"Any/Is" | ts-toolbelt

Index

Type aliases

Is

Is<A, A1, match>: { 'default': Extends<A, A1>; 'implements->': Implements<A, A1>; 'extends->': Extends<A, A1>; '<-implements': Implements<A1, A>; '<-extends': Extends<A1, A>; 'equals': Equals<A1, A>; }[match]

Check whether A is similar to A1 or not. In other words, it is a compact type that bundles Equals, Extends and Implements comparison types.

Type parameters

A: any

to be compared
A1: any

to compare to
match: Match

to change precision (?='default')

returns

Boolean

example

import {A} from 'ts-toolbelt'

type test0 = A.Is<'a', 'a' | 'b', 'extends->'> // True
type test1 = A.Is<'a' | 'b', 'a', 'extends->'> // Boolean

type test2 = A.Is<'a', 'a' | 'b', '<-extends'> // Boolean
type test3 = A.Is<'a' | 'b', 'a', '<-extends'> // True

type test4 = A.Is<'a', 'a' | 'b', 'implements->'> // True
type test5 = A.Is<'a' | 'b', 'a', 'implements->'> // False

type test6 = A.Is<'a', 'a' | 'b', '<-implements'> // False
type test7 = A.Is<'a' | 'b', 'a', '<-implements'> // True

type test8 = A.Is<'a', 'a' | 'b', 'equals'>      // False
type test9 = A.Is<'b' |'a', 'a' | 'b', 'equals'> // True