sealed: add more functions

src/sealed/mod.rs

@@ -0,0 +1,8 @@
+//! Collections that never leak references to their content, and therefore can be safely accessed via shared references.
+
+mod queue;
+mod set;
+mod utils;
+
+pub use queue::Queue;
+pub use set::Set;

src/sealed/queue.rs

@@ -0,0 +1,121 @@
+use super::utils::UnsafeWrapper;
+use std::collections::{VecDeque, vec_deque};
+use std::fmt;
+
+/// FIFO queue that never leaks references to its content
+pub struct Queue<T>(UnsafeWrapper<VecDeque<T>>);
+
+impl<T> Queue<T> {
+    pub fn new() -> Self {
+        Self(UnsafeWrapper::new(VecDeque::new()))
+    }
+
+    pub fn with_capacity(capacity: usize) -> Self {
+        Self(UnsafeWrapper::new(VecDeque::with_capacity(capacity)))
+    }
+
+    pub fn push(&self, item: T) {
+        // SAFETY: `with()` is never invoked recursively
+        unsafe { self.0.with(|inner| inner.push_back(item)) }
+    }
+
+    pub fn pop(&self) -> Option<T> {
+        // SAFETY: `with()` is never invoked recursively
+        unsafe { self.0.with(|inner| inner.pop_front()) }
+    }
+
+    pub fn contains(&self, item: &T) -> bool
+    where
+        T: PartialEq<T>,
+    {
+        // SAFETY: `with()` is never invoked recursively
+        unsafe { self.0.with(|inner| inner.contains(item)) }
+    }
+
+    pub fn remove_all(&self, item: &T) -> bool
+    where
+        T: PartialEq<T>,
+    {
+        // SAFETY: `with()` is never invoked recursively
+        unsafe {
+            self.0.with(|inner| {
+                let initial_len = inner.len();
+                inner.retain(|e| e != item);
+                inner.len() != initial_len
+            })
+        }
+    }
+
+    pub fn clear(&self) {
+        // SAFETY: `with()` is never invoked recursively
+        unsafe { self.0.with(|inner| inner.clear()) }
+    }
+
+    pub fn len(&self) -> usize {
+        // SAFETY: `with()` is never invoked recursively
+        unsafe { self.0.with(|inner| inner.len()) }
+    }
+
+    pub fn capacity(&self) -> usize {
+        // SAFETY: `with()` is never invoked recursively
+        unsafe { self.0.with(|inner| inner.capacity()) }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
+    pub fn into_inner(self) -> VecDeque<T> {
+        self.0.into_inner()
+    }
+}
+
+impl<T> From<VecDeque<T>> for Queue<T> {
+    fn from(vec_deque: VecDeque<T>) -> Self {
+        Self(UnsafeWrapper::new(vec_deque))
+    }
+}
+
+impl<T: fmt::Debug> fmt::Debug for Queue<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        // SAFETY: `with()` is never invoked recursively
+        unsafe { self.0.with(|inner| inner.fmt(f)) }
+    }
+}
+
+impl<T> Default for Queue<T> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<T: Clone> Clone for Queue<T> {
+    fn clone(&self) -> Self {
+        // SAFETY: `with()` is never invoked recursively
+        unsafe { self.0.with(|inner| Self(UnsafeWrapper::new(inner.clone()))) }
+    }
+}
+
+impl<T> IntoIterator for Queue<T> {
+    type Item = T;
+    type IntoIter = vec_deque::IntoIter<T>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.0.into_inner().into_iter()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use static_assertions::{assert_impl_all, assert_not_impl_any};
+    use std::{rc::Rc, sync::Arc};
+
+    #[test]
+    fn test_queue_is_send_but_not_sync() {
+        assert_impl_all!(Queue<usize>: std::marker::Send);
+        assert_not_impl_any!(Queue<Rc<usize>>: std::marker::Send);
+        assert_not_impl_any!(Queue<Arc<usize>>: Sync);
+        assert_not_impl_any!(Arc<Queue<usize>>: std::marker::Send, Sync);
+    }
+}