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tests/cases/compiler/contextualSignatureInstatiationContravariance.ts(8,1): error TS2322: Type '<T extends Animal>(x: T, y: T) => void' is not assignable to type '(g: Giraffe, e: Elephant) => void'.
Types of parameters 'y' and 'e' are incompatible.
Property 'y' is missing in type 'Elephant' but required in type 'Giraffe'.
==== tests/cases/compiler/contextualSignatureInstatiationContravariance.ts (1 errors) ====
interface Animal { x }
interface Giraffe extends Animal { y }
interface Elephant extends Animal { y2 }
var f2: <T extends Animal>(x: T, y: T) => void;
var g2: (g: Giraffe, e: Elephant) => void;
g2 = f2; // error because Giraffe and Elephant are disjoint types
~~
!!! error TS2322: Type '<T extends Animal>(x: T, y: T) => void' is not assignable to type '(g: Giraffe, e: Elephant) => void'.
!!! error TS2322: Types of parameters 'y' and 'e' are incompatible.
!!! error TS2322: Property 'y' is missing in type 'Elephant' but required in type 'Giraffe'.
!!! related TS2728 tests/cases/compiler/contextualSignatureInstatiationContravariance.ts:2:36: 'y' is declared here.
var h2: (g1: Giraffe, g2: Giraffe) => void;
h2 = f2; // valid because Giraffe satisfies the constraint. It is safe in the traditional contravariant fashion.
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