std::option::NoneError - Rust
Description: API documentation for the Rust `NoneError` struct in crate `std`.
Keywords: rust, rustlang, rust-lang, NoneError

# [−][src]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 Clone for NoneError`[src]

#### `fn clone(&self) -> NoneError`[src]

Returns a copy of the value. Read more

#### `fn clone_from(&mut self, source: &Self)`1.0.0[src]

Performs copy-assignment from `source`. Read more

### `impl Copy for NoneError`[src]

### `impl Debug for NoneError`[src]

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

Formats the value using the given formatter. Read more

### `impl Eq for NoneError`[src]

### `impl Hash for NoneError`[src]

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

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

#### `fn hash_slice<H>(data: &[Self], state: &mut H) where
H: Hasher,` 1.3.0[src]

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

### `impl Ord for NoneError`[src]

#### `fn cmp(&self, other: &NoneError) -> Ordering`[src]

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

#### `#[must_use] fn max(self, other: Self) -> Self`1.21.0[src]

Compares and returns the maximum of two values. Read more

#### `#[must_use] fn min(self, other: Self) -> Self`1.21.0[src]

Compares and returns the minimum of two values. Read more

#### `#[must_use] fn clamp(self, min: Self, max: Self) -> Self`[src]

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

Restrict a value to a certain interval. Read more

### `impl PartialEq<NoneError> for NoneError`[src]

#### `fn eq(&self, other: &NoneError) -> bool`[src]

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

#### `#[must_use] fn ne(&self, other: &Rhs) -> bool`1.0.0[src]

This method tests for `!=`.

### `impl PartialOrd<NoneError> for NoneError`[src]

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

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

#### `#[must_use] fn lt(&self, other: &Rhs) -> bool`1.0.0[src]

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

#### `#[must_use] fn le(&self, other: &Rhs) -> bool`1.0.0[src]

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

#### `#[must_use] fn gt(&self, other: &Rhs) -> bool`1.0.0[src]

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

#### `#[must_use] fn ge(&self, other: &Rhs) -> bool`1.0.0[src]

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

### `impl StructuralEq for NoneError`[src]

### `impl StructuralPartialEq for NoneError`[src]

## Auto Trait Implementations

### `impl RefUnwindSafe for NoneError`

### `impl Send for NoneError`

### `impl Sync for NoneError`

### `impl Unpin for NoneError`

### `impl UnwindSafe for NoneError`

## Blanket Implementations

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `fn type_id(&self) -> TypeId`[src]

Gets the `TypeId` of `self`. Read more

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

#### `fn borrow(&self) -> &T`[src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

#### `fn borrow_mut(&mut self) -> &mut T`[src]

Mutably borrows from an owned value. Read more

### `impl<T> From<T> for T`[src]

#### `fn from(t: T) -> T`[src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `fn into(self) -> U`[src]

Performs the conversion.

### `impl<T> ToOwned for T where
T: Clone,` [src]

#### `type Owned = T`

The resulting type after obtaining ownership.

#### `fn to_owned(&self) -> T`[src]

Creates owned data from borrowed data, usually by cloning. Read more

#### `fn clone_into(&self, target: &mut T)`[src]

🔬 This is a nightly-only experimental API. (`toowned_clone_into` #41263)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>`[src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

#### `type Error = <U as TryFrom<T>>::Error`

The type returned in the event of a conversion error.

#### `fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>`[src]

Performs the conversion.