Function should be assignable to (...args: any[]) => any

Obviously all functions have type Function. And likewise all functions can be given the type

type AnyFunc = (...args: any[]) => any;

AFAIK, there is nothing one can do with something of type Function that cannot be done with something of type AnyFunc and vice versa. However they are not equivalently assignable:

(f: AnyFunc): Function => f;
(f: Function): AnyFunc => f;
//                        ^
// Type 'Function' is not assignable to type 'AnyFunc'.
//   Type 'Function' provides no match for the signature '(...args: any[]): any'.

If I edit lib.d.ts to add a callable signature to Function:

interface Function {
  (...argArray: any[]): any;
  //...
}

it seems to "fix" this issue; is there any reason not to make this change for real?

首先检查 lib.d.ts 中的 Function 声明以及 issue 中展示的可赋值行为。调查 Function 和可调用签名的现有测试，然后评估添加该签名是否会保留类型系统的预期行为。当已针对演示的案例覆盖并处理所提议的可赋值性，且所有兼容性问题都已解决时，即视为完成。