#17497 - Invalid RA diagnostic error: expected 2 arguments, found 1 #17504
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…xpected 2 arguments, found 1 The issue occurs because in some configurations of traits where one of them has Deref as a supertrait, RA's type inference algorithm fails to fully resolve a trait's self type, and instead uses a TyKind::BoundVar. This then erroneously matches with types that do not implement the trait. In other words, unconnected types appear to inherit the trait's methods. The fix is to insert an optional heuristic that tells the method-lookup algorithm to continue looking for other possibly better matches, in the case where the initial match is affected by the above situation. It may find a better match, or fall back to returning the initial match. Includes a unit test that only passes after applying the fixes in this commit.
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Fix for #17497
The issue occurs because in some configurations of traits where one of them has
Derefas a supertrait, RA's type inference algorithm fails to fully resolve a trait's self type, and instead uses aTyKind::BoundVar. This then erroneously matches with types that do not implement the trait. In other words, unconnected types appear to inherit the trait's methods.The fix is to insert an optional heuristic that tells the method-lookup algorithm to continue looking for other possibly better matches, in the case where the initial match is affected by the above situation. It may find a better match, or else will fall back to returning the initial match.
Includes a unit test that only passes after applying the fixes in this commit.