with correct instantiation like
>
> alias Foo = C!(A!bool);
>
> Of course T!MyType would not work but I don't think you want 
> that anyway.
>
> It very depends on the use-case but just use a mixin where you 
> can pass any type you want from template constructor if you 
> don't want to repeat yourself:
>
>
> class MyType {
> }
>
> class A {
> }
>
> class B {
> }
>
> template base(T) {
>
>     static if (is(T : A)) {
>         bool doSomething() {
>             return true;
>         }
>     }
>     else static if (is(T : B)) {
>         bool doSomething() {
>             return false;
>         }
>     }
>     else {
>         void doSOmethingElse() {
>         }
>     }
> }
>
> class C(T1, T2) {
>     mixin base!T2;
>
>     T1 whatever() {
>         return new T1;
>     }
> }
>
> alias Foo = C!(MyType, A);
> alias Baa = C!(MyType, B);

Thank you! I find this approach rather elegant. Ability to pick 
the method to be part of the class' body without macros is really 
great.