This commit is contained in:
Lokathor
2020-01-24 02:38:18 -07:00
parent b2a9fe8e80
commit 9459d40649
2 changed files with 167 additions and 107 deletions
+160 -98
View File
@@ -32,12 +32,55 @@ macro_rules! array_vec {
};
}
/// An array-backed vector-like data structure.
/// An array-backed, vector-like data structure.
///
/// * Fixed capacity (based on array size).
/// * Variable length.
/// * All of the array memory is always "initialized" in the init/uninit memory
/// sense.
/// * `ArrayVec` has a fixed capacity, equal to the array size.
/// * `ArrayVec` has a variable length, as you add and remove elements. Attempts
/// to fill the vec beyond its capacity will cause a panic.
/// * All of the vec's array slots are always initialized in terms of Rust's
/// memory model. When you remove a element from a location, the old value at
/// that location is replaced with the type's default value.
///
/// The overall API of this type is intended to, as much as possible, emulate
/// the API of the [`Vec`](https://doc.rust-lang.org/alloc/vec/struct.Vec.html)
/// type.
///
/// ## Construction
///
/// If the backing array supports Default (length 32 or less), then you can use
/// the `array_vec!` macro similarly to how you might use the `vec!` macro.
/// Specify the array type, then optionally give all the initial values you want
/// to have.
/// ```rust
/// # use tinyvec::*;
/// let some_ints = array_vec!([i32; 4], 1, 2, 3);
/// assert_eq!(some_ints.len(), 3);
/// ```
///
/// The [`default`](ArrayVec::<A>::new) for an `ArrayVec` is to have a default
/// array with length 0. The [`new`](ArrayVec::<A>::new) method is the same as
/// calling `default`
/// ```rust
/// # use tinyvec::*;
/// let some_ints = ArrayVec::<[i32; 7]>::default();
/// assert_eq!(some_ints.len(), 0);
///
/// let more_ints = ArrayVec::<[i32; 7]>::new();
/// assert_eq!(some_ints, more_ints);
/// ```
///
/// If you have an array and want the _whole thing_ so count as being "in" the
/// new `ArrayVec` you can use one of the `from` implementations. If you want
/// _part of_ the array then you can use
/// [`from_array_len`](ArrayVec::<A>::from_array_len):
/// ```rust
/// # use tinyvec::*;
/// let some_ints = ArrayVec::from([5, 6, 7, 8]);
/// assert_eq!(some_ints.len(), 4);
///
/// let more_ints = ArrayVec::from_array_len([5, 6, 7, 8], 2);
/// assert_eq!(more_ints.len(), 2);
/// ```
#[repr(C)]
#[derive(Clone, Copy, Default)]
pub struct ArrayVec<A: Array> {
@@ -87,7 +130,7 @@ impl<A: Array> ArrayVec<A> {
///
/// ## Example
/// ```rust
/// use tinyvec::*;
/// # use tinyvec::*;
/// let mut av = array_vec!([i32; 10], 1, 2, 3);
/// let mut av2 = array_vec!([i32; 10], 4, 5, 6);
/// av.append(&mut av2);
@@ -101,7 +144,7 @@ impl<A: Array> ArrayVec<A> {
}
}
/// A mutable pointer to the backing array.
/// A `*mut` pointer to the backing array.
///
/// ## Safety
///
@@ -112,14 +155,14 @@ impl<A: Array> ArrayVec<A> {
self.data.as_slice_mut().as_mut_ptr()
}
/// Helper for getting the mut slice.
/// Performs a `deref_mut`, into unique slice form.
#[inline(always)]
#[must_use]
pub fn as_mut_slice(&mut self) -> &mut [A::Item] {
self.deref_mut()
}
/// A const pointer to the backing array.
/// A `*const` pointer to the backing array.
///
/// ## Safety
///
@@ -130,7 +173,7 @@ impl<A: Array> ArrayVec<A> {
self.data.as_slice().as_ptr()
}
/// Helper for getting the shared slice.
/// Performs a `deref`, into shared slice form.
#[inline(always)]
#[must_use]
pub fn as_slice(&self) -> &[A::Item] {
@@ -139,54 +182,20 @@ impl<A: Array> ArrayVec<A> {
/// The capacity of the `ArrayVec`.
///
/// This is fixed based on the array type.
/// This is fixed based on the array type, but can't yet be made a `const fn`
/// on Stable Rust.
