blob: 50903c51c39b2f69be46710896bfb97ad444a35a [file] [log] [blame]
//! **arrayvec** provides the types `ArrayVec` and `ArrayString`:
//! array-backed vector and string types, which store their contents inline.
//!
//! The arrayvec package has the following cargo features:
//!
//! - `std`
//! - Optional, enabled by default
//! - Use libstd; disable to use `no_std` instead.
//!
//! - `use_union`
//! - Optional
//! - Requires Rust nightly channel
//! - Experimental: This flag uses nightly so it *may break* unexpectedly
//! at some point; since it doesn't change API this flag may also change
//! to do nothing in the future.
//! - Use the unstable feature untagged unions for the internal implementation,
//! which may have reduced space overhead
//! - `serde-1`
//! - Optional
//! - Enable serialization for ArrayVec and ArrayString using serde 1.0
//! - `array-sizes-33-128`, `array-sizes-129-255`
//! - Optional
//! - Enable more array sizes (see [Array] for more information)
//!
//! ## Rust Version
//!
//! This version of arrayvec requires Rust 1.13 or later.
//!
#![doc(html_root_url="https://docs.rs/arrayvec/0.4/")]
#![cfg_attr(not(feature="std"), no_std)]
extern crate nodrop;
#[cfg(feature="serde-1")]
extern crate serde;
#[cfg(not(feature="std"))]
extern crate core as std;
use std::cmp;
use std::iter;
use std::mem;
use std::ptr;
use std::ops::{
Deref,
DerefMut,
};
use std::slice;
// extra traits
use std::borrow::{Borrow, BorrowMut};
use std::hash::{Hash, Hasher};
use std::fmt;
#[cfg(feature="std")]
use std::io;
#[cfg(not(feature="use_union"))]
use nodrop::NoDrop;
#[cfg(feature="use_union")]
use std::mem::ManuallyDrop as NoDrop;
#[cfg(feature="serde-1")]
use serde::{Serialize, Deserialize, Serializer, Deserializer};
mod array;
mod array_string;
mod char;
mod range;
mod errors;
pub use array::Array;
pub use range::RangeArgument;
use array::Index;
pub use array_string::ArrayString;
pub use errors::CapacityError;
unsafe fn new_array<A: Array>() -> A {
// Note: Returning an uninitialized value here only works
// if we can be sure the data is never used. The nullable pointer
// inside enum optimization conflicts with this this for example,
// so we need to be extra careful. See `NoDrop` enum.
mem::uninitialized()
}
/// A vector with a fixed capacity.
///
/// The `ArrayVec` is a vector backed by a fixed size array. It keeps track of
/// the number of initialized elements.
///
/// The vector is a contiguous value that you can store directly on the stack
/// if needed.
///
/// It offers a simple API but also dereferences to a slice, so
/// that the full slice API is available.
///
/// ArrayVec can be converted into a by value iterator.
pub struct ArrayVec<A: Array> {
xs: NoDrop<A>,
len: A::Index,
}
impl<A: Array> Drop for ArrayVec<A> {
fn drop(&mut self) {
self.clear();
// NoDrop inhibits array's drop
// panic safety: NoDrop::drop will trigger on panic, so the inner
// array will not drop even after panic.
}
}
macro_rules! panic_oob {
($method_name:expr, $index:expr, $len:expr) => {
panic!(concat!("ArrayVec::", $method_name, ": index {} is out of bounds in vector of length {}"),
$index, $len)
}
}
impl<A: Array> ArrayVec<A> {
/// Create a new empty `ArrayVec`.
///
/// Capacity is inferred from the type parameter.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::<[_; 16]>::new();
/// array.push(1);
/// array.push(2);
/// assert_eq!(&array[..], &[1, 2]);
/// assert_eq!(array.capacity(), 16);
/// ```
pub fn new() -> ArrayVec<A> {
unsafe {
ArrayVec { xs: NoDrop::new(new_array()), len: Index::from(0) }
}
}
/// Return the number of elements in the `ArrayVec`.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::from([1, 2, 3]);
/// array.pop();
/// assert_eq!(array.len(), 2);
/// ```
#[inline]
pub fn len(&self) -> usize { self.len.to_usize() }
/// Return the capacity of the `ArrayVec`.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let array = ArrayVec::from([1, 2, 3]);
/// assert_eq!(array.capacity(), 3);
/// ```
#[inline]
pub fn capacity(&self) -> usize { A::capacity() }
/// Return if the `ArrayVec` is completely filled.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::<[_; 1]>::new();
/// assert!(!array.is_full());
/// array.push(1);
/// assert!(array.is_full());
/// ```
pub fn is_full(&self) -> bool { self.len() == self.capacity() }
/// Push `element` to the end of the vector.
