TypeScript/tests/cases/compiler/contextualSignatureInstatiationContravariance.ts
2014-07-12 17:30:19 -07:00

11 lines
441 B
TypeScript

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; // valid because both Giraffe and Elephant satisfy the constraint. T is Animal
var h2: (g1: Giraffe, g2: Giraffe) => void;
h2 = f2; // valid because Giraffe satisfies the constraint. It is safe in the traditional contravariant fashion.