root
619 lines
16 KiB
Rust
619 lines
16 KiB
Rust
extern crate odds;
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extern crate nodrop;
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use nodrop::NoDrop;
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use std::iter;
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use std::mem;
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use std::ptr;
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use std::ops::{
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Deref,
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DerefMut,
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};
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use std::slice;
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// extra traits
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use std::borrow::{Borrow, BorrowMut};
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use std::hash::{Hash, Hasher};
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use std::fmt;
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mod array;
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pub use array::Array;
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pub use odds::IndexRange as RangeArgument;
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use array::Index;
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unsafe fn new_array<A: Array>() -> A {
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// Note: Returning an uninitialized value here only works
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// if we can be sure the data is never used. The nullable pointer
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// inside enum optimization conflicts with this this for example,
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// so we need to be extra careful. See `Flag` enum.
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mem::uninitialized()
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}
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/// A vector with a fixed capacity.
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///
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/// The **ArrayVec** is a vector backed by a fixed size array. It keeps track of
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/// the number of initialized elements.
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///
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/// The vector is a contiguous value that you can store directly on the stack
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/// if needed.
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///
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/// It offers a simple API but also dereferences to a slice, so
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/// that the full slice API is available.
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///
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/// ArrayVec can be converted into a by value iterator.
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pub struct ArrayVec<A: Array> {
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xs: NoDrop<A>,
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len: A::Index,
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}
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impl<A: Array> Drop for ArrayVec<A> {
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fn drop(&mut self) {
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// clear all elements, then NoDrop inhibits drop of inner array
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while let Some(_) = self.pop() { }
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}
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}
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impl<A: Array> ArrayVec<A> {
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/// Create a new empty **ArrayVec**.
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///
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/// Capacity is inferred from the type parameter.
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///
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/// ## Examples
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///
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// let mut array = ArrayVec::<[_; 16]>::new();
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/// array.push(1);
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/// array.push(2);
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/// assert_eq!(&array[..], &[1, 2]);
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/// assert_eq!(array.capacity(), 16);
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/// ```
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pub fn new() -> ArrayVec<A> {
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unsafe {
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ArrayVec { xs: NoDrop::new(new_array()), len: Index::zero() }
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}
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}
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/// Return the number of elements in the **ArrayVec**.
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///
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/// ## Examples
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// let mut array = ArrayVec::from([1, 2, 3]);
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/// array.pop();
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/// assert_eq!(array.len(), 2);
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/// ```
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#[inline]
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pub fn len(&self) -> usize { self.len.to_usize() }
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unsafe fn set_len(&mut self, length: usize) {
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debug_assert!(length <= self.capacity());
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self.len = Index::from(length);
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}
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/// Return the capacity of the **ArrayVec**.
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///
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/// ## Examples
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// let array = ArrayVec::from([1, 2, 3]);
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/// assert_eq!(array.capacity(), 3);
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/// ```
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#[inline]
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pub fn capacity(&self) -> usize { A::capacity() }
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/// Push **element** to the end of the vector.
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///
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/// Return **None** if the push succeeds, or and return **Some(** *element* **)**
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/// if the vector is full.
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///
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/// ## Examples
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// let mut array = ArrayVec::<[_; 2]>::new();
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///
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/// array.push(1);
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/// array.push(2);
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/// let overflow = array.push(3);
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///
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/// assert_eq!(&array[..], &[1, 2]);
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/// assert_eq!(overflow, Some(3));
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/// ```
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pub fn push(&mut self, element: A::Item) -> Option<A::Item> {
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if self.len() < A::capacity() {
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let len = self.len();
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unsafe {
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ptr::write(self.get_unchecked_mut(len), element);
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self.set_len(len + 1);
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}
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None
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} else {
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Some(element)
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}
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}
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/// Remove the last element in the vector.
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///
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/// Return **Some(** *element* **)** if the vector is non-empty, else **None**.
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///
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/// ## Examples
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// let mut array = ArrayVec::<[_; 2]>::new();
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///
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/// array.push(1);
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///
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/// assert_eq!(array.pop(), Some(1));
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/// assert_eq!(array.pop(), None);
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/// ```
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pub fn pop(&mut self) -> Option<A::Item> {
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if self.len() == 0 {
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return None
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}
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unsafe {
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let new_len = self.len() - 1;
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self.set_len(new_len);
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Some(ptr::read(self.get_unchecked_mut(new_len)))
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}
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}
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/// Insert **element** in position **index**.
