blob: c67a3018908559775bb9998fb31e235c1759b71d [file] [log] [blame]
// Copyright 2016 lazy-static.rs Developers
//
// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
// http://opensource.org/licenses/MIT>, at your option. This file may not be
// copied, modified, or distributed except according to those terms.
extern crate std;
use self::std::prelude::v1::*;
use self::std::sync::Once;
pub use self::std::sync::ONCE_INIT;
pub struct Lazy<T: Sync>(*const T, Once);
impl<T: Sync> Lazy<T> {
pub const INIT: Self = Lazy(0 as *const T, ONCE_INIT);
#[inline(always)]
pub fn get<F>(&'static mut self, f: F) -> &T
where
F: FnOnce() -> T,
{
unsafe {
let r = &mut self.0;
self.1.call_once(|| {
*r = Box::into_raw(Box::new(f()));
});
&*self.0
}
}
}
unsafe impl<T: Sync> Sync for Lazy<T> {}
#[macro_export]
#[doc(hidden)]
macro_rules! __lazy_static_create {
($NAME:ident, $T:ty) => {
static mut $NAME: $crate::lazy::Lazy<$T> = $crate::lazy::Lazy::INIT;
};
}