The generics don't work with the type of a key value object

[zabirauf]

TypeScript Version: 2.4.0 / nightly (2.5.0-dev.201xxxxx)

Code

// A *self-contained* demonstration of the problem follows...
function test<T extends string | number>(a: T): {[key: T]: boolean} {
    const map: { [key: T]: boolean } = {};
    return map;
}

Expected behavior:
The type system should not complain that the key type of map should be string or number.

Actual behavior:
It gives error that the key of map should be string or number even though T is string or number

[snewell92]

Possibly related

type Key = string | number;

const dict: { [index: Key]: any } = {};

[mhegazy]

duplicate of #16760 #14934

[mhegazy]

Automatically closing this issue for housekeeping purposes. The issue labels indicate that it is unactionable at the moment or has already been addressed.