///
/// ***Panics*** if the vector is already full.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::<[_; 2]>::new();
///
/// array.push(1);
/// array.push(2);
///
/// assert_eq!(&array[..], &[1, 2]);
/// ```
pub fn push(&mut self, element: A::Item) {
self.try_push(element).unwrap()
}
/// Push `element` to the end of the vector.
///
/// Return `Ok` if the push succeeds, or return an error if the vector
/// is already full.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::<[_; 2]>::new();
///
/// let push1 = array.try_push(1);
/// let push2 = array.try_push(2);
///
/// assert!(push1.is_ok());
/// assert!(push2.is_ok());
///
/// assert_eq!(&array[..], &[1, 2]);
///
/// let overflow = array.try_push(3);
///
/// assert!(overflow.is_err());
/// ```
pub fn try_push(&mut self, element: A::Item) -> Result<(), CapacityError<A::Item>> {
if self.len() < A::capacity() {
unsafe {
self.push_unchecked(element);
}
Ok(())
} else {
Err(CapacityError::new(element))
}
}
/// Push `element` to the end of the vector without checking the capacity.
///
/// It is up to the caller to ensure the capacity of the vector is
/// sufficiently large.
///
/// This method uses *debug assertions* to check that the arrayvec is not full.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::<[_; 2]>::new();
///
/// if array.len() + 2 <= array.capacity() {
/// unsafe {
/// array.push_unchecked(1);
/// array.push_unchecked(2);
/// }
/// }
///
/// assert_eq!(&array[..], &[1, 2]);
/// ```
#[inline]
pub unsafe fn push_unchecked(&mut self, element: A::Item) {
let len = self.len();
debug_assert!(len < A::capacity());
ptr::write(self.get_unchecked_mut(len), element);
self.set_len(len + 1);
}
/// Insert `element` at position `index`.
///
/// Shift up all elements after `index`.
///
/// It is an error if the index is greater than the length or if the
/// arrayvec is full.
///
/// ***Panics*** if the array is full or the `index` is out of bounds. See
/// `try_insert` for fallible version.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::<[_; 2]>::new();
///
/// array.insert(0, "x");
/// array.insert(0, "y");
/// assert_eq!(&array[..], &["y", "x"]);
///
/// ```
pub fn insert(&mut self, index: usize, element: A::Item) {
self.try_insert(index, element).unwrap()
}
/// Insert `element` at position `index`.
///
/// Shift up all elements after `index`; the `index` must be less than
/// or equal to the length.
///
/// Returns an error if vector is already at full capacity.
///
/// ***Panics*** `index` is out of bounds.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::<[_; 2]>::new();
///
/// assert!(array.try_insert(0, "x").is_ok());
/// assert!(array.try_insert(0, "y").is_ok());
/// assert!(array.try_insert(0, "z").is_err());
/// assert_eq!(&array[..], &["y", "x"]);
///
/// ```
pub fn try_insert(&mut self, index: usize, element: A::Item) -> Result<(), CapacityError<A::Item>> {
if index > self.len() {
panic_oob!("try_insert", index, self.len())
}
if self.len() == self.capacity() {
return Err(CapacityError::new(element));
}
let len = self.len();
// follows is just like Vec<T>
unsafe { // infallible
// The spot to put the new value
{
let p: *mut _ = self.get_unchecked_mut(index);
// Shift everything over to make space. (Duplicating the
// `index`th element into two consecutive places.)
ptr::copy(p, p.offset(1), len - index);
// Write it in, overwriting the first copy of the `index`th
// element.
ptr::write(p, element);
}
self.set_len(len + 1);
}
Ok(())
}
/// Remove the last element in the vector and return it.
///
/// Return `Some(` *element* `)` if the vector is non-empty, else `None`.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::<[_; 2]>::new();
///
/// array.push(1);
///
/// assert_eq!(array.pop(), Some(1));
/// assert_eq!(array.pop(), None);
/// ```
pub fn pop(&mut self) -> Option<A::Item> {
if self.len() == 0 {
return None
}
unsafe {
let new_len = self.len() - 1;
self.set_len(new_len);
Some(ptr::read(self.get_unchecked_mut(new_len)))
}
}
/// Remove the element at `index` and swap the last element into its place.
