How to create branded, opaque, unique, single types?

[millsp]

🤔 Question

Describe your question

Type branding is made possible by intersecting a type with a object type that has a non-existent property hidden behind a symbol type.

import {A} from 'ts-toolbelt'

type EUR = A.Type<number, 'eur'>
type USD = A.Type<number, 'usd'>

let eurWallet = 10 as EUR
let usdWallet = 15 as USD

eurWallet = usdWallet // error

Search tags, topics

nominal typing, branded types, opaque types, unique types