Trait frame_support::traits::DefensiveOption

pub trait DefensiveOption<T> {
    // Required methods
    fn defensive_map_or_else<U, D: FnOnce() -> U, F: FnOnce(T) -> U>(
        self,
        default: D,
        f: F
    ) -> U;
    fn defensive_ok_or_else<E: Debug, F: FnOnce() -> E>(
        self,
        err: F
    ) -> Result<T, E>;
    fn defensive_ok_or<E: Debug>(self, err: E) -> Result<T, E>;
    fn defensive_map<U, F: FnOnce(T) -> U>(self, f: F) -> Option<U>;
}

Subset of methods similar to Defensive that can only work for a Option.

Required Methods

fn defensive_map_or_else<U, D: FnOnce() -> U, F: FnOnce(T) -> U>( self, default: D, f: F ) -> U

Potentially map and unpack the value to something else (U), or call the default callback if None, which should never happen.

fn defensive_ok_or_else<E: Debug, F: FnOnce() -> E>( self, err: F ) -> Result<T, E>

Defensively transform this option to a result, mapping None to the return value of an error closure.

fn defensive_ok_or<E: Debug>(self, err: E) -> Result<T, E>

Defensively transform this option to a result, mapping None to a default value.

fn defensive_map<U, F: FnOnce(T) -> U>(self, f: F) -> Option<U>

Exactly the same as map, but it prints the appropriate warnings if the value being mapped is None.

Implementations on Foreign Types

impl<T> DefensiveOption<T> for Option<T>

fn defensive_map_or_else<U, D: FnOnce() -> U, F: FnOnce(T) -> U>( self, default: D, f: F ) -> U

fn defensive_ok_or_else<E: Debug, F: FnOnce() -> E>( self, err: F ) -> Result<T, E>

fn defensive_ok_or<E: Debug>(self, err: E) -> Result<T, E>

fn defensive_map<U, F: FnOnce(T) -> U>(self, f: F) -> Option<U>

Implementors