allow meaningful wildcard type arguments to Event and Instance#982
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Ladicek wants to merge 1 commit into
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allow meaningful wildcard type arguments to Event and Instance#982Ladicek wants to merge 1 commit into
Ladicek wants to merge 1 commit into
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This was referenced Jun 1, 2026
The type parameter of `Event` is naturally contravariant, so injecting `Event<? super Whatever>` is meaningful (although it's exactly as useful as plain `Event<Whatever>`). Similarly, the type parameter of `Instance` is naturally covariant, so injecting `Instance<? extends Whatever>` is meaningful. This commit tightens the specification rules for wildcard type arguments to `Event` and `Instance` so that the meaningful cases as described above are _not_ definition errors and still work. Also the definition of specified type of an injected `Event` and required type of an injected `Instance` are tightened such that if an allowed wildcard is specified, its bound is used instead.
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The type parameter of
Eventis naturally contravariant, so injectingEvent<? super Whatever>is meaningful (although it's exactly as useful as plainEvent<Whatever>).Similarly, the type parameter of
Instanceis naturally covariant, so injectingInstance<? extends Whatever>is meaningful.This commit tightens the specification rules for wildcard type arguments to
EventandInstanceso that the meaningful cases as described above are not definition errors and still work.