# Struct std::option::NoneError[−][src]

    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

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`impl Debug for NoneError`

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

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Formats the value using the given formatter. Read more

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`impl Copy for NoneError`

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`impl Clone for NoneError`

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`fn clone(&self) -> NoneError`

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Returns a copy of the value. Read more

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

1.0.0
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Performs copy-assignment from `source`. Read more

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`impl PartialOrd<NoneError> for NoneError`

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

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

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

1.0.0
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This method tests less than (for `self` and `other`) and is used by the `<` operator. Read more

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

1.0.0
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This method tests less than or equal to (for `self` and `other`) and is used by the `<=` operator. Read more

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

1.0.0
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This method tests greater than (for `self` and `other`) and is used by the `>` operator. Read more

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

1.0.0
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This method tests greater than or equal to (for `self` and `other`) and is used by the `>=` operator. Read more

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`impl Ord for NoneError`

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

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This method returns an `Ordering` between `self` and `other`. Read more

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

1.21.0
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Compares and returns the maximum of two values. Read more

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

1.21.0
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Compares and returns the minimum of two values. Read more

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`impl Eq for NoneError`

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`impl PartialEq<NoneError> for NoneError`

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

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

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

1.0.0
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This method tests for `!=`.

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`impl Hash for NoneError`

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

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Feeds this value into the given [`Hasher`]. Read more

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

1.3.0
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Feeds a slice of this type into the given [`Hasher`]. Read more

## Auto Trait Implementations

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`impl Send for NoneError`

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`impl Sync for NoneError`

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