Type Alias IsLiteral<T>

IsLiteral: IsAny<T> extends true
    ? false
    : string extends T
        ? false
        : number extends T ? false : boolean extends T ? false : true

Test whether a type is a literal type.

Type Parameters

T
Type to test

Remarks

Distinguishes string, number, and boolean literals from their corresponding primitive base types. The any type always resolves to false to avoid false positives.

Example

type A = IsLiteral< 'hello' >;  // true
type B = IsLiteral< 42 >;       // true
type C = IsLiteral< true >;     // true
type D = IsLiteral< string >;   // false

Type Alias IsLiteral<T>

Type Parameters

Remarks

Example

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