Remove false unchecked warnings on refined types #14703
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odersky
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Mar 20, 2022
dwijnand
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Motivation: Driven by the warnings that came out of studying a fix for #11834 (which we might resolve by making the situation impossible), I have a refactor of our typed/untyped trees which uses type members instead of type parameters (i.e. refined types instead of applied types). But doing a type test, via isInstanceOf or via pattern matching syntax, on a refined type (also) can produce spurious, i.e false positive, unchecked warnings. So with this fix I get rid of the fatal warnings in boostrapping the compiler with my Trees refactor.