///
/// This operation is O(1).
///
/// Return the *element* if the index is in bounds, else panic.
///
/// ***Panics*** if the `index` is out of bounds.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::from([1, 2, 3]);
///
/// assert_eq!(array.swap_remove(0), 1);
/// assert_eq!(&array[..], &[3, 2]);
///
/// assert_eq!(array.swap_remove(1), 2);
/// assert_eq!(&array[..], &[3]);
/// ```
pub fn swap_remove(&mut self, index: usize) -> A::Item {
self.swap_pop(index)
.unwrap_or_else(|| {
panic_oob!("swap_remove", index, self.len())
})
}
/// Remove the element at `index` and swap the last element into its place.
///
/// This is a checked version of `.swap_remove`.
/// This operation is O(1).
///
/// Return `Some(` *element* `)` if the index is in bounds, else `None`.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::from([1, 2, 3]);
///
/// assert_eq!(array.swap_pop(0), Some(1));
/// assert_eq!(&array[..], &[3, 2]);
///
/// assert_eq!(array.swap_pop(10), None);
/// ```
pub fn swap_pop(&mut self, index: usize) -> Option<A::Item> {
let len = self.len();
if index >= len {
return None;
}
self.swap(index, len - 1);
self.pop()
}
/// Remove the element at `index` and shift down the following elements.
///
/// The `index` must be strictly less than the length of the vector.
///
/// ***Panics*** if the `index` is out of bounds.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::from([1, 2, 3]);
///
/// let removed_elt = array.remove(0);
/// assert_eq!(removed_elt, 1);
/// assert_eq!(&array[..], &[2, 3]);
/// ```
pub fn remove(&mut self, index: usize) -> A::Item {
self.pop_at(index)
.unwrap_or_else(|| {
panic_oob!("remove", index, self.len())
})
}
/// Remove the element at `index` and shift down the following elements.
///
/// This is a checked version of `.remove(index)`. Returns `None` if there
/// is no element at `index`. Otherwise, return the element inside `Some`.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::from([1, 2, 3]);
///
/// assert!(array.pop_at(0).is_some());
/// assert_eq!(&array[..], &[2, 3]);
///
/// assert!(array.pop_at(2).is_none());
/// assert!(array.pop_at(10).is_none());
/// ```
pub fn pop_at(&mut self, index: usize) -> Option<A::Item> {
if index >= self.len() {
None
} else {
self.drain(index..index + 1).next()
}
}
/// Shortens the vector, keeping the first `len` elements and dropping
/// the rest.
///
/// If `len` is greater than the vector’s current length this has no
/// effect.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::from([1, 2, 3, 4, 5]);
/// array.truncate(3);
/// assert_eq!(&array[..], &[1, 2, 3]);
/// array.truncate(4);
/// assert_eq!(&array[..], &[1, 2, 3]);
/// ```
pub fn truncate(&mut self, len: usize) {
while self.len() > len { self.pop(); }
}
/// Remove all elements in the vector.
pub fn clear(&mut self) {
while let Some(_) = self.pop() { }
}
/// Retains only the elements specified by the predicate.
///
/// In other words, remove all elements `e` such that `f(&mut e)` returns false.
/// This method operates in place and preserves the order of the retained
/// elements.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::from([1, 2, 3, 4]);
/// array.retain(|x| *x & 1 != 0 );
/// assert_eq!(&array[..], &[1, 3]);
/// ```
pub fn retain<F>(&mut self, mut f: F)
where F: FnMut(&mut A::Item) -> bool
{
let len = self.len();
let mut del = 0;
{
let v = &mut **self;
for i in 0..len {
if !f(&mut v[i]) {
del += 1;
} else if del > 0 {
v.swap(i - del, i);
}
}
}
if del > 0 {
self.drain(len - del..);
}
}
/// Set the vector’s length without dropping or moving out elements
///
/// This method is `unsafe` because it changes the notion of the
/// number of “valid” elements in the vector. Use with care.
///
/// This method uses *debug assertions* to check that check that `length` is
/// not greater than the capacity.
#[inline]
pub unsafe fn set_len(&mut self, length: usize) {
debug_assert!(length <= self.capacity());
self.len = Index::from(length);
}
/// Create a draining iterator that removes the specified range in the vector
/// and yields the removed items from start to end. The element range is
/// removed even if the iterator is not consumed until the end.
