gistfile1.txt

type Input <T> = string | number | T

const i: Input<boolean> = false

const x: Input<number[]> = [1, 2, 3]

interface Guest {
  name: string
  email: string
  age: number
}

type AgelessGuest = Omit<Guest, 'age' | 'name'>

interface Output <T extends keyof Guest> {
  date: number
  result: T
}

type DatelessOutput = Omit<Output<'email'>, 'date'>

const output1: Output<'name'> = {
  date: 123,
  result: 'name' 
}

const output2: Output<'age'> = {
  date: 345,
  result: 'age' 
}

class Container <T> {
  items: T[]

  constructor () {
    this.items = []
  }
}

const stringContainer = new Container<string>
stringContainer.items.push('hello')

function labelItem <T extends object> (item: T) {
  return {
    label: 'ready',
    item
  }
}
type LabelResult = ReturnType<typeof labelItem>

const labeled = labelItem({ abc: 1 })