Option::is_none

pub fn is_none() -> bool

True when this is None.

Called on a Option value as value.is_none(…).

Returns#

bool

See also#

• Option
• Option::is_some: True when this is Some.
• Option::unwrap_or: The value, or fallback when None.
• Option::unwrap_or_else: The value, or the result of f when None.
• Option::map: Some(f(value)), or None.
• Option::map_or: f(value), or fallback when None.
• Option::and_then: f(value) (itself an Option), or None.
• Option::or: This option if it is Some, otherwise other.