isNone

function isNone<T>(option): option is Readonly<{ __option: 'None' }>;

Checks whether the given Option contains no value.

This function acts as a type guard, ensuring the value is a None.

Type Parameters

Parameters

Returns

option is Readonly<{ __option: "None" }>

true if the option is a None, false otherwise.

Example

Checking for None values.

isNone(some(42)); // false
isNone(none());   // true

See

• Option
• None