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use std::rc::{Rc, Weak};
use std::cell::RefCell;
use std::fmt::{Pointer, Formatter, Result as FmtResult, Display, Error as FmtError};
use std::ops::Deref;
#[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Default)]
pub struct RcCell<T>(Rc<RefCell<T>>);
impl<T> RcCell<T> {
pub fn new(value: T) -> Self {
Self(Rc::new(RefCell::new(value)))
}
pub fn try_unwrap(this: Self) -> Result<T, Self> {
Rc::try_unwrap(this.0).map(RefCell::into_inner).map_err(Self)
}
pub fn downgrade(&self) -> RcCellWeak<T> {
RcCellWeak(Rc::downgrade(&self.0))
}
pub fn weak_count(&self) -> usize {
Rc::weak_count(&self.0)
}
pub fn strong_count(&self) -> usize {
Rc::strong_count(&self.0)
}
pub fn ptr_eq(&self, other: &Self) -> bool {
Rc::ptr_eq(&self.0, &other.0)
}
pub fn swap_with(&self, other: &Self) {
self.swap(&other.0)
}
}
impl<T> Deref for RcCell<T> {
type Target = RefCell<T>;
fn deref(&self) -> &Self::Target {
&*self.0
}
}
impl<T> From<T> for RcCell<T> {
fn from(t: T) -> Self {
Self::new(t)
}
}
impl<T> From<Box<T>> for RcCell<T> {
fn from(t: Box<T>) -> Self {
Self::new(*t)
}
}
impl<T> Pointer for RcCell<T> {
fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
write!(f, "{:p}", self.0)
}
}
impl<T> Display for RcCell<T> where T: Display {
fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
write!(f, "{}", self.0.try_borrow().map_err(|_| FmtError)?)
}
}
#[derive(Debug, Default, Clone)]
pub struct RcCellWeak<T>(Weak<RefCell<T>>);
impl<T> RcCellWeak<T> {
pub fn new() -> Self {
Self(Weak::new())
}
pub fn upgrade(&self) -> Option<RcCell<T>> {
self.0.upgrade().map(RcCell)
}
pub fn ptr_eq(&self, other: &Self) -> bool {
self.0.ptr_eq(&other.0)
}
}
#[cfg(test)]
mod tests {
use crate::RcCell;
#[test]
fn basic_test() {
let cell = RcCell::new("test");
let cell2 = cell.clone();
assert_eq!(cell.strong_count(), 2);
std::mem::drop(cell2);
assert_eq!(cell.strong_count(), 1);
}
}