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

# Struct core::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

###

`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 PartialEq 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 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 Eq for NoneError`

[src]

###

`impl Ord for NoneError`

[src]

####

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

[src]

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

####

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

1.21.0
[src]

Compares and returns the maximum of two values. Read more

####

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

1.21.0
[src]

Compares and returns the minimum of two values. Read more

###

`impl Debug for NoneError`

[src]

####

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

[src]

Formats the value using the given formatter. Read more

###

`impl Hash for NoneError`

[src]

####

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

[src]

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

####

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

1.3.0
[src]

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

## Auto Trait Implementations

###

`impl Send for NoneError`

###

`impl Sync for NoneError`

# Help

## Keyboard Shortcuts

`?`
  Show this help dialog
`S`
  Focus the search field
`↑`
  Move up in search results
`↓`
  Move down in search results
`↹`
  Switch tab
`⏎`
  Go to active search result
`+`
  Expand all sections
`-`
  Collapse all sections

## Search Tricks

Prefix searches with a type followed by a colon (e.g. `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g. `vec -> usize` or `* -> vec`)

Search multiple things at once by splitting your query with comma (e.g. `str,u8` or `String,struct:Vec,test`)