I'm struggling with generics here. sorry for how c...

# getting-started

[y]

I'm struggling with generics here.
sorry for how contrived this is, but

sealed class Foo {  
    class A(): Foo()  
    class B(): Foo()
    class C(): Foo()
}

class Bar<F: Foo>(val f: F) { }

inline fun <F : Foo,  reified RET : Bar<F>> doSomething(): List<RET> { //... }

now this is fine and I can call it with doSomething<F, Bar<F>>(), or I can make the function signature inline fun <reified RET : Bar<Foo>> doSomething(): List<RET>, and then call it with doSomething<Bar<F>>.
but what I'd really like to do is call it with doSomething<F>(). is this possible?

[Adam S]

are you sure you need to define RET as a type parameter? It seems like since Bar is not open or abstract, you can just use Bar

inline fun <F : Foo> doSomething(): List<Bar<F>> { TODO() }

[y]

unless I'm missing something, I do - at some point in doSomething(), I have to do someVar is RET. which makes Kotlin complain that I'm checking for an instance of an erased type.

[Adam S]

well, now that I think about it, perhaps Bar doesn’t need to be generic? Foo is always constrained to A, B, or C, so making Bar generic actually makes the typing less strict

class Bar(val f: Foo) { }

inline fun <F : Foo> doSomething(): List<Bar> { //... }

[y]

I'll give it a try. unfortunately, the class definitions are mostly not my code.
otherwise I guess calling it with doSomething<Bar<F>>() is really not that bad.