Struct CallOnce

pub struct CallOnce { /* private fields */ }

A type that can only be called successfully once.

This is a simple wrapper around an AtomicBool with a more descriptive API.

While CallOnce is synchronized and thread-safe, it does not synchronize other memory accesses.

Examples

use call_once::CallOnce;

static CALL_ONCE: CallOnce = CallOnce::new();

assert!(CALL_ONCE.call_once().is_ok());
assert!(CALL_ONCE.call_once().is_err());

Implementations

impl CallOnce

pub const fn new() -> Self

Creates a new CallOnce.

Examples

use call_once::CallOnce;

let call_once = CallOnce::new();

pub fn call_once(&self) -> Result<(), CallOnceError>

Mark this CallOnce as called.

Only the first call returns Ok. All subsequent calls return Err.

Examples

use call_once::CallOnce;

let call_once = CallOnce::new();

assert!(call_once.call_once().is_ok());
assert!(call_once.call_once().is_err());

pub fn was_called(&self) -> bool

Returns true if call_once has been called.

Examples

use call_once::CallOnce;

let call_once = CallOnce::new();
assert!(!call_once.was_called());

call_once.call_once().unwrap();
assert!(call_once.was_called());

Trait Implementations

impl Debug for CallOnce

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for CallOnce

fn default() -> CallOnce

Returns the “default value” for a type.