declare namespace NSFoo1 {
  export function foo(s: string): void;
  export function foo(n: number): void;
  export function bar(): void;
  export function foo(sn: string | number): void;
}

type TypeFoo1 = {
  foo(s: string): void;
  foo(n: number): void;
  bar(): void;
  foo(sn: string | number): void;
};

interface IFoo1 {
  foo(s: string): void;
  foo(n: number): void;
  bar(): void;
  foo(sn: string | number): void;
}