# Struct bitflags::__core::sync::atomic::AtomicBool [−] [src]

    pub struct AtomicBool {
        // some fields omitted
    }

1.0.0

A boolean type which can be safely shared between threads.

## Methods

### `impl AtomicBool`

#### `const fn new(v: bool) -> AtomicBool`

Creates a new `AtomicBool`.

# Examples

    use std::sync::atomic::AtomicBool;

    let atomic_true  = AtomicBool::new(true);
    let atomic_false = AtomicBool::new(false);

#### `fn load(&self, order: Ordering) -> bool`

Loads a value from the bool.

`load` takes an `Ordering` argument which describes the memory ordering of this operation.

# Panics

Panics if `order` is `Release` or `AcqRel`.

# Examples

    use std::sync::atomic::{AtomicBool, Ordering};

    let some_bool = AtomicBool::new(true);

    assert_eq!(some_bool.load(Ordering::Relaxed), true);

#### `fn store(&self, val: bool, order: Ordering)`

Stores a value into the bool.

`store` takes an `Ordering` argument which describes the memory ordering of this operation.

# Examples

    use std::sync::atomic::{AtomicBool, Ordering};

    let some_bool = AtomicBool::new(true);

    some_bool.store(false, Ordering::Relaxed);
    assert_eq!(some_bool.load(Ordering::Relaxed), false);

# Panics

Panics if `order` is `Acquire` or `AcqRel`.

#### `fn swap(&self, val: bool, order: Ordering) -> bool`

Stores a value into the bool, returning the old value.

`swap` takes an `Ordering` argument which describes the memory ordering of this operation.

# Examples

    use std::sync::atomic::{AtomicBool, Ordering};

    let some_bool = AtomicBool::new(true);

    assert_eq!(some_bool.swap(false, Ordering::Relaxed), true);
    assert_eq!(some_bool.load(Ordering::Relaxed), false);

#### `fn compare_and_swap(&self, current: bool, new: bool, order: Ordering) -> bool`

Stores a value into the `bool` if the current value is the same as the `current` value.

The return value is always the previous value. If it is equal to `current`, then the value was updated.

`compare_and_swap` also takes an `Ordering` argument which describes the memory ordering of this operation.

# Examples

    use std::sync::atomic::{AtomicBool, Ordering};

    let some_bool = AtomicBool::new(true);

    assert_eq!(some_bool.compare_and_swap(true, false, Ordering::Relaxed), true);
    assert_eq!(some_bool.load(Ordering::Relaxed), false);

    assert_eq!(some_bool.compare_and_swap(true, true, Ordering::Relaxed), false);
    assert_eq!(some_bool.load(Ordering::Relaxed), false);

#### `fn compare_exchange(&self, current: bool, new: bool, success: Ordering, failure: Ordering) -> Result<bool, bool>`

Unstable (`extended_compare_and_swap`)

: recently added

Stores a value into the `bool` if the current value is the same as the `current` value.

The return value is a result indicating whether the new value was written and containing the previous value. On success this value is guaranteed to be equal to `new`.

`compare_exchange` takes two `Ordering` arguments to describe the memory ordering of this operation. The first describes the required ordering if the operation succeeds while the second describes the required ordering when the operation fails. The failure ordering can't be `Release` or `AcqRel` and must be equivalent or weaker than the success ordering.

# Examples

    use std::sync::atomic::{AtomicBool, Ordering};

    let some_bool = AtomicBool::new(true);

    assert_eq!(some_bool.compare_exchange(true,
                                          false,
                                          Ordering::Acquire,
                                          Ordering::Relaxed),
               Ok(true));
    assert_eq!(some_bool.load(Ordering::Relaxed), false);

    assert_eq!(some_bool.compare_exchange(true, true,
                                          Ordering::SeqCst,
                                          Ordering::Acquire),
               Err(false));
    assert_eq!(some_bool.load(Ordering::Relaxed), false);

#### `fn compare_exchange_weak(&self, current: bool, new: bool, success: Ordering, failure: Ordering) -> Result<bool, bool>`

Unstable (`extended_compare_and_swap`)

: recently added

Stores a value into the `bool` if the current value is the same as the `current` value.

Unlike `compare_exchange`, this function is allowed to spuriously fail even when the comparison succeeds, which can result in more efficient code on some platforms. The return value is a result indicating whether the new value was written and containing the previous value.

