Merge pull request #500 from Nitrokey/vec-drain-generic

Implement `Vec::drain`, `as_(mut_)view` on the `*Inner` types, generic over `Storage`

Author: reitermarkus

src/binary_heap.rs

@@ -184,14 +184,16 @@ impl<T, K, const N: usize> BinaryHeap<T, K, N> {
     pub fn into_vec(self) -> Vec<T, N> {
         self.data
     }
+}
 
+impl<T, K, S: VecStorage<T>> BinaryHeapInner<T, K, S> {
     /// Get a reference to the `BinaryHeap`, erasing the `N` const-generic.
     pub fn as_view(&self) -> &BinaryHeapView<T, K> {
-        self
+        S::as_binary_heap_view(self)
     }
     /// Get a mutable reference to the `BinaryHeap`, erasing the `N` const-generic.
     pub fn as_mut_view(&mut self) -> &mut BinaryHeapView<T, K> {
-        self
+        S::as_binary_heap_mut_view(self)
     }
 }
 

src/defmt.rs

@@ -1,7 +1,7 @@
 //! Defmt implementations for heapless types
 
 use crate::{
-    string::StringInner,
+    string::{StringInner, StringStorage},
     vec::{VecInner, VecStorage},
 };
 use defmt::Formatter;
@@ -15,7 +15,7 @@ where
     }
 }
 
-impl<S: VecStorage<u8> + ?Sized> defmt::Format for StringInner<S>
+impl<S: StringStorage + ?Sized> defmt::Format for StringInner<S>
 where
     u8: defmt::Format,
 {

src/deque.rs

@@ -186,19 +186,19 @@ impl<T, const N: usize> Deque<T, N> {
             self.back - self.front
         }
     }
+}
 
+impl<T, S: VecStorage<T> + ?Sized> DequeInner<T, S> {
     /// Get a reference to the `Deque`, erasing the `N` const-generic.
     pub fn as_view(&self) -> &DequeView<T> {
-        self
+        S::as_deque_view(self)
     }
 
     /// Get a mutable reference to the `Deque`, erasing the `N` const-generic.
     pub fn as_mut_view(&mut self) -> &mut DequeView<T> {
-        self
+        S::as_deque_mut_view(self)
     }
-}
 
-impl<T, S: VecStorage<T> + ?Sized> DequeInner<T, S> {
     /// Returns the maximum number of elements the deque can hold.
     pub fn storage_capacity(&self) -> usize {
         self.buffer.borrow().len()

src/histbuf.rs

@@ -41,6 +41,8 @@ use core::slice;
 mod storage {
     use core::mem::MaybeUninit;
 
+    use super::{HistoryBufferInner, HistoryBufferView};
+
     /// Trait defining how data for a container is stored.
     ///
     /// There's two implementations available:
@@ -72,6 +74,14 @@ mod storage {
         // part of the sealed trait so that no trait is publicly implemented by `OwnedHistBufStorage` besides `Storage`
         fn borrow(&self) -> &[MaybeUninit<T>];
         fn borrow_mut(&mut self) -> &mut [MaybeUninit<T>];
+        fn as_hist_buf_view(this: &HistoryBufferInner<T, Self>) -> &HistoryBufferView<T>
+        where
+            Self: HistBufStorage<T>;
+        fn as_hist_buf_mut_view(
+            this: &mut HistoryBufferInner<T, Self>,
+        ) -> &mut HistoryBufferView<T>
+        where
+            Self: HistBufStorage<T>;
     }
 
     // One sealed layer of indirection to hide the internal details (The MaybeUninit).
@@ -91,6 +101,18 @@ mod storage {
         fn borrow_mut(&mut self) -> &mut [MaybeUninit<T>] {
             &mut self.buffer
         }
+        fn as_hist_buf_view(this: &HistoryBufferInner<T, Self>) -> &HistoryBufferView<T>
+        where
+            Self: HistBufStorage<T>,
+        {
+            this
+        }
+        fn as_hist_buf_mut_view(this: &mut HistoryBufferInner<T, Self>) -> &mut HistoryBufferView<T>
+        where
+            Self: HistBufStorage<T>,
+        {
+            this
+        }
     }
     impl<T, const N: usize> HistBufStorage<T> for OwnedHistBufStorage<T, N> {}
 