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///
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/// Shift up all elements after **index**. If any is pushed out, it is returned.
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///
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/// Return None if no element is shifted out.
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///
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/// ## Examples
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// let mut array = ArrayVec::<[_; 2]>::new();
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///
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/// assert_eq!(array.insert(0, "x"), None);
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/// assert_eq!(array.insert(0, "y"), None);
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/// assert_eq!(array.insert(0, "z"), Some("x"));
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/// assert_eq!(array.insert(1, "w"), Some("y"));
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/// assert_eq!(&array[..], &["z", "w"]);
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///
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/// ```
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pub fn insert(&mut self, index: usize, element: A::Item) -> Option<A::Item> {
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if index >= self.capacity() {
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return Some(element);
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}
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let mut ret = None;
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let old_len = self.len();
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if old_len == self.capacity() {
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ret = self.pop();
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}
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let len = self.len();
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// follows is just like Vec<T>
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unsafe { // infallible
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// The spot to put the new value
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{
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let p = self.as_mut_ptr().offset(index as isize);
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// Shift everything over to make space. (Duplicating the
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// `index`th element into two consecutive places.)
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ptr::copy(&*p, p.offset(1), len - index);
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// Write it in, overwriting the first copy of the `index`th
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// element.
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ptr::write(&mut *p, element);
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}
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self.set_len(len + 1);
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}
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ret
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}
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/// Remove the element at **index** and swap the last element into its place.
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///
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/// This operation is O(1).
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///
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/// Return **Some(** *element* **)** if the index is in bounds, else **None**.
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///
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/// ## Examples
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// let mut array = ArrayVec::from([1, 2, 3]);
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///
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/// assert_eq!(array.swap_remove(0), Some(1));
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/// assert_eq!(&array[..], &[3, 2]);
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///
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/// assert_eq!(array.swap_remove(10), None);
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/// ```
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pub fn swap_remove(&mut self, index: usize) -> Option<A::Item> {
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let len = self.len();
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if index >= len {
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return None
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}
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self.swap(index, len - 1);
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self.pop()
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}
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/// Remove the element at **index** and shift down the following elements.
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///
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/// Return **Some(** *element* **)** if the index is in bounds, else **None**.
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///
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/// ## Examples
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// let mut array = ArrayVec::from([1, 2, 3]);
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///
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/// assert_eq!(array.remove(0), Some(1));
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/// assert_eq!(&array[..], &[2, 3]);
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///
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/// assert_eq!(array.remove(10), None);
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/// ```
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pub fn remove(&mut self, index: usize) -> Option<A::Item> {
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if index >= self.len() {
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None
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} else {
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self.drain(index..index + 1).next()
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}
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}
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/// Remove all elements in the vector.
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pub fn clear(&mut self) {
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while let Some(_) = self.pop() { }
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}
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/// Create a draining iterator that removes the specified range in the vector
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/// and yields the removed items from start to end. The element range is
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/// removed even if the iterator is not consumed until the end.
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///
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/// Note: It is unspecified how many elements are removed from the vector,
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/// if the `Drain` value is leaked.
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///
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/// # Panics
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///
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/// Panics if the starting point is greater than the end point or if
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/// the end point is greater than the length of the vector.
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///
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/// # Examples
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///
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// let mut v = ArrayVec::from([1, 2, 3]);
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/// let u: Vec<_> = v.drain(0..2).collect();
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/// assert_eq!(&v[..], &[3]);
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/// assert_eq!(&u[..], &[1, 2]);
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/// ```
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pub fn drain<R: RangeArgument>(&mut self, range: R) -> Drain<A> {
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// Memory safety
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//
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// When the Drain is first created, it shortens the length of
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// the source vector to make sure no uninitalized or moved-from elements
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// are accessible at all if the Drain's destructor never gets to run.
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//
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// Drain will ptr::read out the values to remove.
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// When finished, remaining tail of the vec is copied back to cover
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// the hole, and the vector length is restored to the new length.
