`isUndefined`, `isDefined` and `complement` typeguards

isDefined.ts

function complement<A, T extends A>(predicate: (arg: A) => arg is T): (arg: A) => arg is Exclude<A, T>;
function complement<A extends any[]>(predicate: (...args: A) => boolean) {
    return (...args: A) => !predicate(...args);
}

function isUndefined<A>(anything: A | undefined): anything is undefined;
function isUndefined(anything: any): anything is undefined {
    return anything === undefined
};

const isDefined = complement(isUndefined);

const qqq = [
    124,
    false ? 11 : undefined,
];

const qq = qqq.filter(isDefined);