@@ -101,6 +123,18 @@ mod storage {
         fn borrow_mut(&mut self) -> &mut [MaybeUninit<T>] {
             &mut self.buffer
         }
+        fn as_hist_buf_view(this: &HistoryBufferInner<T, Self>) -> &HistoryBufferView<T>
+        where
+            Self: HistBufStorage<T>,
+        {
+            this
+        }
+        fn as_hist_buf_mut_view(this: &mut HistoryBufferInner<T, Self>) -> &mut HistoryBufferView<T>
+        where
+            Self: HistBufStorage<T>,
+        {
+            this
+        }
     }
     impl<T> HistBufStorage<T> for ViewHistBufStorage<T> {}
 }
@@ -221,18 +255,6 @@ impl<T, const N: usize> HistoryBuffer<T, N> {
             filled: false,
         }
     }
-
-    /// Get a reference to the `HistoryBuffer`, erasing the `N` const-generic.
-    #[inline]
-    pub const fn as_view(&self) -> &HistoryBufferView<T> {
-        self
-    }
-
-    /// Get a mutable reference to the `HistoryBuffer`, erasing the `N` const-generic.
-    #[inline]
-    pub fn as_mut_view(&mut self) -> &mut HistoryBufferView<T> {
-        self
-    }
 }
 
 impl<T, const N: usize> HistoryBuffer<T, N>
@@ -264,6 +286,17 @@ where
     }
 }
 impl<T: Copy, S: HistBufStorage<T> + ?Sized> HistoryBufferInner<T, S> {
+    /// Get a reference to the `HistoryBuffer`, erasing the `N` const-generic.
+    #[inline]
+    pub fn as_view(&self) -> &HistoryBufferView<T> {
+        S::as_hist_buf_view(self)
+    }
+
+    /// Get a mutable reference to the `HistoryBuffer`, erasing the `N` const-generic.
+    #[inline]
+    pub fn as_mut_view(&mut self) -> &mut HistoryBufferView<T> {
+        S::as_hist_buf_mut_view(self)
+    }
     /// Clears the buffer, replacing every element with the given value.
     pub fn clear_with(&mut self, t: T) {
         // SAFETY: we reset the values just after

src/lib.rs

@@ -181,6 +181,11 @@ pub mod storage;
 pub mod string;
 pub mod vec;
 
+// Workaround a compiler ICE in rust 1.83 to 1.86
+// https://github.com/rust-lang/rust/issues/138979#issuecomment-2760839948
+#[expect(dead_code)]
+fn dead_code_ice_workaround() {}
+
 #[cfg(feature = "serde")]
 mod de;
 #[cfg(feature = "serde")]

src/linear_map.rs

@@ -4,22 +4,103 @@
 
 use core::{borrow::Borrow, fmt, mem, ops, slice};
 
