Add signatures that enable TypeScript type guards #4
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This enables you to write `.find((e): e is Derived => e instanceof Derived)` and TypeScript will infer the type of the expression to be `Derived` instead of the type of the collection. (Similarly for the other methods.)
Owner
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Why would you not simply declare the collection to be |
Contributor
Author
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It contains object of multiple subtypes, but you happen to know that the one you're trying to find has a specific subtype. |
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This enables you to write
.find((e): e is Derived => e instanceof Derived)and TypeScript will infer the type of the expression to beDerivedinstead of the type of the collection. (Similarly for the other methods.)