`compare_exchange_weak` takes two `Ordering` arguments to describe the memory ordering of this operation. The first describes the required ordering if the operation succeeds while the second describes the required ordering when the operation fails. The failure ordering can't be `Release` or `AcqRel` and must be equivalent or weaker than the success ordering.

# Examples

    use std::sync::atomic::{AtomicBool, Ordering};

    let val = AtomicBool::new(false);

    let new = true;
    let mut old = val.load(Ordering::Relaxed);
    loop {
        match val.compare_exchange_weak(old, new, Ordering::SeqCst, Ordering::Relaxed) {
            Ok(_) => break,
            Err(x) => old = x,
        }
    }

#### `fn fetch_and(&self, val: bool, order: Ordering) -> bool`

Logical "and" with a boolean value.

Performs a logical "and" operation on the current value and the argument `val`, and sets the new value to the result.

Returns the previous value.

# Examples

    use std::sync::atomic::{AtomicBool, Ordering};

    let foo = AtomicBool::new(true);
    assert_eq!(foo.fetch_and(false, Ordering::SeqCst), true);
    assert_eq!(foo.load(Ordering::SeqCst), false);

    let foo = AtomicBool::new(true);
    assert_eq!(foo.fetch_and(true, Ordering::SeqCst), true);
    assert_eq!(foo.load(Ordering::SeqCst), true);

    let foo = AtomicBool::new(false);
    assert_eq!(foo.fetch_and(false, Ordering::SeqCst), false);
    assert_eq!(foo.load(Ordering::SeqCst), false);

#### `fn fetch_nand(&self, val: bool, order: Ordering) -> bool`

Logical "nand" with a boolean value.

Performs a logical "nand" operation on the current value and the argument `val`, and sets the new value to the result.

Returns the previous value.

# Examples

    use std::sync::atomic::{AtomicBool, Ordering};

    let foo = AtomicBool::new(true);
    assert_eq!(foo.fetch_nand(false, Ordering::SeqCst), true);
    assert_eq!(foo.load(Ordering::SeqCst), true);

    let foo = AtomicBool::new(true);
    assert_eq!(foo.fetch_nand(true, Ordering::SeqCst), true);
    assert_eq!(foo.load(Ordering::SeqCst) as usize, 0);
    assert_eq!(foo.load(Ordering::SeqCst), false);

    let foo = AtomicBool::new(false);
    assert_eq!(foo.fetch_nand(false, Ordering::SeqCst), false);
    assert_eq!(foo.load(Ordering::SeqCst), true);

#### `fn fetch_or(&self, val: bool, order: Ordering) -> bool`

Logical "or" with a boolean value.

Performs a logical "or" operation on the current value and the argument `val`, and sets the new value to the result.

Returns the previous value.

# Examples

    use std::sync::atomic::{AtomicBool, Ordering};

    let foo = AtomicBool::new(true);
    assert_eq!(foo.fetch_or(false, Ordering::SeqCst), true);
    assert_eq!(foo.load(Ordering::SeqCst), true);

    let foo = AtomicBool::new(true);
    assert_eq!(foo.fetch_or(true, Ordering::SeqCst), true);
    assert_eq!(foo.load(Ordering::SeqCst), true);

    let foo = AtomicBool::new(false);
    assert_eq!(foo.fetch_or(false, Ordering::SeqCst), false);
    assert_eq!(foo.load(Ordering::SeqCst), false);

#### `fn fetch_xor(&self, val: bool, order: Ordering) -> bool`

Logical "xor" with a boolean value.

Performs a logical "xor" operation on the current value and the argument `val`, and sets the new value to the result.

Returns the previous value.

# Examples

    use std::sync::atomic::{AtomicBool, Ordering};

    let foo = AtomicBool::new(true);
    assert_eq!(foo.fetch_xor(false, Ordering::SeqCst), true);
    assert_eq!(foo.load(Ordering::SeqCst), true);

    let foo = AtomicBool::new(true);
    assert_eq!(foo.fetch_xor(true, Ordering::SeqCst), true);
    assert_eq!(foo.load(Ordering::SeqCst), false);

    let foo = AtomicBool::new(false);
    assert_eq!(foo.fetch_xor(false, Ordering::SeqCst), false);
    assert_eq!(foo.load(Ordering::SeqCst), false);

## Trait Implementations

### `impl Default for AtomicBool`

#### `fn default() -> AtomicBool`

### `impl Sync for AtomicBool`

### `impl Debug for AtomicBool` 1.3.0

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

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