# Enum std::ops::ControlFlow[−][src]

    pub enum ControlFlow<B, C = ()> {
        Continue(C),
        Break(B),
    }

🔬 This is a nightly-only experimental API. (`control_flow_enum` #75744)

new API

Used to make try_fold closures more like normal loops

## Variants

`Continue(C)`
🔬 This is a nightly-only experimental API. (`control_flow_enum` #75744)

new API

Continue in the loop, using the given value for the next iteration

`Break(B)`
🔬 This is a nightly-only experimental API. (`control_flow_enum` #75744)

new API

Exit the loop, yielding the given value

## Implementations

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

#### `pub fn is_break(&self) -> bool`[src]

🔬 This is a nightly-only experimental API. (`control_flow_enum` #75744)

new API

Returns `true` if this is a `Break` variant.

#### `pub fn is_continue(&self) -> bool`[src]

🔬 This is a nightly-only experimental API. (`control_flow_enum` #75744)

new API

Returns `true` if this is a `Continue` variant.

#### `pub fn break_value(self) -> Option<B>`[src]

🔬 This is a nightly-only experimental API. (`control_flow_enum` #75744)

new API

Converts the `ControlFlow` into an `Option` which is `Some` if the `ControlFlow` was `Break` and `None` otherwise.

#### `pub fn map_break<T, F>(self, f: F) -> ControlFlow<T, C> where
F: FnOnce(B) -> T,` [src]

🔬 This is a nightly-only experimental API. (`control_flow_enum` #75744)

new API

Maps `ControlFlow<B, C>` to `ControlFlow<T, C>` by applying a function to the break value in case it exists.

### `impl<R> ControlFlow<R, <R as Try>::Ok> where
R: Try,` [src]

#### `pub fn from_try(r: R) -> ControlFlow<R, <R as Try>::Ok>`[src]

🔬 This is a nightly-only experimental API. (`control_flow_enum` #75744)

new API

Create a `ControlFlow` from any type implementing `Try`.

#### `pub fn into_try(self) -> R`[src]

🔬 This is a nightly-only experimental API. (`control_flow_enum` #75744)

new API

Convert a `ControlFlow` into any type implementing `Try`;

### `impl<B> ControlFlow<B, ()>`[src]

#### `pub const CONTINUE: ControlFlow<B, ()>`[src]

🔬 This is a nightly-only experimental API. (`control_flow_enum` #75744)

new API

It's frequently the case that there's no value needed with `Continue`, so this provides a way to avoid typing `(())`, if you prefer it.

# Examples

    #![feature(control_flow_enum)]
    use std::ops::ControlFlow;

    let mut partial_sum = 0;
    let last_used = (1..10).chain(20..25).try_for_each(|x| {
        partial_sum += x;
        if partial_sum > 100 { ControlFlow::Break(x) }
        else { ControlFlow::CONTINUE }
    });
    assert_eq!(last_used.break_value(), Some(22));

Run

### `impl<C> ControlFlow<(), C>`[src]

#### `pub const BREAK: ControlFlow<(), C>`[src]

🔬 This is a nightly-only experimental API. (`control_flow_enum` #75744)

new API

APIs like `try_for_each` don't need values with `Break`, so this provides a way to avoid typing `(())`, if you prefer it.

# Examples

    #![feature(control_flow_enum)]
    use std::ops::ControlFlow;

    let mut partial_sum = 0;
    (1..10).chain(20..25).try_for_each(|x| {
        if partial_sum > 100 { ControlFlow::BREAK }
        else { partial_sum += x; ControlFlow::CONTINUE }
    });
    assert_eq!(partial_sum, 108);

Run

## Trait Implementations

### `impl<B, C> Clone for ControlFlow<B, C> where
C: Clone,
B: Clone,` [src]

#### `pub fn clone(&self) -> ControlFlow<B, C>`[src]

Returns a copy of the value. Read more

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

Performs copy-assignment from `source`. Read more

### `impl<B, C> Copy for ControlFlow<B, C> where
C: Copy,
B: Copy,` [src]

### `impl<B, C> Debug for ControlFlow<B, C> where
C: Debug,
B: Debug,` [src]

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

Formats the value using the given formatter. Read more

### `impl<B, C> PartialEq<ControlFlow<B, C>> for ControlFlow<B, C> where
C: PartialEq<C>,
B: PartialEq<B>,` [src]

#### `pub fn eq(&self, other: &ControlFlow<B, C>) -> bool`[src]

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

#### `pub fn ne(&self, other: &ControlFlow<B, C>) -> bool`[src]

This method tests for `!=`.

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

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

#### `type Ok = C`

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

The type of this value when viewed as successful.

#### `type Error = B`

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

The type of this value when viewed as failed.

#### `pub fn into_result(
self
) -> Result<<ControlFlow<B, C> as Try>::Ok, <ControlFlow<B, C> as Try>::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. Read more

#### `pub fn from_error(v: <ControlFlow<B, C> as Try>::Error) -> ControlFlow<B, C>`[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. Read more

#### `pub fn from_ok(v: <ControlFlow<B, C> as Try>::Ok) -> ControlFlow<B, C>`[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. Read more

## Auto Trait Implementations

### `impl<B, C> RefUnwindSafe for ControlFlow<B, C> where
B: RefUnwindSafe,
C: RefUnwindSafe,` [src]

### `impl<B, C> Send for ControlFlow<B, C> where
B: Send,
C: Send,` [src]

### `impl<B, C> Sync for ControlFlow<B, C> where
B: Sync,
C: Sync,` [src]

### `impl<B, C> Unpin for ControlFlow<B, C> where
B: Unpin,
C: Unpin,` [src]

### `impl<B, C> UnwindSafe for ControlFlow<B, C> where
B: UnwindSafe,
C: UnwindSafe,` [src]

## Blanket Implementations

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

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

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

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

#### `pub fn borrow(&self) -> &Tⓘ

### Notable traits for &'_ mut F

`impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W`
`[src]

Immutably borrows from an owned value. Read more

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

#### `pub fn borrow_mut(&mut self) -> &mut Tⓘ

### Notable traits for &'_ mut F

`impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W`
`[src]

Mutably borrows from an owned value. Read more

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

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

Performs the conversion.

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

#### `pub 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.

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

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

#### `pub 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.

#### `pub 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.

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

Performs the conversion.