// SPDX-License-Identifier: Apache-2.0 OR MIT use alloc::rc::Rc;use alloc::vec;use core::mem;use core::panic::RefUnwindSafe;use core::slice; pub(crate) struct RcVec<T> {    inner: Rc<Vec<T>>,} pub(crate) struct RcVecBuilder<T> {    inner: Vec<T>,} pub(crate) struct RcVecMut<'a, T> {    inner: &'a mut Vec<T>,} #[derive(Clone)]pub(crate) struct RcVecIntoIter<T> {    inner: vec::IntoIter<T>,} impl<T> RcVec<T> {    pub(crate) fn is_empty(&self) -> bool {        self.inner.is_empty()    }     pub(crate) fn len(&self) -> usize {        self.inner.len()    }     pub(crate) fn iter(&self) -> slice::Iter<T> {        self.inner.iter()    }     pub(crate) fn make_mut(&mut self) -> RcVecMut<T>    where        T: Clone,    {        RcVecMut {            inner: Rc::make_mut(&mut self.inner),        }    }     pub(crate) fn get_mut(&mut self) -> Option<RcVecMut<T>> {        let inner = Rc::get_mut(&mut self.inner)?;        Some(RcVecMut { inner })    }     pub(crate) fn make_owned(mut self) -> RcVecBuilder<T>    where        T: Clone,    {        let vec = if let Some(owned) = Rc::get_mut(&mut self.inner) {            mem::take(owned)        } else {            Vec::clone(&self.inner)        };        RcVecBuilder { inner: vec }    }} impl<T> RcVecBuilder<T> {    pub(crate) fn new() -> Self {        RcVecBuilder { inner: Vec::new() }    }     pub(crate) fn with_capacity(cap: usize) -> Self {        RcVecBuilder {            inner: Vec::with_capacity(cap),        }    }     pub(crate) fn push(&mut self, element: T) {        self.inner.push(element);    }     pub(crate) fn extend(&mut self, iter: impl IntoIterator<Item = T>) {        self.inner.extend(iter);    }     pub(crate) fn as_mut(&mut self) -> RcVecMut<T> {        RcVecMut {            inner: &mut self.inner,        }    }     pub(crate) fn build(self) -> RcVec<T> {        RcVec {            inner: Rc::new(self.inner),        }    }} impl<'a, T> RcVecMut<'a, T> {    pub(crate) fn push(&mut self, element: T) {        self.inner.push(element);    }     pub(crate) fn extend(&mut self, iter: impl IntoIterator<Item = T>) {        self.inner.extend(iter);    }     pub(crate) fn as_mut(&mut self) -> RcVecMut<T> {        RcVecMut { inner: self.inner }    }     pub(crate) fn take(self) -> RcVecBuilder<T> {        let vec = mem::take(self.inner);        RcVecBuilder { inner: vec }    }} impl<T> Clone for RcVec<T> {    fn clone(&self) -> Self {        RcVec {            inner: Rc::clone(&self.inner),        }    }} impl<T> IntoIterator for RcVecBuilder<T> {    type Item = T;    type IntoIter = RcVecIntoIter<T>;     fn into_iter(self) -> Self::IntoIter {        RcVecIntoIter {            inner: self.inner.into_iter(),        }    }} impl<T> Iterator for RcVecIntoIter<T> {    type Item = T;     fn next(&mut self) -> Option<Self::Item> {        self.inner.next()    }     fn size_hint(&self) -> (usize, Option<usize>) {        self.inner.size_hint()    }} impl<T> RefUnwindSafe for RcVec<T> where T: RefUnwindSafe {}