Function Reference injection doesn't work unless provided type is specified explicitly

If I want to inject a function reference into a class, the build fails unless I explicitly specify the provided type for the function reference in the component. Without the return type, it defaults to the behaviour of trying to generate a provider and in the following example complains that Any can’t be provided.

i.e.
this does not work:

@Inject
class MyClass(private val myProvider: suspend () -> Any)

suspend fun theProvider(): Any { /* ... */ }

@Component
abstract class AppComponent {
  @Provides
  protected fun provideTheProvider() = ::theProvider
}

but this does:

@Inject
class MyClass(private val myProvider: suspend () -> Any)

suspend fun theProvider(): Any { /* ... */ }

@Component
abstract class AppComponent {
  @Provides
  protected fun provideTheProvider(): suspend () -> Any = ::theProvider
}

I’m not sure if this is intended behaviour or not, but if it is then it might be worth documenting.

[evant]

Added a note in the docs.

[evant]

Note: this isn’t the first issue I’ve run into with implicit @Provides return types. I think I’m going to add a recommendation that you always explicitly declare the @Provides return type. It seems like often-times it’s not the type you expect it to be.