Struct std::option::NoneError

pub struct NoneError;

🔬 This is a nightly-only experimental API. (try_trait #42327)

The error type that results from applying the try operator (?) to a None value. If you wish to allow x? (where x is an Option<T>) to be converted into your error type, you can implement impl From<NoneError> for YourErrorType. In that case, x? within a function that returns Result<_, YourErrorType> will translate a None value into an Err result.

Trait Implementations

impl Debug for NoneError

fn fmt(&self, f: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.

impl Hash for NoneError

fn hash<__H>(&self, state: &mut __H) where
    __H: Hasher, 

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl Eq for NoneError

impl Clone for NoneError

fn clone(&self) -> NoneError

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl PartialEq<NoneError> for NoneError

fn eq(&self, other: &NoneError) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialOrd<NoneError> for NoneError

fn partial_cmp(&self, other: &NoneError) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use] fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use] fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use] fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use] fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Ord for NoneError

fn cmp(&self, other: &NoneError) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp #44095)

Restrict a value to a certain interval.

impl Copy for NoneError