std::option

Status: experimental

Option combinators as data-first free functions for pipelines: map, filter, unwrap_or, and_then, etc.

Items

Item	Signature	Description
and_then	fn and_then<T, U>(value: Option<T>, f: Fn(T) -> Option<U>) -> Option<U>	Chains a fallible step: Some(v) -> f(v), None stays None.
unwrap	fn unwrap<T>(value: Option<T>) -> T	Returns the payload, panicking when the value is None.
expect	fn expect<T>(value: Option<T>, message: String) -> T	Returns the payload, panicking with the message when the value is None.
unwrap_or	fn unwrap_or<T>(value: Option<T>, fallback: T) -> T	Unwraps with a fallback value for None.
unwrap_or_else	fn unwrap_or_else<T>(value: Option<T>, fallback: Fn() -> T) -> T	Unwraps with a lazily computed fallback for None.
filter	fn filter<T>(value: Option<T>, predicate: Fn(T) -> bool) -> Option<T>	Keeps Some(v) only when the predicate holds.
flatten	fn flatten<T>(value: Option<Option<T>>) -> Option<T>	Collapses Option<Option> one level.
is_none	fn is_none<T>(value: Option<T>) -> bool	True for None.
is_some	fn is_some<T>(value: Option<T>) -> bool	True for Some.
ok_or	fn ok_or<T, E>(value: Option<T>, err: E) -> Result<T, E>	Converts Some to Ok, or None to Err with the provided error.
ok_or_else	fn ok_or_else<T, E>(value: Option<T>, err: Fn() -> E) -> Result<T, E>	Converts Some to Ok, or None to Err from a fallback closure.
iter	fn iter<T>(value: Option<T>) -> Vec<T>	Zero-or-one element sequence view.
map	fn map<T, U>(value: Option<T>, f: Fn(T) -> U) -> Option<U>	Transforms the Some payload, None stays None.
or	fn or<T>(value: Option<T>, fallback: Option<T>) -> Option<T>	First Some of self and the alternative.
or_else	fn or_else<T>(value: Option<T>, fallback: Fn() -> Option<T>) -> Option<T>	First Some of self and a lazily built alternative.
zip	fn zip<T, U>(value: Option<T>, other: Option<U>) -> Option<(T, U)>	Pairs two Somes into Some((a, b)).