Type Alias Narrow<T>

Narrow: T extends string
? string extends T ? T : T
: T extends number ? number extends T ? T : T : T

Narrow a type without widening literals.

Type Parameters

T
Type to narrow

Remarks

Preserves literal types while leaving their corresponding base types unchanged. Primarily useful as a semantic marker in public APIs.

Example

type A = Narrow< 'hello' >; // 'hello'
type B = Narrow< string >;  // string