///
/// Note: It is unspecified how many elements are removed from the vector,
/// if the `Drain` value is leaked.
///
/// **Panics** if the starting point is greater than the end point or if
/// the end point is greater than the length of the vector.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut v = ArrayVec::from([1, 2, 3]);
/// let u: ArrayVec<[_; 3]> = v.drain(0..2).collect();
/// assert_eq!(&v[..], &[3]);
/// assert_eq!(&u[..], &[1, 2]);
/// ```
pub fn drain<R: RangeArgument>(&mut self, range: R) -> Drain<A> {
// Memory safety
//
// When the Drain is first created, it shortens the length of
// the source vector to make sure no uninitalized or moved-from elements
// are accessible at all if the Drain's destructor never gets to run.
//
// Drain will ptr::read out the values to remove.
// When finished, remaining tail of the vec is copied back to cover
// the hole, and the vector length is restored to the new length.
//
let len = self.len();
let start = range.start().unwrap_or(0);
let end = range.end().unwrap_or(len);
// bounds check happens here
let range_slice: *const _ = &self[start..end];
unsafe {
// set self.vec length's to start, to be safe in case Drain is leaked
self.set_len(start);
Drain {
tail_start: end,
tail_len: len - end,
iter: (*range_slice).iter(),
vec: self as *mut _,
}
}
}
/// Return the inner fixed size array, if it is full to its capacity.
///
/// Return an `Ok` value with the array if length equals capacity,
/// return an `Err` with self otherwise.
///
/// `Note:` This function may incur unproportionally large overhead
/// to move the array out, its performance is not optimal.
pub fn into_inner(self) -> Result<A, Self> {
if self.len() < self.capacity() {
Err(self)
} else {
unsafe {
let array = ptr::read(&*self.xs);
mem::forget(self);
Ok(array)
}
}
}
/// Dispose of `self` without the overwriting that is needed in Drop.
pub fn dispose(mut self) {
self.clear();
mem::forget(self);
}
/// Return a slice containing all elements of the vector.
pub fn as_slice(&self) -> &[A::Item] {
self
}
/// Return a mutable slice containing all elements of the vector.
pub fn as_mut_slice(&mut self) -> &mut [A::Item] {
self
}
}
impl<A: Array> Deref for ArrayVec<A> {
type Target = [A::Item];
#[inline]
fn deref(&self) -> &[A::Item] {
unsafe {
slice::from_raw_parts(self.xs.as_ptr(), self.len())
}
}
}
impl<A: Array> DerefMut for ArrayVec<A> {
#[inline]
fn deref_mut(&mut self) -> &mut [A::Item] {
let len = self.len();
unsafe {
slice::from_raw_parts_mut(self.xs.as_mut_ptr(), len)
}
}
}
/// Create an `ArrayVec` from an array.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::from([1, 2, 3]);
/// assert_eq!(array.len(), 3);
/// assert_eq!(array.capacity(), 3);
/// ```
impl<A: Array> From<A> for ArrayVec<A> {
fn from(array: A) -> Self {
ArrayVec { xs: NoDrop::new(array), len: Index::from(A::capacity()) }
}
}
/// Iterate the `ArrayVec` with references to each element.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let array = ArrayVec::from([1, 2, 3]);
///
/// for elt in &array {
/// // ...
/// }
/// ```
impl<'a, A: Array> IntoIterator for &'a ArrayVec<A> {
type Item = &'a A::Item;
type IntoIter = slice::Iter<'a, A::Item>;
fn into_iter(self) -> Self::IntoIter { self.iter() }
}
/// Iterate the `ArrayVec` with mutable references to each element.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// let mut array = ArrayVec::from([1, 2, 3]);
///
/// for elt in &mut array {
/// // ...
/// }
/// ```
impl<'a, A: Array> IntoIterator for &'a mut ArrayVec<A> {
type Item = &'a mut A::Item;
type IntoIter = slice::IterMut<'a, A::Item>;
fn into_iter(self) -> Self::IntoIter { self.iter_mut() }
}
/// Iterate the `ArrayVec` with each element by value.
///
/// The vector is consumed by this operation.
///
/// ```
/// use arrayvec::ArrayVec;
///
/// for elt in ArrayVec::from([1, 2, 3]) {
/// // ...
