typescript将字符串数组转换为类型

function asLiterals<T extends string>(arr: T[]): T[] { return arr; }

const s = asLiterals(['foo', 'rolo', 'zoombaz']);
// s => ('foo' | 'rolo' | 'zoombaz')[]
type v = {[K in (typeof s)[number]]: string};
// v => { foo: string, role: string, zoombaz: string }