BoundType

This annotation is used with ContributesBinding, ContributesIntoSet, and ContributesIntoMap to define a bound type. This is analogous to the bound type of a Binds-annotated declaration.

The generic type T should be the bound type, which the compiler plugin will read at compile-time.

This is only necessary when the bound type is not implicit on the class itself (i.e. it has multiple declared supertypes or the desired bound type is not the single explicitly declared supertype).

@ContributesBinding(AppScope::class, boundType = BoundType<Base>())
class Impl : Base, AnotherBase

For contributions with Qualifiers, the T type argument can be annotated with the qualifier annotation. If none is defined, the compiler will fall back to the qualifier annotation on the class, if any.

// Uses the qualifier on `boundType`
@ContributesBinding(AppScope::class, boundType = BoundType<@Named("qualified") Base>())
class Impl : Base, AnotherBase

// Falls back to the class
@Named("qualified")
@ContributesBinding(AppScope::class, boundType = BoundType<Base>())
class Impl : Base, AnotherBase

For ContributesIntoMap bindings, the T type argument should also be annotated with a MapKey. If none is defined on T, there must be one on the annotated class to use.

@ContributesIntoMap(AppScope::class, boundType = BoundType<@ClassKey(Impl::class) Base>())
class Impl : Base, AnotherBase