[][src]Struct spin::lazy::Lazy

pub struct Lazy<T, F = fn() -> T, R = Spin> { /* fields omitted */ }

A value which is initialized on the first access.

This type is a thread-safe Lazy, and can be used in statics.

Examples

use std::collections::HashMap;
use spin::Lazy;

static HASHMAP: Lazy<HashMap<i32, String>> = Lazy::new(|| {
    println!("initializing");
    let mut m = HashMap::new();
    m.insert(13, "Spica".to_string());
    m.insert(74, "Hoyten".to_string());
    m
});

fn main() {
    println!("ready");
    std::thread::spawn(|| {
        println!("{:?}", HASHMAP.get(&13));
    }).join().unwrap();
    println!("{:?}", HASHMAP.get(&74));

    // Prints:
    //   ready
    //   initializing
    //   Some("Spica")
    //   Some("Hoyten")
}

Implementations

impl<T, F, R> Lazy<T, F, R>[src]

pub const fn new(f: F) -> Self[src]

Creates a new lazy value with the given initializing function.

impl<T, F: FnOnce() -> T, R: RelaxStrategy> Lazy<T, F, R>[src]

pub fn force(this: &Self) -> &T[src]

Forces the evaluation of this lazy value and returns a reference to result. This is equivalent to the Deref impl, but is explicit.

Examples

use spin::Lazy;

let lazy = Lazy::new(|| 92);

assert_eq!(Lazy::force(&lazy), &92);
assert_eq!(&*lazy, &92);

Trait Implementations

impl<T: Debug, F, R> Debug for Lazy<T, F, R>[src]

impl<T: Default, R> Default for Lazy<T, fn() -> T, R>[src]

fn default() -> Self[src]

Creates a new lazy value using Default as the initializing function.

impl<T, F: FnOnce() -> T, R: RelaxStrategy> Deref for Lazy<T, F, R>[src]

type Target = T

The resulting type after dereferencing.

impl<T, F: Send> Sync for Lazy<T, F> where
    Once<T>: Sync
[src]

Auto Trait Implementations

impl<T, F, R> Send for Lazy<T, F, R> where
    F: Send,
    T: Send
[src]

impl<T, F = fn() -> T, R = Spin> !Sync for Lazy<T, F, R>[src]

impl<T, F, R> Unpin for Lazy<T, F, R> where
    F: Unpin,
    R: Unpin,
    T: Unpin
[src]

Blanket Implementations

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

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

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

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

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

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.

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.