Fix #9067: avoid instantiate child parameters to Wildcard if possible #9071
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…sible In tests/patmat/i9067.scala, for Foo[X1, X2] <: Base[Any, Any], X1 and X2 can both be `Any` instead of `Wildcard`. Inferring `Wildcard` will lead to the signature of `Foo.unapply` be inferred as `Nothing => Nothing`, which causes the checker to issue a false unexhaustive warning.
smarter
reviewed
May 29, 2020
smarter
approved these changes
Jun 1, 2020
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Fix #9067: avoid instantiate child parameters to Wildcard if possible
In tests/patmat/i9067.scala, for
Foo[X1, X2] <: Base[Any, Any],X1andX2can both beAnyinstead ofWildcard.Inferring
Wildcardwill lead to the signature ofFoo.unapplybe inferred as
Nothing => Nothing, which causes the checkerto issue a false unexhaustive warning.