-use crate::vec::{OwnedVecStorage, Vec, VecInner, VecStorage, ViewVecStorage};
+use crate::vec::{OwnedVecStorage, Vec, VecInner, ViewVecStorage};
+
+mod storage {
+    use crate::vec::{OwnedVecStorage, VecStorage, ViewVecStorage};
+
+    use super::{LinearMapInner, LinearMapView};
+
+    /// Trait defining how data for a [`LinearMap`](super::LinearMap) is stored.
+    ///
+    /// There's two implementations available:
+    ///
+    /// - [`OwnedStorage`]: stores the data in an array whose size is known at compile time.
+    /// - [`ViewStorage`]: stores the data in an unsized slice
+    ///
+    /// This allows [`LinearMap`] to be generic over either sized or unsized storage. The [`linear_map`](super)
+    /// module contains a [`LinearMapInner`] struct that's generic on [`LinearMapStorage`],
+    /// and two type aliases for convenience:
+    ///
+    /// - [`LinearMap<N>`](crate::linear_map::LinearMap) = `LinearMapInner<OwnedStorage<u8, N>>`
+    /// - [`LinearMapView<T>`](crate::linear_map::LinearMapView) = `LinearMapInner<ViewStorage<u8>>`
+    ///
+    /// `LinearMap` can be unsized into `StrinsgView`, either by unsizing coercions such as `&mut LinearMap -> &mut LinearMapView` or
+    /// `Box<LinearMap> -> Box<LinearMapView>`, or explicitly with [`.as_view()`](crate::linear_map::LinearMap::as_view) or [`.as_mut_view()`](crate::linear_map::LinearMap::as_mut_view).
+    ///
+    /// This trait is sealed, so you cannot implement it for your own types. You can only use
+    /// the implementations provided by this crate.
+    ///
+    /// [`LinearMapInner`]: super::LinearMapInner
+    /// [`LinearMap`]: super::LinearMap
+    /// [`OwnedStorage`]: super::OwnedStorage
+    /// [`ViewStorage`]: super::ViewStorage
+    pub trait LinearMapStorage<K, V>: LinearMapStorageSealed<K, V> {}
+    pub trait LinearMapStorageSealed<K, V>: VecStorage<(K, V)> {
+        fn as_linear_map_view(this: &LinearMapInner<K, V, Self>) -> &LinearMapView<K, V>
+        where
+            Self: LinearMapStorage<K, V>;
+        fn as_linear_map_mut_view(
+            this: &mut LinearMapInner<K, V, Self>,
+        ) -> &mut LinearMapView<K, V>
+        where
+            Self: LinearMapStorage<K, V>;
+    }
+
+    impl<K, V, const N: usize> LinearMapStorage<K, V> for OwnedVecStorage<(K, V), N> {}
+    impl<K, V, const N: usize> LinearMapStorageSealed<K, V> for OwnedVecStorage<(K, V), N> {
+        fn as_linear_map_view(this: &LinearMapInner<K, V, Self>) -> &LinearMapView<K, V>
+        where
+            Self: LinearMapStorage<K, V>,
+        {
+            this
+        }
+        fn as_linear_map_mut_view(this: &mut LinearMapInner<K, V, Self>) -> &mut LinearMapView<K, V>
+        where
+            Self: LinearMapStorage<K, V>,
+        {
+            this
+        }
+    }
+
+    impl<K, V> LinearMapStorage<K, V> for ViewVecStorage<(K, V)> {}
+
+    impl<K, V> LinearMapStorageSealed<K, V> for ViewVecStorage<(K, V)> {
+        fn as_linear_map_view(this: &LinearMapInner<K, V, Self>) -> &LinearMapView<K, V>
+        where
+            Self: LinearMapStorage<K, V>,
+        {
+            this
+        }
+        fn as_linear_map_mut_view(this: &mut LinearMapInner<K, V, Self>) -> &mut LinearMapView<K, V>
+        where
+            Self: LinearMapStorage<K, V>,
+        {
+            this
+        }
+    }
+}
+
+pub use storage::LinearMapStorage;
+/// Implementation of [`LinearMapStorage`] that stores the data in an array whose size is known at compile time.
+pub type OwnedStorage<K, V, const N: usize> = OwnedVecStorage<(K, V), N>;
+/// Implementation of [`LinearMapStorage`] that stores the data in an unsized slice.
+pub type ViewStorage<K, V> = ViewVecStorage<(K, V)>;
 
 /// Base struct for [`LinearMap`] and [`LinearMapView`]
-pub struct LinearMapInner<K, V, S: VecStorage<(K, V)> + ?Sized> {
+pub struct LinearMapInner<K, V, S: LinearMapStorage<K, V> + ?Sized> {
     pub(crate) buffer: VecInner<(K, V), S>,
 }
 
 /// A fixed capacity map/dictionary that performs lookups via linear search.
 ///
 /// Note that as this map doesn't use hashing so most operations are *O*(n) instead of *O*(1).
-pub type LinearMap<K, V, const N: usize> = LinearMapInner<K, V, OwnedVecStorage<(K, V), N>>;
+pub type LinearMap<K, V, const N: usize> = LinearMapInner<K, V, OwnedStorage<K, V, N>>;
 
