Struct QuickBool

Source

pub struct QuickBool { /* private fields */ }

Expand description

A lock-free boolean implementation using atomic operations.

This type represents a 3-way boolean state:

Unset: The value hasn’t been evaluated yet
True: The value is true
False: The value is false

Once set to true or false, the value cannot be changed, making it effectively immutable after initialization.

Implementations§

Source §

impl QuickBool

Source

pub const fn new() -> Self

Creates a new QuickBool in the unset state.

Source

pub fn get_or_set<F>(&self, f: F) -> bool
where F: FnOnce() -> bool,

Gets the current value, evaluating the closure if the value is unset.

This method is lock-free and will only evaluate the closure once. Subsequent calls will return the cached value.

§Arguments

f - A closure that returns a boolean value

§Returns

The boolean value, either from cache or newly computed

§Example

use quick_bool::QuickBool;
 
let quick_bool = QuickBool::new();
let value = quick_bool.get_or_set(|| {
    // This expensive computation only happens once
    std::thread::sleep(std::time::Duration::from_millis(100));
    true
});
 
// Second call returns immediately without computation
let cached_value = quick_bool.get_or_set(|| panic!("This won't execute"));
assert_eq!(value, cached_value);

Source

pub fn get(&self) -> Option<bool>

Gets the current value without computing it.

Returns None if the value is unset, Some(true) if true, or Some(false) if false.

§Example

use quick_bool::QuickBool;
 
let quick_bool = QuickBool::new();
assert_eq!(quick_bool.get(), None);
 
quick_bool.get_or_set(|| true);
assert_eq!(quick_bool.get(), Some(true));

Source

pub fn is_set(&self) -> bool

Checks if the value has been set.

Returns true if the value is either true or false, false if it’s still unset.

§Example

use quick_bool::QuickBool;
 
let quick_bool = QuickBool::new();
assert!(!quick_bool.is_set());
 
quick_bool.get_or_set(|| true);
assert!(quick_bool.is_set());

Source

pub fn reset(&self)

Resets the value back to unset state.

This allows the value to be recomputed on the next call to get_or_set.

§Example

use quick_bool::QuickBool;
 
let quick_bool = QuickBool::new();
quick_bool.get_or_set(|| true);
assert!(quick_bool.is_set());
 
quick_bool.reset();
assert!(!quick_bool.is_set());