BFE.dev solution for TypeScript puzzle
6. implement Omit<T, K>

author by @jichen257

Note that K extends keyof any, which means that K binds to string | number | symbol, i.e. to all desirable types of keys in the object

// solution 1
type MyOmit<T, K extends keyof any> = {
  [P in keyof T as P extends K ? never : P]: T[P]
}

Of course, where P in keyof T as P extends K ? never : P can also be abbreviated to P in Exclude<keyof T, K>, which both mean "returns P by removing from T the union members that are assignable to K.", and the usage of Exclude is not repeated here (there is a corresponding topic later)

// solution 2
type MyOmit<T, K extends keyof any> = {
  [P in Exclude<keyof T, K>]: T[P]
}