core::ops::Try - Rust
Description: API documentation for the Rust `Try` trait in crate `core`.
Keywords: rust, rustlang, rust-lang, Try

# [−][src]Trait core::ops::Try

    #[lang = "try"]pub trait Try {
        type Ok;
        type Error;
    #[lang = "into_result"]    fn into_result(self) -> Result<Self::Ok, Self::Error>;
    #[lang = "from_error"]    fn from_error(v: Self::Error) -> Self;
    #[lang = "from_ok"]    fn from_ok(v: Self::Ok) -> Self;
    }

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

A trait for customizing the behavior of the `?` operator.

A type implementing `Try` is one that has a canonical way to view it in terms of a success/failure dichotomy. This trait allows both extracting those success or failure values from an existing instance and creating a new instance from a success or failure value.

## Associated Types

### `type Ok`[src]

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

The type of this value when viewed as successful.

### `type Error`[src]

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

The type of this value when viewed as failed.

Loading content...

## Required methods

### `#[lang = "into_result"]fn into_result(self) -> Result<Self::Ok, Self::Error>`[src]

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

Applies the "?" operator. A return of `Ok(t)` means that the execution should continue normally, and the result of `?` is the value `t`. A return of `Err(e)` means that execution should branch to the innermost enclosing `catch`, or return from the function.

If an `Err(e)` result is returned, the value `e` will be "wrapped" in the return type of the enclosing scope (which must itself implement `Try`). Specifically, the value `X::from_error(From::from(e))` is returned, where `X` is the return type of the enclosing function.

### `#[lang = "from_error"]fn from_error(v: Self::Error) -> Self`[src]

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

Wrap an error value to construct the composite result. For example, `Result::Err(x)` and `Result::from_error(x)` are equivalent.

### `#[lang = "from_ok"]fn from_ok(v: Self::Ok) -> Self`[src]

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

Wrap an OK value to construct the composite result. For example, `Result::Ok(x)` and `Result::from_ok(x)` are equivalent.

Loading content...

## Implementors

### `impl<B, C> Try for ControlFlow<B, C>`[src]

#### `type Ok = C`

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

#### `type Error = B`

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

#### `fn into_result(self) -> Result<Self::Ok, Self::Error>`[src]

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

#### `fn from_error(v: Self::Error) -> Self`[src]

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

#### `fn from_ok(v: Self::Ok) -> Self`[src]

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

### `impl<T> Try for Option<T>`[src]

#### `type Ok = T`

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

#### `type Error = NoneError`

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

#### `fn into_result(self) -> Result<T, NoneError>`[src]

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

#### `fn from_ok(v: T) -> Self`[src]

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

#### `fn from_error(_: NoneError) -> Self`[src]

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

### `impl<T, E> Try for Result<T, E>`[src]

#### `type Ok = T`

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

#### `type Error = E`

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

#### `fn into_result(self) -> Self`[src]

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

#### `fn from_ok(v: T) -> Self`[src]

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

#### `fn from_error(v: E) -> Self`[src]

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

### `impl<T, E> Try for Poll<Option<Result<T, E>>>`[src]

#### `type Ok = Poll<Option<T>>`

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

#### `type Error = E`

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

#### `fn into_result(self) -> Result<Self::Ok, Self::Error>`[src]

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

#### `fn from_error(e: Self::Error) -> Self`[src]

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

#### `fn from_ok(x: Self::Ok) -> Self`[src]

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

### `impl<T, E> Try for Poll<Result<T, E>>`[src]

#### `type Ok = Poll<T>`

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

#### `type Error = E`

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

#### `fn into_result(self) -> Result<Self::Ok, Self::Error>`[src]

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

#### `fn from_error(e: Self::Error) -> Self`[src]

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

#### `fn from_ok(x: Self::Ok) -> Self`[src]

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