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//
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let len = self.len();
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let start = range.start().unwrap_or(0);
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let end = range.end().unwrap_or(len);
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// bounds check happens here
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let range_slice: *const _ = &self[start..end];
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unsafe {
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// set self.vec length's to start, to be safe in case Drain is leaked
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self.set_len(start);
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Drain {
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tail_start: end,
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tail_len: len - end,
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iter: (*range_slice).iter(),
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vec: self as *mut _,
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}
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}
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}
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}
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impl<A: Array> Deref for ArrayVec<A> {
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type Target = [A::Item];
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#[inline]
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fn deref(&self) -> &[A::Item] {
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unsafe {
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slice::from_raw_parts(self.xs.as_ptr(), self.len())
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}
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}
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}
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impl<A: Array> DerefMut for ArrayVec<A> {
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#[inline]
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fn deref_mut(&mut self) -> &mut [A::Item] {
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let len = self.len();
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unsafe {
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slice::from_raw_parts_mut(self.xs.as_mut_ptr(), len)
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}
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}
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}
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/// Create an **ArrayVec** from an array.
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///
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/// ## Examples
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// let mut array = ArrayVec::from([1, 2, 3]);
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/// assert_eq!(array.len(), 3);
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/// assert_eq!(array.capacity(), 3);
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/// ```
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impl<A: Array> From<A> for ArrayVec<A> {
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fn from(array: A) -> Self {
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ArrayVec { xs: NoDrop::new(array), len: Index::from(A::capacity()) }
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}
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}
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/// Iterate the **ArrayVec** with references to each element.
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///
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/// ## Examples
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///
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// let array = ArrayVec::from([1, 2, 3]);
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///
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/// for elt in &array {
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/// // ...
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/// }
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/// ```
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impl<'a, A: Array> IntoIterator for &'a ArrayVec<A> {
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type Item = &'a A::Item;
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type IntoIter = slice::Iter<'a, A::Item>;
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fn into_iter(self) -> Self::IntoIter { self.iter() }
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}
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/// Iterate the **ArrayVec** with mutable references to each element.
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///
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/// ## Examples
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///
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// let mut array = ArrayVec::from([1, 2, 3]);
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///
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/// for elt in &mut array {
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/// // ...
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/// }
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/// ```
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impl<'a, A: Array> IntoIterator for &'a mut ArrayVec<A> {
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type Item = &'a mut A::Item;
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type IntoIter = slice::IterMut<'a, A::Item>;
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fn into_iter(self) -> Self::IntoIter { self.iter_mut() }
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}
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/// Iterate the **ArrayVec** with each element by value.
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///
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/// The vector is consumed by this operation.
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///
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/// ## Examples
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///
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/// ```
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/// use arrayvec::ArrayVec;
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///
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/// for elt in ArrayVec::from([1, 2, 3]) {
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/// // ...
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/// }
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/// ```
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impl<A: Array> IntoIterator for ArrayVec<A> {
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type Item = A::Item;
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type IntoIter = IntoIter<A>;
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fn into_iter(self) -> IntoIter<A> {
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IntoIter { index: Index::zero(), v: self, }
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}
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}
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/// By-value iterator for **ArrayVec**.
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pub struct IntoIter<A: Array> {
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index: A::Index,
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v: ArrayVec<A>,
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}
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impl<A: Array> Iterator for IntoIter<A> {
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type Item = A::Item;
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#[inline]
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fn next(&mut self) -> Option<A::Item> {
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if self.index == self.v.len {
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None
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} else {
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unsafe {
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let index = self.index.to_usize();
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self.index = Index::from(index + 1);
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Some(ptr::read(self.v.get_unchecked_mut(index)))
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}
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}
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}
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fn size_hint(&self) -> (usize, Option<usize>) {
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let len = self.v.len() - self.index.to_usize();
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(len, Some(len))
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}
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}
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impl<A: Array> DoubleEndedIterator for IntoIter<A> {
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#[inline]
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fn next_back(&mut self) -> Option<A::Item> {
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if self.index == self.v.len {
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None
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} else {
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unsafe {
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let new_len = self.v.len() - 1;
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self.v.set_len(new_len);
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Some(ptr::read(self.v.get_unchecked_mut(new_len)))
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}
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}
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}
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}
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impl<A: Array> ExactSizeIterator for IntoIter<A> { }
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impl<A: Array> Drop for IntoIter<A> {
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fn drop(&mut self) {
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// exhaust iterator and clear the vector
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while let Some(_) = self.next() { }
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unsafe {
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self.v.set_len(0);
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}
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}
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}
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/// A draining iterator for **ArrayVec**.
