20 lines
789 B
TypeScript
20 lines
789 B
TypeScript
//// [contextualSignatureInstatiationContravariance.ts]
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interface Animal { x }
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interface Giraffe extends Animal { y }
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interface Elephant extends Animal { y2 }
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var f2: <T extends Animal>(x: T, y: T) => void;
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var g2: (g: Giraffe, e: Elephant) => void;
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g2 = f2; // valid because both Giraffe and Elephant satisfy the constraint. T is Animal
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var h2: (g1: Giraffe, g2: Giraffe) => void;
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h2 = f2; // valid because Giraffe satisfies the constraint. It is safe in the traditional contravariant fashion.
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//// [contextualSignatureInstatiationContravariance.js]
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var f2;
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var g2;
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g2 = f2; // valid because both Giraffe and Elephant satisfy the constraint. T is Animal
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var h2;
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h2 = f2; // valid because Giraffe satisfies the constraint. It is safe in the traditional contravariant fashion.
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