Javascript 构造函数作为对象键

我试图构建类型和回调的映射，所以我从如下 struct 开始:

type Instantiable<T = unknown> = new (...args: any[]) => T;
type SingleParamFn<TInput = unknown, TOuput = unknown> = (arg: TInput) => TOuput;

type TypesRecord<T> = { type: Instantiable<T>, callback: SingleParamFn<T> };
type TypesMap = TypesRecord[];   // This is the structure

例如:

const myMap: TypesMap = [{ type: Date, callback: (value) => 'this is a Date' }];

这似乎像预期的那样工作，但我意识到这有点低效，因为需要循环数组以找到所需的类型.

我开始try 将这些类型作为对象键，至少在Google Chrome中是这样的:

class MyFancyObject {}
class MyOtherObject {}

const map = {
   [Date]: () => 'this is a date',
   [MyFancyObject]: () => 'this is a fancy object',
   [MyOtherObject]: () => 'this is another object'
};

console.log(map[Date]());           // 'this is a date'
console.log(map[MyFancyObject]());  // 'this is a fancy object'
console.log(map[MyOtherObject]());  // 'this is another object'

const obj = new MyFancyObject();
console.log(map[obj.constructor]());           // 'this is a fancy object'
console.log(map[(new Date()).constructor]());  // 'this is a date'

我一直在判断一些文档，似乎一个对象的键只能是string or a Symbol，所以我判断了符号的组成，它似乎有点奇怪，因为它被定义为built-in object whose constructor returns a symbol primitive that's guaranteed to be unique，而对象的构造函数(据我所知)是唯一的.

考虑到所有这些，使用构造函数作为对象键是一种可靠的方法吗？如果是，如何定义此类对象的typescript类型？如果不是，是否还有其他选项(如Map对象)？