#[inline(always)]
#[must_use]
pub fn capacity(&self) -> usize {
A::CAPACITY
}
/// Removes all elements from the vec.
/// Truncates the `ArrayVec` down to length 0.
#[inline(always)]
pub fn clear(&mut self) {
self.truncate(0)
}
/// De-duplicates the vec.
#[cfg(feature = "nightly_slice_partition_dedup")]
#[inline(always)]
pub fn dedup(&mut self)
where
A::Item: PartialEq,
{
self.dedup_by(|a, b| a == b)
}
/// De-duplicates the vec according to the predicate given.
#[cfg(feature = "nightly_slice_partition_dedup")]
#[inline(always)]
pub fn dedup_by<F>(&mut self, same_bucket: F)
where
F: FnMut(&mut A::Item, &mut A::Item) -> bool,
{
let len = {
let (dedup, _) = self.as_mut_slice().partition_dedup_by(same_bucket);
dedup.len()
};
self.truncate(len);
}
/// De-duplicates the vec according to the key selector given.
#[cfg(feature = "nightly_slice_partition_dedup")]
#[inline(always)]
pub fn dedup_by_key<F, K>(&mut self, mut key: F)
where
F: FnMut(&mut A::Item) -> K,
K: PartialEq,
{
self.dedup_by(|a, b| key(a) == key(b))
}
/// Creates a draining iterator that removes the specified range in the vector
/// and yields the removed items.
///
@@ -196,7 +205,7 @@ impl<A: Array> ArrayVec<A> {
///
/// ## Example
/// ```rust
/// use tinyvec::*;
/// # use tinyvec::*;
/// let mut av = array_vec!([i32; 4], 1, 2, 3);
/// let av2: ArrayVec<[i32; 4]> = av.drain(1..).collect();
/// assert_eq!(av.as_slice(), &[1][..]);
@@ -240,9 +249,10 @@ impl<A: Array> ArrayVec<A> {
}
}
// LATER(Vec): drain_filter #nightly https://github.com/rust-lang/rust/issues/43244
/// Clone each element of the slice into this vec.
/// Clone each element of the slice into this `ArrayVec`.
///
/// ## Panics
/// * If the `ArrayVec` would overflow, this will panic.
#[inline]
pub fn extend_from_slice(&mut self, sli: &[A::Item])
where
@@ -255,7 +265,7 @@ impl<A: Array> ArrayVec<A> {
let new_len = self.len + sli.len();
if new_len > A::CAPACITY {
panic!(
"ArrayVec::extend_from_slice: total length {} exceeds capacity {}!",
"ArrayVec::extend_from_slice> total length {} exceeds capacity {}!",
new_len,
A::CAPACITY
)
@@ -268,11 +278,11 @@ impl<A: Array> ArrayVec<A> {
/// Wraps up an array and uses the given length as the initial length.
///
/// Note that the `From` impl for arrays assumes the full length is used.
/// If you want to simply use the full array, use `from` instead.
///
/// ## Panics
///
/// The length must be less than or equal to the capacity of the array.
/// * The length specified must be less than or equal to the capacity of the array.
#[inline]
#[must_use]
#[allow(clippy::match_wild_err_arm)]
@@ -280,7 +290,7 @@ impl<A: Array> ArrayVec<A> {
match Self::try_from_array_len(data, len) {
Ok(out) => out,
Err(_) => {
panic!("ArrayVec: length {} exceeds capacity {}!", len, A::CAPACITY)
panic!("ArrayVec::from_array_len> length {} exceeds capacity {}!", len, A::CAPACITY)
}
}
}
@@ -313,21 +323,21 @@ impl<A: Array> ArrayVec<A> {
self.as_mut_slice()[index..].rotate_right(1);
}
/// If the vec is empty.
/// Checks if the length is 0.
#[inline(always)]
#[must_use]
pub fn is_empty(&self) -> bool {
self.len == 0
}
/// The length of the vec (in elements).
/// The length of the `ArrayVec` (in elements).
#[inline(always)]
#[must_use]
pub fn len(&self) -> usize {
self.len
}
/// Makes a new, empty vec.
/// Makes a new, empty `ArrayVec`.
#[inline(always)]
#[must_use]
pub fn new() -> Self
@@ -341,6 +351,15 @@ impl<A: Array> ArrayVec<A> {
///
/// ## Failure
/// * If the vec is empty you get `None`.
