Struct ethers::contract::Lazy [−]
pub struct Lazy<T, F = fn() -> T> { /* fields omitted */ }
Expand description
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>
pub fn into_value(this: Lazy<T, F>) -> Result<T, F>
pub fn into_value(this: Lazy<T, F>) -> Result<T, F>
Consumes this Lazy
returning the stored value.
Returns Ok(value)
if Lazy
is initialized and Err(f)
otherwise.
Trait Implementations
Auto Trait Implementations
impl<T, F> UnwindSafe for Lazy<T, F> where
F: UnwindSafe,
T: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more
Instruments this type with the provided Span
, returning an
Instrumented
wrapper. Read more
pub fn vzip(self) -> V
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more