Reimplementing function type helpers

helpers.ts

function add(a: number, b: number): number {
  return a + b;
}

type MyParameters<TFunc extends (...args: any[]) => unknown> = TFunc extends (
  ...args: infer TArgs
) => unknown
  ? TArgs
  : unknown;

type Args = MyParameters<typeof add>;
//   ^?

type MyResultType<TFunc extends (...args: any[]) => unknown> = TFunc extends (
  ...args: any
) => infer TResult
  ? TResult
  : unknown;

type Result = MyResultType<typeof add>;

type MyThisParameterType<TFunc extends (this: any, ...args: any[]) => unknown> =
  TFunc extends (this: infer TThis, ...args: any) => any ? TThis : unknown;

type This = MyThisParameterType<typeof add>;