[docs] Added note about negative narrowing for custom type guards #13964
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erictraut
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Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
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This is a documentation only fix, to try to help clarify the issue that I and others are tripping up over in #13957 and the linked discussions.
I think it is particularly necessary because all of the examples in the current docs would be valid examples for the proposed
StrictTypeGuardi.e. they returnFalseonly when the value doesn't match the type specified in theTypeGuard. That's one of the reasons why it's very easy to assume different semantics.