TypeScript/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/typeParameterAssignability3.ts
2014-07-12 17:30:19 -07:00

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512 B
TypeScript

// type parameters are not assignable to one another unless directly or indirectly constrained to one another
class Foo { foo: string; }
function foo<T extends Foo, U extends Foo>(t: T, u: U) {
var a: T;
var b: U;
t = a; // ok
a = t; // ok
b = u; // ok
u = b; // ok
t = u; // error
u = t; // error
}
class C<T extends Foo, U extends Foo> {
t: T;
u: U;
r = () => {
this.t = this.u; // error
this.u = this.t; // error
}
}