///
/// ## Example
/// ```rust
/// # use tinyvec::*;
/// let mut av = array_vec!([i32; 10], 1, 2);
/// assert_eq!(av.pop(), Some(2));
/// assert_eq!(av.pop(), Some(1));
/// assert_eq!(av.pop(), None);
/// ```
#[inline]
pub fn pop(&mut self) -> Option<A::Item> {
if self.len > 0 {
@@ -356,6 +375,18 @@ impl<A: Array> ArrayVec<A> {
///
/// ## Panics
/// * If the length of the vec would overflow the capacity.
///
/// ## Example
/// ```rust
/// # use tinyvec::*;
/// let mut av = array_vec!([i32; 2]);
/// assert_eq!(&av[..], []);
/// av.push(1);
/// assert_eq!(&av[..], [1]);
/// av.push(2);
/// assert_eq!(&av[..], [1, 2]);
/// // av.push(3); this would overflow the ArrayVec and panic!
/// ```
#[inline(always)]
pub fn push(&mut self, val: A::Item) {
if self.len < A::CAPACITY {
@@ -372,15 +403,15 @@ impl<A: Array> ArrayVec<A> {
///
/// ## Panics
///
/// If the index is out of bounds.
/// * If the index is out of bounds.
///
/// ## Example
///
/// ```rust
/// use tinyvec::*;
/// # use tinyvec::*;
/// let mut av = array_vec!([i32; 4], 1, 2, 3);
/// assert_eq!(av.remove(1), 2);
/// assert_eq!(av.as_slice(), &[1, 3][..]);
/// assert_eq!(&av[..], [1, 3]);
/// ```
#[inline]
pub fn remove(&mut self, index: usize) -> A::Item {
@@ -401,15 +432,15 @@ impl<A: Array> ArrayVec<A> {
/// ## Example
///
/// ```rust
/// use tinyvec::*;
/// # use tinyvec::*;
///
/// let mut av = array_vec!([&str; 10], "hello");
/// av.resize(3, "world");
/// assert_eq!(av.as_slice(), &["hello", "world", "world"][..]);
/// assert_eq!(&av[..], ["hello", "world", "world"]);
///
/// let mut av = array_vec!([i32; 10], 1, 2, 3, 4);
/// av.resize(2, 0);
/// assert_eq!(av.as_slice(), &[1, 2][..]);
/// assert_eq!(&av[..], [1, 2]);
/// ```
#[inline]
pub fn resize(&mut self, new_len: usize, new_val: A::Item)
@@ -436,19 +467,16 @@ impl<A: Array> ArrayVec<A> {
/// ## Example
///
/// ```rust
/// use tinyvec::*;
/// # use tinyvec::*;
///
/// let mut av = array_vec!([i32; 10], 1, 2, 3);
/// av.resize_with(5, Default::default);
/// assert_eq!(av.as_slice(), &[1, 2, 3, 0, 0][..]);
/// assert_eq!(&av[..], [1, 2, 3, 0, 0]);
///
/// let mut av = array_vec!([i32; 10]);
/// let mut p = 1;
/// av.resize_with(4, || {
/// p *= 2;
/// p
/// });
/// assert_eq!(av.as_slice(), &[2, 4, 8, 16][..]);
/// av.resize_with(4, || { p *= 2; p });
/// assert_eq!(&av[..], [2, 4, 8, 16]);
/// ```
#[inline]
pub fn resize_with<F: FnMut() -> A::Item>(
@@ -471,11 +499,11 @@ impl<A: Array> ArrayVec<A> {
/// ## Example
///
/// ```rust
/// use tinyvec::*;
/// # use tinyvec::*;
///
/// let mut av = array_vec!([i32; 10], 1, 1, 2, 3, 3, 4);
/// av.retain(|&x| x % 2 == 0);
/// assert_eq!(av.as_slice(), &[2, 4][..]);
/// assert_eq!(&av[..], [2, 4]);
/// ```
#[inline]
pub fn retain<F: FnMut(&A::Item) -> bool>(&mut self, mut acceptable: F) {
@@ -516,7 +544,7 @@ impl<A: Array> ArrayVec<A> {
/// Forces the length of the vector to `new_len`.
///
/// ## Panics
/// If `new_len` is greater than the vec's capacity.
/// * If `new_len` is greater than the vec's capacity.
