Vue.js: How to type computed in Vue 3 with TypeScript?

1import { ref, computed } from "vue"
2
3const count = ref(0)
4
5// Basic computed
6const doubled = computed<number>(() => count.value * 2)
7
8// Complex computed
9interface User {
10    id: number
11    name: string
12    age: number
13}
14
15const users = ref<User[]>([])
16
17const adults = computed<User[]>(() =>
18    users.value.filter(user => user.age >= 18)
19)
20
21const totalCount = computed(() => users.value.length)

1const fullName = computed<{
2    get: () => string
3    set: (value: string) => void
4}>({
5    get: () => `${firstName.value} ${lastName.value}`,
6    set: (value) => {
7        [firstName.value, lastName.value] = value.split(" ")
8    }
9})