Type Alias IsTuple<T, $O>

IsTuple: $Special<
    T,
    $MergeOptions<
        $O,
        { $else: IsTuple.$<T, $O>; $then: $ResolveBranch<$O, [$Else]> },
    >,
>

🎭 predicate

Validate that T is a tuple, excluding array.

type R = IsTuple<[]>       // true

type R = IsTuple<number[]> // false
type R = IsTuple<string>   // false
type R = IsTuple<never>    // false
type R = IsTuple<unknown>  // false

🔢 customize

Filter to ensure T is a tuple, otherwise returns never.

Type Parameters

T
$O extends IsTuple.$Options = {}

Example

type R = IsTuple<[], { selection: 'filter' }> // []
type R = IsTuple<[1], { selection: 'filter' }> // [1]

type R = IsTuple<never, { selection: 'filter' }> // never
type R = IsTuple<unknown, { selection: 'filter' }> // never
type R = IsTuple<[] | boolean, { selection: 'filter' }> // []

🔢 customize:

Disable distribution of union types.

type R = IsTuple<[1] | 1> // boolean
type R = IsTuple<[] | 1, { distributive: false }> // false

🔢 customize

Use unique branch identifiers to allow precise processing of the result.

Example

type R = IsTuple<[], IsTuple.$Branch> // $Then
type R = IsTuple<string, IsTuple.$Branch> // $Else

Type Alias IsTuple<T, $O>

Type Parameters

Example

Example

Settings