Typescript: Should 'Partial<T>' and Readonly<T> should have their type parameters constrained to 'object'?

[DanielRosenwasser]

Given #14224, I think that Partial should be defined as follows:

type Partial<T extends object> = {
    [K in keyof T]?: T[K]
}

Readonly could be defined similarly.

I don't necessarily know if Pick should be defined that way. Part of me thinks that this Pick has a different intent.

[mhegazy]

mapped type in general handle primitives differently. but i agree that these types should not be used on a primitive.

the problem now is in any generic function every-time you write Partial<T> you have to constrain T extends object.

[Knagis]

I have recently used Partial<> like this:

type Foo<T> = {
  [K in keyof T]: Partial<T[K]>
}

Wouldn't the constraint prohibit this? Of course, I could create my own Partial<> definition that skips the constraint.

[RyanCavanaugh]

Too annoying to force authors to constrain their own type parameters to object if we did this