/// }
/// ```
impl<A: Array> IntoIterator for ArrayVec<A> {
type Item = A::Item;
type IntoIter = IntoIter<A>;
fn into_iter(self) -> IntoIter<A> {
IntoIter { index: Index::from(0), v: self, }
}
}
/// By-value iterator for `ArrayVec`.
pub struct IntoIter<A: Array> {
index: A::Index,
v: ArrayVec<A>,
}
impl<A: Array> Iterator for IntoIter<A> {
type Item = A::Item;
#[inline]
fn next(&mut self) -> Option<A::Item> {
if self.index == self.v.len {
None
} else {
unsafe {
let index = self.index.to_usize();
self.index = Index::from(index + 1);
Some(ptr::read(self.v.get_unchecked_mut(index)))
}
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
let len = self.v.len() - self.index.to_usize();
(len, Some(len))
}
}
impl<A: Array> DoubleEndedIterator for IntoIter<A> {
#[inline]
fn next_back(&mut self) -> Option<A::Item> {
if self.index == self.v.len {
None
} else {
unsafe {
let new_len = self.v.len() - 1;
self.v.set_len(new_len);
Some(ptr::read(self.v.get_unchecked_mut(new_len)))
}
}
}
}
impl<A: Array> ExactSizeIterator for IntoIter<A> { }
impl<A: Array> Drop for IntoIter<A> {
fn drop(&mut self) {
// panic safety: Set length to 0 before dropping elements.
let index = self.index.to_usize();
let len = self.v.len();
unsafe {
self.v.set_len(0);
let elements = slice::from_raw_parts_mut(
self.v.get_unchecked_mut(index),
len - index);
ptr::drop_in_place(elements);
}
}
}
impl<A: Array> Clone for IntoIter<A>
where
A::Item: Clone,
{
fn clone(&self) -> IntoIter<A> {
self.v[self.index.to_usize()..]
.iter()
.cloned()
.collect::<ArrayVec<A>>()
.into_iter()
}
}
impl<A: Array> fmt::Debug for IntoIter<A>
where
A::Item: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_list()
.entries(&self.v[self.index.to_usize()..])
.finish()
}
}
/// A draining iterator for `ArrayVec`.
pub struct Drain<'a, A>
where A: Array,
A::Item: 'a,
{
/// Index of tail to preserve
tail_start: usize,
/// Length of tail
tail_len: usize,
/// Current remaining range to remove
iter: slice::Iter<'a, A::Item>,
vec: *mut ArrayVec<A>,
}
unsafe impl<'a, A: Array + Sync> Sync for Drain<'a, A> {}
unsafe impl<'a, A: Array + Send> Send for Drain<'a, A> {}
impl<'a, A: Array> Iterator for Drain<'a, A>
where A::Item: 'a,
{
type Item = A::Item;
#[inline]
fn next(&mut self) -> Option<Self::Item> {
self.iter.next().map(|elt|
unsafe {
ptr::read(elt as *const _)
}
)
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
impl<'a, A: Array> DoubleEndedIterator for Drain<'a, A>
where A::Item: 'a,
{
#[inline]
fn next_back(&mut self) -> Option<Self::Item> {
self.iter.next_back().map(|elt|
unsafe {
ptr::read(elt as *const _)
}
)
}
}
impl<'a, A: Array> ExactSizeIterator for Drain<'a, A> where A::Item: 'a {}
impl<'a, A: Array> Drop for Drain<'a, A>
where A::Item: 'a
{
fn drop(&mut self) {
// len is currently 0 so panicking while dropping will not cause a double drop.
// exhaust self first
while let Some(_) = self.next() { }
if self.tail_len > 0 {
unsafe {
let source_vec = &mut *self.vec;
// memmove back untouched tail, update to new length
let start = source_vec.len();
let tail = self.tail_start;
let src = source_vec.as_ptr().offset(tail as isize);
let dst = source_vec.as_mut_ptr().offset(start as isize);
ptr::copy(src, dst, self.tail_len);
source_vec.set_len(start + self.tail_len);
}
}
}
}
struct ScopeExitGuard<T, Data, F>
where F: FnMut(&Data, &mut T)
{
value: T,
data: Data,
f: F,
}
impl<T, Data, F> Drop for ScopeExitGuard<T, Data, F>
where F: FnMut(&Data, &mut T)
{
fn drop(&mut self) {
(self.f)(&self.data, &mut self.value)
}
}
/// Extend the `ArrayVec` with an iterator.
