Function isNone

isNone<O extends UnknownOptional>(optional: O): optional is NarrowToNone<O>
Checks if an Optional is None. Acts as a type guard.
Type Parameters
- O extends UnknownOptional
  The UnknownOptional type to check.
Parameters
- optional: O
  The Optional to check.
Returns optional is NarrowToNone<O>
true if the Optional is None, false otherwise.
Example
```
const optionalValue = Optional.none as Optional<number>;

if (Optional.isNone(optionalValue)) {
  // Type narrowed to None
  expectType<typeof optionalValue, None>('=');
}
```
- Defined in src/functional/optional/impl/optional-is-none.mts:23