unsized_stack/
iter.rs

1/*
2 * Created on Sat Jun 18 2022
3 *
4 * Copyright (c) storycraft. Licensed under the MIT Licence.
5 */
6
7use core::slice;
8use std::{marker::PhantomData, ptr::NonNull};
9
10use crate::raw::{self, RawUnsizedStack, TableItem};
11
12pub struct Iter<'a, T: ?Sized> {
13    base: NonNull<u8>,
14    table_iter: slice::Iter<'a, TableItem>,
15    _phantom: PhantomData<&'a T>,
16}
17
18impl<'a, T: ?Sized> Iter<'a, T> {
19    pub fn new(raw: &'a RawUnsizedStack<T>) -> Self {
20        Self {
21            base: raw.buf_ptr(),
22            table_iter: raw.table().iter(),
23            _phantom: PhantomData,
24        }
25    }
26
27    fn with_iter(
28        &mut self,
29        func: impl FnOnce(&mut slice::Iter<'a, TableItem>) -> Option<&'a TableItem>,
30    ) -> Option<&'a T> {
31        // Safety: pointer created with [`TableItem`] from table
32        Some(unsafe { &*raw::compose::<T>(self.base.as_ptr(), *func(&mut self.table_iter)?) })
33    }
34}
35
36impl<'a, T: ?Sized> Iterator for Iter<'a, T> {
37    type Item = &'a T;
38
39    fn next(&mut self) -> Option<Self::Item> {
40        self.with_iter(|iter| iter.next())
41    }
42
43    fn size_hint(&self) -> (usize, Option<usize>) {
44        self.table_iter.size_hint()
45    }
46
47    fn count(self) -> usize
48    where
49        Self: Sized,
50    {
51        self.table_iter.count()
52    }
53
54    fn nth(&mut self, n: usize) -> Option<Self::Item> {
55        self.with_iter(|iter| iter.nth(n))
56    }
57}
58
59impl<'a, T: 'a + ?Sized> DoubleEndedIterator for Iter<'a, T> {
60    fn next_back(&mut self) -> Option<Self::Item> {
61        self.with_iter(slice::Iter::next_back)
62    }
63
64    fn nth_back(&mut self, n: usize) -> Option<Self::Item> {
65        self.with_iter(|iter| iter.nth_back(n))
66    }
67}
68
69impl<'a, T: ?Sized> ExactSizeIterator for Iter<'a, T> {}
70
71pub struct IterMut<'a, T: ?Sized> {
72    base: NonNull<u8>,
73    table_iter: slice::Iter<'a, TableItem>,
74    _phantom: PhantomData<&'a mut T>,
75}
76
77impl<'a, T: ?Sized> IterMut<'a, T> {
78    pub fn new(raw: &'a mut RawUnsizedStack<T>) -> Self {
79        Self {
80            base: raw.buf_ptr(),
81            table_iter: raw.table().iter(),
82            _phantom: PhantomData,
83        }
84    }
85
86    fn with_iter(
87        &mut self,
88        func: impl FnOnce(&mut slice::Iter<'a, TableItem>) -> Option<&'a TableItem>,
89    ) -> Option<&'a mut T> {
90        // Safety: pointer created with [`TableItem`] from table
91        Some(unsafe {
92            &mut *raw::compose::<T>(self.base.as_ptr(), *func(&mut self.table_iter)?).cast_mut()
93        })
94    }
95}
96
97impl<'a, T: 'a + ?Sized> Iterator for IterMut<'a, T> {
98    type Item = &'a mut T;
99
100    fn next(&mut self) -> Option<Self::Item> {
101        self.with_iter(slice::Iter::next)
102    }
103
104    fn size_hint(&self) -> (usize, Option<usize>) {
105        self.table_iter.size_hint()
106    }
107
108    fn count(self) -> usize
109    where
110        Self: Sized,
111    {
112        self.table_iter.count()
113    }
114
115    fn nth(&mut self, n: usize) -> Option<Self::Item> {
116        self.with_iter(|iter| iter.nth(n))
117    }
118}
119
120impl<'a, T: ?Sized> DoubleEndedIterator for IterMut<'a, T> {
121    fn next_back(&mut self) -> Option<Self::Item> {
122        self.with_iter(slice::Iter::next_back)
123    }
124
125    fn nth_back(&mut self, n: usize) -> Option<Self::Item> {
126        self.with_iter(|iter| iter.nth_back(n))
127    }
128}
129
130impl<'a, T: ?Sized> ExactSizeIterator for IterMut<'a, T> {}