[ts]implements类的重载实现

implements类的函数重载需要在类中声明与所实现接口一致的函数重载声明【ts 4.1.3】

interface Test {
    t1(p: string): number;
    t1(p: number): string;
}

class TestClass implements Test {
    t1(p: string): number;
    t1(p: number): string;
    t1(p: string | number) {
        return typeof p === 'string' ? Number(p) : String(p);
    }
}