Type alias IsNotFalse<T, $O>

🎭 predicate

Validate if T is not false.

Example

type R = IsNotFalse<boolean> // boolean
type R = IsNotFalse<true> // true
type R = IsNotFalse<false> // false

type R = IsNotFalse<number> // true
type R = IsNotFalse<unknown> // true
type R = IsNotFalse<string | boolean> // boolean
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🔢 customize

Filter to ensure T is not false, otherwise returns never.

Example

type R = IsNotFalse<boolean, { selection: 'filter' }> // true
type R = IsNotFalse<true, { selection: 'filter' }> // true
type R = IsNotFalse<false, { selection: 'filter' }> // never

type R = IsNotFalse<number, { selection: 'filter' }> // number
type R = IsNotFalse<never, { selection: 'filter' }> // never
type R = IsNotFalse<unknown, { selection: 'filter' }> // unknown
type R = IsNotFalse<string | boolean, { selection: 'filter' }> // string | true
type R = IsNotFalse<string | false, { selection: 'filter' }> // string
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🔢 customize:

Disable distribution of union types.

type R = IsNotFalse<false | 1> // boolean
type R = IsNotFalse<boolean | 1> // boolean
type R = IsNotFalse<boolean | 1, { distributive: false }> // true
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🔢 customize

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

Example

type R = IsNotFalse<false, $SelectionBranch> // $Else
type R = IsNotFalse<boolean, $SelectionBranch> // $Then | $Else
type R = IsNotFalse<string, $SelectionBranch> // $Then
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