proc_macro2/
rcvec.rs

1use alloc::rc::Rc;
2use alloc::vec;
3use core::mem;
4use core::panic::RefUnwindSafe;
5use core::slice;
6
7pub(crate) struct RcVec<T> {
8    inner: Rc<Vec<T>>,
9}
10
11pub(crate) struct RcVecBuilder<T> {
12    inner: Vec<T>,
13}
14
15pub(crate) struct RcVecMut<'a, T> {
16    inner: &'a mut Vec<T>,
17}
18
19#[derive(Clone)]
20pub(crate) struct RcVecIntoIter<T> {
21    inner: vec::IntoIter<T>,
22}
23
24impl<T> RcVec<T> {
25    pub(crate) fn is_empty(&self) -> bool {
26        self.inner.is_empty()
27    }
28
29    pub(crate) fn len(&self) -> usize {
30        self.inner.len()
31    }
32
33    pub(crate) fn iter(&self) -> slice::Iter<T> {
34        self.inner.iter()
35    }
36
37    pub(crate) fn make_mut(&mut self) -> RcVecMut<T>
38    where
39        T: Clone,
40    {
41        RcVecMut {
42            inner: Rc::make_mut(&mut self.inner),
43        }
44    }
45
46    pub(crate) fn get_mut(&mut self) -> Option<RcVecMut<T>> {
47        let inner = Rc::get_mut(&mut self.inner)?;
48        Some(RcVecMut { inner })
49    }
50
51    pub(crate) fn make_owned(mut self) -> RcVecBuilder<T>
52    where
53        T: Clone,
54    {
55        let vec = if let Some(owned) = Rc::get_mut(&mut self.inner) {
56            mem::take(owned)
57        } else {
58            Vec::clone(&self.inner)
59        };
60        RcVecBuilder { inner: vec }
61    }
62}
63
64impl<T> RcVecBuilder<T> {
65    pub(crate) fn new() -> Self {
66        RcVecBuilder { inner: Vec::new() }
67    }
68
69    pub(crate) fn with_capacity(cap: usize) -> Self {
70        RcVecBuilder {
71            inner: Vec::with_capacity(cap),
72        }
73    }
74
75    pub(crate) fn push(&mut self, element: T) {
76        self.inner.push(element);
77    }
78
79    pub(crate) fn extend(&mut self, iter: impl IntoIterator<Item = T>) {
80        self.inner.extend(iter);
81    }
82
83    pub(crate) fn as_mut(&mut self) -> RcVecMut<T> {
84        RcVecMut {
85            inner: &mut self.inner,
86        }
87    }
88
89    pub(crate) fn build(self) -> RcVec<T> {
90        RcVec {
91            inner: Rc::new(self.inner),
92        }
93    }
94}
95
96impl<'a, T> RcVecMut<'a, T> {
97    pub(crate) fn push(&mut self, element: T) {
98        self.inner.push(element);
99    }
100
101    pub(crate) fn extend(&mut self, iter: impl IntoIterator<Item = T>) {
102        self.inner.extend(iter);
103    }
104
105    pub(crate) fn pop(&mut self) -> Option<T> {
106        self.inner.pop()
107    }
108
109    pub(crate) fn as_mut(&mut self) -> RcVecMut<T> {
110        RcVecMut { inner: self.inner }
111    }
112}
113
114impl<T> Clone for RcVec<T> {
115    fn clone(&self) -> Self {
116        RcVec {
117            inner: Rc::clone(&self.inner),
118        }
119    }
120}
121
122impl<T> IntoIterator for RcVecBuilder<T> {
123    type Item = T;
124    type IntoIter = RcVecIntoIter<T>;
125
126    fn into_iter(self) -> Self::IntoIter {
127        RcVecIntoIter {
128            inner: self.inner.into_iter(),
129        }
130    }
131}
132
133impl<T> Iterator for RcVecIntoIter<T> {
134    type Item = T;
135
136    fn next(&mut self) -> Option<Self::Item> {
137        self.inner.next()
138    }
139
140    fn size_hint(&self) -> (usize, Option<usize>) {
141        self.inner.size_hint()
142    }
143}
144
145impl<T> RefUnwindSafe for RcVec<T> where T: RefUnwindSafe {}
proc_macro2/rcvec.rs

proc_macro2/
rcvec.rs