///
/// Does not extract more items than there is space for. No error
/// occurs if there are more iterator elements.
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();
unsafe {
let len = self.len();
let mut ptr = self.as_mut_ptr().offset(len as isize);
// Keep the length in a separate variable, write it back on scope
// exit. To help the compiler with alias analysis and stuff.
// We update the length to handle panic in the iteration of the
// user's iterator, without dropping any elements on the floor.
let mut guard = ScopeExitGuard {
value: self,
data: len,
f: |&len, self_| {
self_.set_len(len)
}
};
for elt in iter.into_iter().take(take) {
ptr::write(ptr, elt);
ptr = ptr.offset(1);
guard.data += 1;
}
}
}
}
/// 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()
}
fn clone_from(&mut self, rhs: &Self) {
// recursive case for the common prefix
let prefix = cmp::min(self.len(), rhs.len());
self[..prefix].clone_from_slice(&rhs[..prefix]);
if prefix < self.len() {
// rhs was shorter
for _ in 0..self.len() - prefix {
self.pop();
}
} else {
let rhs_elems = rhs[self.len()..].iter().cloned();
self.extend(rhs_elems);
}
}
}
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> PartialEq<[A::Item]> for ArrayVec<A>
where A::Item: PartialEq
{
fn eq(&self, other: &[A::Item]) -> 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) }
}
impl<A: Array> Default for ArrayVec<A> {
/// Return an empty array
fn default() -> ArrayVec<A> {
ArrayVec::new()
}
}
impl<A: Array> PartialOrd for ArrayVec<A> where A::Item: PartialOrd {
#[inline]
fn partial_cmp(&self, other: &ArrayVec<A>) -> Option<cmp::Ordering> {
(**self).partial_cmp(other)
}
#[inline]
fn lt(&self, other: &Self) -> bool {
(**self).lt(other)
}
#[inline]
fn le(&self, other: &Self) -> bool {
(**self).le(other)
}
#[inline]
fn ge(&self, other: &Self) -> bool {
(**self).ge(other)
}
#[inline]
fn gt(&self, other: &Self) -> bool {
(**self).gt(other)
}
}
impl<A: Array> Ord for ArrayVec<A> where A::Item: Ord {
fn cmp(&self, other: &ArrayVec<A>) -> cmp::Ordering {
(**self).cmp(other)
}
}
#[cfg(feature="std")]
/// `Write` appends written data to the end of the vector.
///
/// Requires `features="std"`.
impl<A: Array<Item=u8>> io::Write for ArrayVec<A> {
fn write(&mut self, data: &[u8]) -> io::Result<usize> {
unsafe {
let len = self.len();
let mut tail = slice::from_raw_parts_mut(self.get_unchecked_mut(len),
A::capacity() - len);
let result = tail.write(data);
if let Ok(written) = result {
self.set_len(len + written);
}
result
}
}
fn flush(&mut self) -> io::Result<()> { Ok(()) }
}
#[cfg(feature="serde-1")]
/// Requires crate feature `"serde-1"`
impl<T: Serialize, A: Array<Item=T>> Serialize for ArrayVec<A> {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where S: Serializer
{
serializer.collect_seq(self)
}
}
#[cfg(feature="serde-1")]
/// Requires crate feature `"serde-1"`
impl<'de, T: Deserialize<'de>, A: Array<Item=T>> Deserialize<'de> for ArrayVec<A> {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where D: Deserializer<'de>
{
use serde::de::{Visitor, SeqAccess, Error};
use std::marker::PhantomData;
struct ArrayVecVisitor<'de, T: Deserialize<'de>, A: Array<Item=T>>(PhantomData<(&'de (), T, A)>);
impl<'de, T: Deserialize<'de>, A: Array<Item=T>> Visitor<'de> for ArrayVecVisitor<'de, T, A> {
type Value = ArrayVec<A>;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
write!(formatter, "an array with no more than {} items", A::capacity())
}
fn visit_seq<SA>(self, mut seq: SA) -> Result<Self::Value, SA::Error>
where SA: SeqAccess<'de>,
{
let mut values = ArrayVec::<A>::new();
while let Some(value) = try!(seq.next_element()) {
if let Err(_) = values.try_push(value) {
return Err(SA::Error::invalid_length(A::capacity() + 1, &self));
}
}
Ok(values)
}
}
deserializer.deserialize_seq(ArrayVecVisitor::<T, A>(PhantomData))
}
}