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mod arc_block;
mod arc_buffer;
use arc_block::*;
pub use arc_buffer::*;
use std::{alloc::Layout, marker::PhantomData, ops::Deref, ptr::write};
#[derive(Debug)]
#[repr(C)]
pub struct Arc<T> {
block: ArcBlock,
phantom: PhantomData<T>,
}
impl<T> Arc<T> {
pub fn new(payload: T) -> Self {
let mut block = ArcBlock::new(Layout::new::<T>());
unsafe {
write(block.ptr_mut() as *mut T, payload);
}
Self {
block,
phantom: PhantomData::default(),
}
}
}
impl<T> From<T> for Arc<T> {
fn from(payload: T) -> Self {
Self::new(payload)
}
}
impl<T> Deref for Arc<T> {
type Target = T;
fn deref(&self) -> &T {
unsafe { &*(self.block.ptr() as *const T) }
}
}
impl<T> Clone for Arc<T> {
fn clone(&self) -> Self {
Self {
block: self.block.clone(),
phantom: PhantomData::default(),
}
}
}
impl<T> Drop for Arc<T> {
fn drop(&mut self) {
self.block.drop::<T>();
}
}
impl<T: Default> Default for Arc<T> {
fn default() -> Self {
Self::new(T::default())
}
}
#[cfg(test)]
mod tests {
use super::*;
use std::mem::{drop, forget};
#[test]
fn create() {
Arc::new(0);
}
#[test]
fn clone() {
let arc = Arc::new(0);
drop(arc.clone());
drop(arc);
}
#[test]
fn new_box() {
forget(Arc::new(Box::new(0)));
}
#[test]
fn clone_box() {
let x = Arc::new(Box::new(0));
forget(x.clone());
forget(x);
}
#[test]
fn drop_box() {
Arc::new(Box::new(0));
}
#[test]
fn load_payload() {
assert_eq!(*Arc::new(42), 42);
}
mod zero_sized {
use super::*;
#[test]
fn create() {
Arc::new(());
}
#[test]
fn clone() {
let arc = Arc::new(());
drop(arc.clone());
drop(arc);
}
#[test]
#[allow(clippy::unit_cmp)]
fn load_payload() {
assert_eq!(*Arc::new(()), ());
}
}
}