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pub struct Drain<'a, A>
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where A: Array,
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A::Item: 'a,
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{
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/// Index of tail to preserve
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tail_start: usize,
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/// Length of tail
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tail_len: usize,
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/// Current remaining range to remove
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iter: slice::Iter<'a, A::Item>,
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vec: *mut ArrayVec<A>,
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}
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unsafe impl<'a, A: Array + Sync> Sync for Drain<'a, A> {}
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unsafe impl<'a, A: Array + Send> Send for Drain<'a, A> {}
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impl<'a, A: Array> Iterator for Drain<'a, A>
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where A::Item: 'a,
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{
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type Item = A::Item;
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#[inline]
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fn next(&mut self) -> Option<Self::Item> {
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self.iter.next().map(|elt|
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unsafe {
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ptr::read(elt as *const _)
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}
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)
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}
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#[inline]
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fn size_hint(&self) -> (usize, Option<usize>) {
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self.iter.size_hint()
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}
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}
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impl<'a, A: Array> DoubleEndedIterator for Drain<'a, A>
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where A::Item: 'a,
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{
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#[inline]
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fn next_back(&mut self) -> Option<Self::Item> {
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self.iter.next_back().map(|elt|
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unsafe {
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ptr::read(elt as *const _)
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}
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)
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}
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}
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impl<'a, A: Array> ExactSizeIterator for Drain<'a, A> where A::Item: 'a {}
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impl<'a, A: Array> Drop for Drain<'a, A>
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where A::Item: 'a
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{
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fn drop(&mut self) {
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// exhaust self first
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while let Some(_) = self.next() { }
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if self.tail_len > 0 {
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unsafe {
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let source_vec = &mut *self.vec;
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// memmove back untouched tail, update to new length
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let start = source_vec.len();
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let tail = self.tail_start;
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let src = source_vec.as_ptr().offset(tail as isize);
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let dst = source_vec.as_mut_ptr().offset(start as isize);
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ptr::copy(src, dst, self.tail_len);
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source_vec.set_len(start + self.tail_len);
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}
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}
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}
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}
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/// Extend the **ArrayVec** with an iterator.
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///
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/// Does not extract more items than there is space for. No error
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/// occurs if there are more iterator elements.
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impl<A: Array> Extend<A::Item> for ArrayVec<A> {
|
|
fn extend<T: IntoIterator<Item=A::Item>>(&mut self, iter: T) {
|
|
let take = self.capacity() - self.len();
|
|
for elt in iter.into_iter().take(take) {
|
|
self.push(elt);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Create an **ArrayVec** from an iterator.
|
|
///
|
|
/// Does not extract more items than there is space for. No error
|
|
/// occurs if there are more iterator elements.
|
|
impl<A: Array> iter::FromIterator<A::Item> for ArrayVec<A> {
|
|
fn from_iter<T: IntoIterator<Item=A::Item>>(iter: T) -> Self {
|
|
let mut array = ArrayVec::new();
|
|
array.extend(iter);
|
|
array
|
|
}
|
|
}
|
|
|
|
impl<A: Array> Clone for ArrayVec<A>
|
|
where A::Item: Clone
|
|
{
|
|
fn clone(&self) -> Self {
|
|
self.iter().cloned().collect()
|
|
}
|
|
}
|
|
|
|
impl<A: Array> Hash for ArrayVec<A>
|
|
where A::Item: Hash
|
|
{
|
|
fn hash<H: Hasher>(&self, state: &mut H) {
|
|
Hash::hash(&**self, state)
|
|
}
|
|
}
|
|
|
|
impl<A: Array> PartialEq for ArrayVec<A>
|
|
where A::Item: PartialEq
|
|
{
|
|
fn eq(&self, other: &Self) -> bool {
|
|
**self == **other
|
|
}
|
|
}
|
|
|
|
impl<A: Array> Eq for ArrayVec<A> where A::Item: Eq { }
|
|
|
|
impl<A: Array> Borrow<[A::Item]> for ArrayVec<A> {
|
|
fn borrow(&self) -> &[A::Item] { self }
|
|
}
|
|
|
|
impl<A: Array> BorrowMut<[A::Item]> for ArrayVec<A> {
|
|
fn borrow_mut(&mut self) -> &mut [A::Item] { self }
|
|
}
|
|
|
|
impl<A: Array> AsRef<[A::Item]> for ArrayVec<A> {
|
|
fn as_ref(&self) -> &[A::Item] { self }
|
|
}
|
|
|
|
impl<A: Array> AsMut<[A::Item]> for ArrayVec<A> {
|
|
fn as_mut(&mut self) -> &mut [A::Item] { self }
|
|
}
|
|
|
|
impl<A: Array> fmt::Debug for ArrayVec<A> where A::Item: fmt::Debug {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { (**self).fmt(f) }
|
|
}
|