///
/// ## Safety
/// * This is a fully safe operation! The inactive memory already counts as
@@ -549,18 +577,18 @@ impl<A: Array> ArrayVec<A> {
/// remaining elements in the iterator and the iterator itself. The
/// interface also provides no way to communicate this to the caller.
///
/// ## Panics
/// * If the `next` method of the provided iterator panics.
///
/// ## Example
///
/// ```rust
/// use tinyvec::*;
/// # use tinyvec::*;
/// let mut av = array_vec!([i32; 4]);
/// let mut to_inf = av.fill(0..);
/// assert_eq!(av.as_slice(), &[0, 1, 2, 3][..]);
/// assert_eq!(&av[..], [0, 1, 2, 3]);
/// assert_eq!(to_inf.next(), Some(4));
/// ```
///
/// ## Panics
/// Only panics if the `next` method of the provided iterator panics.
#[inline]
pub fn fill<I: IntoIterator<Item = A::Item>>(
&mut self,
@@ -584,11 +612,11 @@ impl<A: Array> ArrayVec<A> {
/// ## Example
///
/// ```rust
/// use tinyvec::*;
/// # use tinyvec::*;
/// let mut av = array_vec!([i32; 4], 1, 2, 3);
/// let av2 = av.split_off(1);
/// assert_eq!(av.as_slice(), &[1][..]);
/// assert_eq!(av2.as_slice(), &[2, 3][..]);
/// assert_eq!(&av[..], [1]);
/// assert_eq!(&av2[..], [2, 3]);
/// ```
#[inline]
pub fn split_off(&mut self, at: usize) -> Self
@@ -619,14 +647,14 @@ impl<A: Array> ArrayVec<A> {
///
/// ## Example
/// ```rust
/// use tinyvec::*;
/// # use tinyvec::*;
/// let mut av = array_vec!([&str; 4], "foo", "bar", "quack", "zap");
///
/// assert_eq!(av.swap_remove(1), "bar");
/// assert_eq!(av.as_slice(), &["foo", "zap", "quack"][..]);
/// assert_eq!(&av[..], ["foo", "zap", "quack"]);
///
/// assert_eq!(av.swap_remove(0), "foo");
/// assert_eq!(av.as_slice(), &["quack", "zap"][..]);
/// assert_eq!(&av[..], ["quack", "zap"]);
/// ```
#[inline]
pub fn swap_remove(&mut self, index: usize) -> A::Item {
@@ -675,12 +703,15 @@ impl<A: Array> ArrayVec<A> {
Err(data)
}
}
}
#[cfg(feature = "grab_spare_slice")]
impl<A: Array> ArrayVec<A> {
/// Obtain the shared slice of the array _after_ the active memory.
///
/// ## Example
/// ```rust
/// use tinyvec::*;
/// # use tinyvec::*;
/// let mut av = array_vec!([i32; 4]);
/// assert_eq!(av.grab_spare_slice().len(), 4);
/// av.push(10);
@@ -690,7 +721,6 @@ impl<A: Array> ArrayVec<A> {
/// assert_eq!(av.grab_spare_slice().len(), 0);
/// ```
#[inline(always)]
#[cfg(feature = "grab_spare_slice")]
pub fn grab_spare_slice(&self) -> &[A::Item] {
&self.data.as_slice()[self.len..]
}
@@ -699,7 +729,7 @@ impl<A: Array> ArrayVec<A> {
///
/// ## Example
/// ```rust
/// use tinyvec::*;
/// # use tinyvec::*;
/// let mut av = array_vec!([i32; 4]);
/// assert_eq!(av.grab_spare_slice_mut().len(), 4);
/// av.push(10);
@@ -707,12 +737,46 @@ impl<A: Array> ArrayVec<A> {
/// assert_eq!(av.grab_spare_slice_mut().len(), 2);
/// ```
#[inline(always)]
#[cfg(feature = "grab_spare_slice")]
pub fn grab_spare_slice_mut(&mut self) -> &mut [A::Item] {
&mut self.data.as_slice_mut()[self.len..]
}
}
#[cfg(feature = "nightly_slice_partition_dedup")]
impl<A: Array> ArrayVec<A> {
/// De-duplicates the vec contents.
#[inline(always)]
pub fn dedup(&mut self)
where
A::Item: PartialEq,
{
self.dedup_by(|a, b| a == b)
}
/// De-duplicates the vec according to the predicate given.