 /// A dynamic capacity map/dictionary that performs lookups via linear search.
 ///
 /// Note that as this map doesn't use hashing so most operations are *O*(n) instead of *O*(1).
-pub type LinearMapView<K, V> = LinearMapInner<K, V, ViewVecStorage<(K, V)>>;
+pub type LinearMapView<K, V> = LinearMapInner<K, V, ViewStorage<K, V>>;
 
 impl<K, V, const N: usize> LinearMap<K, V, N> {
     /// Creates an empty `LinearMap`.
@@ -38,22 +119,22 @@ impl<K, V, const N: usize> LinearMap<K, V, N> {
     pub const fn new() -> Self {
         Self { buffer: Vec::new() }
     }
+}
 
+impl<K, V, S: LinearMapStorage<K, V> + ?Sized> LinearMapInner<K, V, S>
+where
+    K: Eq,
+{
     /// Get a reference to the `LinearMap`, erasing the `N` const-generic.
     pub fn as_view(&self) -> &LinearMapView<K, V> {
-        self
+        S::as_linear_map_view(self)
     }
 
     /// Get a mutable reference to the `LinearMap`, erasing the `N` const-generic.
     pub fn as_mut_view(&mut self) -> &mut LinearMapView<K, V> {
-        self
+        S::as_linear_map_mut_view(self)
     }
-}
 
-impl<K, V, S: VecStorage<(K, V)> + ?Sized> LinearMapInner<K, V, S>
-where
-    K: Eq,
-{
     /// Returns the number of elements that the map can hold.
     ///
     /// Computes in *O*(1) time.
@@ -388,7 +469,7 @@ where
     }
 }
 
-impl<K, V, Q, S: VecStorage<(K, V)> + ?Sized> ops::Index<&'_ Q> for LinearMapInner<K, V, S>
+impl<K, V, Q, S: LinearMapStorage<K, V> + ?Sized> ops::Index<&'_ Q> for LinearMapInner<K, V, S>
 where
     K: Borrow<Q> + Eq,
     Q: Eq + ?Sized,
@@ -400,7 +481,7 @@ where
     }
 }
 
-impl<K, V, Q, S: VecStorage<(K, V)> + ?Sized> ops::IndexMut<&'_ Q> for LinearMapInner<K, V, S>
+impl<K, V, Q, S: LinearMapStorage<K, V> + ?Sized> ops::IndexMut<&'_ Q> for LinearMapInner<K, V, S>
 where
     K: Borrow<Q> + Eq,
     Q: Eq + ?Sized,
@@ -431,7 +512,7 @@ where
     }
 }
 
-impl<K, V, S: VecStorage<(K, V)> + ?Sized> fmt::Debug for LinearMapInner<K, V, S>
+impl<K, V, S: LinearMapStorage<K, V> + ?Sized> fmt::Debug for LinearMapInner<K, V, S>
 where
     K: Eq + fmt::Debug,
     V: fmt::Debug,
@@ -489,7 +570,7 @@ where
     }
 }
 
-impl<'a, K, V, S: VecStorage<(K, V)> + ?Sized> IntoIterator for &'a LinearMapInner<K, V, S>
+impl<'a, K, V, S: LinearMapStorage<K, V> + ?Sized> IntoIterator for &'a LinearMapInner<K, V, S>
 where
     K: Eq,
 {
@@ -533,7 +614,7 @@ impl<'a, K, V> Iterator for IterMut<'a, K, V> {
     }
 }
 
-impl<K, V, S1: VecStorage<(K, V)> + ?Sized, S2: VecStorage<(K, V)> + ?Sized>
+impl<K, V, S1: LinearMapStorage<K, V> + ?Sized, S2: LinearMapStorage<K, V> + ?Sized>
     PartialEq<LinearMapInner<K, V, S2>> for LinearMapInner<K, V, S1>
 where
     K: Eq,
@@ -547,7 +628,7 @@ where
     }
 }
 
-impl<K, V, S: VecStorage<(K, V)> + ?Sized> Eq for LinearMapInner<K, V, S>
+impl<K, V, S: LinearMapStorage<K, V> + ?Sized> Eq for LinearMapInner<K, V, S>
 where
     K: Eq,
     V: PartialEq,