[−]Struct geng::prelude::once_cell::sync::Lazy
A value which is initialized on the first access.
This type is thread-safe and can be used in statics.
Example
use std::collections::HashMap; use once_cell::sync::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> Lazy<T, F>
impl<T, F> Lazy<T, F> where
F: FnOnce() -> T,
F: FnOnce() -> T,
pub fn force(this: &Lazy<T, F>) -> &Tⓘ
Forces the evaluation of this lazy value and
returns a reference to the result. This is equivalent
to the Deref
impl, but is explicit.
Example
use once_cell::sync::Lazy; let lazy = Lazy::new(|| 92); assert_eq!(Lazy::force(&lazy), &92); assert_eq!(&*lazy, &92);
Trait Implementations
impl<T, F> Debug for Lazy<T, F> where
T: Debug,
T: Debug,
impl<T> Default for Lazy<T, fn() -> T> where
T: Default,
T: Default,
pub fn default() -> Lazy<T, fn() -> T>
Creates a new lazy value using Default
as the initializing function.
impl<T, F> Deref for Lazy<T, F> where
F: FnOnce() -> T,
F: FnOnce() -> T,
impl<T, F> DerefMut for Lazy<T, F> where
F: FnOnce() -> T,
F: FnOnce() -> T,
impl<T, F> RefUnwindSafe for Lazy<T, F> where
F: RefUnwindSafe,
OnceCell<T>: RefUnwindSafe,
F: RefUnwindSafe,
OnceCell<T>: RefUnwindSafe,
impl<T, F> Sync for Lazy<T, F> where
F: Send,
OnceCell<T>: Sync,
F: Send,
OnceCell<T>: Sync,
Auto Trait Implementations
impl<T, F> Send for Lazy<T, F> where
F: Send,
T: Send,
F: Send,
T: Send,
impl<T, F> Unpin for Lazy<T, F> where
F: Unpin,
T: Unpin,
F: Unpin,
T: Unpin,
impl<T, F> UnwindSafe for Lazy<T, F> where
F: UnwindSafe,
T: UnwindSafe,
F: UnwindSafe,
T: UnwindSafe,
Blanket Implementations
impl<T> Any for T where
T: 'static + ?Sized,
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T: 'static + ?Sized,
impl<T> Borrow<T> for T where
T: ?Sized,
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T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
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T: ?Sized,
pub fn borrow_mut(&mut self) -> &mut Tⓘ
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impl<T> From<T> for T
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impl<T, U> Into<U> for T where
U: From<T>,
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U: From<T>,
impl<T> Pointable for T
pub const ALIGN: usize
type Init = T
The type for initializers.
pub unsafe fn init(init: <T as Pointable>::Init) -> usize
pub unsafe fn deref<'a>(ptr: usize) -> &'a Tⓘ
pub unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut Tⓘ
pub unsafe fn drop(ptr: usize)
impl<T> Same<T> for T
type Output = T
Should always be Self
impl<T, U> TryFrom<U> for T where
U: Into<T>,
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U: Into<T>,
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>
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impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
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U: TryFrom<T>,
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>
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impl<V, T> VZip<V> for T where
V: MultiLane<T>,
V: MultiLane<T>,