#[inline(always)]
pub fn dedup_by<F>(&mut self, same_bucket: F)
where
F: FnMut(&mut A::Item, &mut A::Item) -> bool,
{
let len = {
let (dedup, _) = self.as_mut_slice().partition_dedup_by(same_bucket);
dedup.len()
};
self.truncate(len);
}
/// De-duplicates the vec according to the key selector given.
#[inline(always)]
pub fn dedup_by_key<F, K>(&mut self, mut key: F)
where
F: FnMut(&mut A::Item) -> K,
K: PartialEq,
{
self.dedup_by(|a, b| key(a) == key(b))
}
}
/// Draining iterator for `ArrayVecDrain`
///
/// See [`ArrayVecDrain::drain`](ArrayVecDrain::<A>::drain)
@@ -721,8 +785,6 @@ pub struct ArrayVecDrain<'p, A: Array> {
target_index: usize,
target_count: usize,
}
// GoodFirstIssue: this entire type is correct but slow.
// NIGHTLY: vec_drain_as_slice, https://github.com/rust-lang/rust/issues/58957
impl<'p, A: Array> Iterator for ArrayVecDrain<'p, A> {
type Item = A::Item;
#[inline]
@@ -870,7 +932,7 @@ where
#[inline]
#[must_use]
fn eq(&self, other: &Self) -> bool {
self.deref().eq(other.deref())
self.as_slice().eq(other.as_slice())
}
}
impl<A: Array> Eq for ArrayVec<A> where A::Item: Eq {}
@@ -882,7 +944,7 @@ where
#[inline]
#[must_use]
fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
self.deref().partial_cmp(other.deref())
self.as_slice().partial_cmp(other.as_slice())
}
}
impl<A: Array> Ord for ArrayVec<A>
@@ -892,7 +954,7 @@ where
#[inline]
#[must_use]
fn cmp(&self, other: &Self) -> core::cmp::Ordering {
self.deref().cmp(other.deref())
self.as_slice().cmp(other.as_slice())
}
}
@@ -903,7 +965,7 @@ where
#[inline]
#[must_use]
fn eq(&self, other: &&A) -> bool {
self.deref() == other.as_slice()
self.as_slice().eq(other.as_slice())
}
}
@@ -914,7 +976,7 @@ where
#[inline]
#[must_use]
fn eq(&self, other: &&[A::Item]) -> bool {
self.deref() == *other
self.as_slice().eq(*other)
}
}
@@ -928,9 +990,9 @@ where
}
}
// //
// // // // // // // //
// Formatting impls
// //
// // // // // // // //
impl<A: Array> Binary for ArrayVec<A>
where
+7 -9
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@@ -723,8 +723,6 @@ impl<A: Array> Iterator for TinyVecIterator<A> {
}
}
}
// TODO: fused iterator
impl<A: Array> IntoIterator for TinyVec<A> {
type Item = A::Item;
type IntoIter = TinyVecIterator<A>;
@@ -745,7 +743,7 @@ where
#[inline]
#[must_use]
fn eq(&self, other: &Self) -> bool {
self.deref().eq(other.deref())
self.as_slice().eq(other.as_slice())
}
}
impl<A: Array> Eq for TinyVec<A> where A::Item: Eq {}
@@ -757,7 +755,7 @@ where
#[inline]
#[must_use]
fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
self.deref().partial_cmp(other.deref())
self.as_slice().partial_cmp(other.as_slice())
}
}
impl<A: Array> Ord for TinyVec<A>
@@ -767,7 +765,7 @@ where
#[inline]
#[must_use]
fn cmp(&self, other: &Self) -> core::cmp::Ordering {
self.deref().cmp(other.deref())
self.as_slice().cmp(other.as_slice())
}
}
@@ -778,7 +776,7 @@ where
#[inline]
#[must_use]
fn eq(&self, other: &&A) -> bool {
self.as_slice() == other.as_slice()
self.as_slice().eq(other.as_slice())
}
}
@@ -789,7 +787,7 @@ where
#[inline]
#[must_use]
fn eq(&self, other: &&[A::Item]) -> bool {
self.deref() == *other
self.as_slice().eq(*other)
}
}
@@ -803,9 +801,9 @@ where
}
}
// //
// // // // // // // //
// Formatting impls
// //
// // // // // // // //
impl<A: Array> Binary for TinyVec<A>
where