rust/src/libcollections/vec.rs
2014-11-16 10:21:33 +01:00

2580 lines
74 KiB
Rust

// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! A growable list type, written `Vec<T>` but pronounced 'vector.'
//!
//! Vectors have `O(1)` indexing, push (to the end) and pop (from the end).
use core::prelude::*;
use alloc::boxed::Box;
use alloc::heap::{EMPTY, allocate, reallocate, deallocate};
use core::cmp::max;
use core::default::Default;
use core::fmt;
use core::kinds::marker::{ContravariantLifetime, InvariantType};
use core::mem;
use core::num::{Int, UnsignedInt};
use core::ops;
use core::ptr;
use core::raw::Slice as RawSlice;
use core::uint;
use slice::{CloneSliceAllocPrelude};
/// An owned, growable vector.
///
/// # Examples
///
/// ```
/// let mut vec = Vec::new();
/// vec.push(1i);
/// vec.push(2i);
///
/// assert_eq!(vec.len(), 2);
/// assert_eq!(vec[0], 1);
///
/// assert_eq!(vec.pop(), Some(2));
/// assert_eq!(vec.len(), 1);
///
/// vec[0] = 7i;
/// assert_eq!(vec[0], 7);
///
/// vec.push_all([1, 2, 3]);
///
/// for x in vec.iter() {
/// println!("{}", x);
/// }
/// assert_eq!(vec, vec![7i, 1, 2, 3]);
/// ```
///
/// The `vec!` macro is provided to make initialization more convenient:
///
/// ```
/// let mut vec = vec![1i, 2i, 3i];
/// vec.push(4);
/// assert_eq!(vec, vec![1, 2, 3, 4]);
/// ```
///
/// Use a `Vec` as an efficient stack:
///
/// ```
/// let mut stack = Vec::new();
///
/// stack.push(1i);
/// stack.push(2i);
/// stack.push(3i);
///
/// loop {
/// let top = match stack.pop() {
/// None => break, // empty
/// Some(x) => x,
/// };
/// // Prints 3, 2, 1
/// println!("{}", top);
/// }
/// ```
///
/// # Capacity and reallocation
///
/// The capacity of a vector is the amount of space allocated for any future
/// elements that will be added onto the vector. This is not to be confused
/// with the *length* of a vector, which specifies the number of actual
/// elements within the vector. If a vector's length exceeds its capacity,
/// its capacity will automatically be increased, but its elements will
/// have to be reallocated.
///
/// For example, a vector with capacity 10 and length 0 would be an empty
/// vector with space for 10 more elements. Pushing 10 or fewer elements onto
/// the vector will not change its capacity or cause reallocation to occur.
/// However, if the vector's length is increased to 11, it will have to
/// reallocate, which can be slow. For this reason, it is recommended
/// to use `Vec::with_capacity` whenever possible to specify how big the vector
/// is expected to get.
#[unsafe_no_drop_flag]
#[stable]
pub struct Vec<T> {
ptr: *mut T,
len: uint,
cap: uint,
}
impl<T> Vec<T> {
/// Constructs a new, empty `Vec`.
///
/// The vector will not allocate until elements are pushed onto it.
///
/// # Example
///
/// ```
/// let mut vec: Vec<int> = Vec::new();
/// ```
#[inline]
#[stable]
pub fn new() -> Vec<T> {
// We want ptr to never be NULL so instead we set it to some arbitrary
// non-null value which is fine since we never call deallocate on the ptr
// if cap is 0. The reason for this is because the pointer of a slice
// being NULL would break the null pointer optimization for enums.
Vec { ptr: EMPTY as *mut T, len: 0, cap: 0 }
}
/// Constructs a new, empty `Vec` with the specified capacity.
///
/// The vector will be able to hold exactly `capacity` elements without
/// reallocating. If `capacity` is 0, the vector will not allocate.
///
/// It is important to note that this function does not specify the
/// *length* of the returned vector, but only the *capacity*. (For an
/// explanation of the difference between length and capacity, see
/// the main `Vec` docs above, 'Capacity and reallocation'.) To create
/// a vector of a given length, use `Vec::from_elem` or `Vec::from_fn`.
///
/// # Example
///
/// ```
/// let mut vec: Vec<int> = Vec::with_capacity(10);
///
/// // The vector contains no items, even though it has capacity for more
/// assert_eq!(vec.len(), 0);
///
/// // These are all done without reallocating...
/// for i in range(0i, 10) {
/// vec.push(i);
/// }
///
/// // ...but this may make the vector reallocate
/// vec.push(11);
/// ```
#[inline]
#[stable]
pub fn with_capacity(capacity: uint) -> Vec<T> {
if mem::size_of::<T>() == 0 {
Vec { ptr: EMPTY as *mut T, len: 0, cap: uint::MAX }
} else if capacity == 0 {
Vec::new()
} else {
let size = capacity.checked_mul(mem::size_of::<T>())
.expect("capacity overflow");
let ptr = unsafe { allocate(size, mem::min_align_of::<T>()) };
Vec { ptr: ptr as *mut T, len: 0, cap: capacity }
}
}
/// Creates and initializes a `Vec`.
///
/// Creates a `Vec` of size `length` and initializes the elements to the
/// value returned by the closure `op`.
///
/// # Example
///
/// ```
/// let vec = Vec::from_fn(3, |idx| idx * 2);
/// assert_eq!(vec, vec![0, 2, 4]);
/// ```
#[inline]
#[unstable = "the naming is uncertain as well as this migrating to unboxed \
closures in the future"]
pub fn from_fn(length: uint, op: |uint| -> T) -> Vec<T> {
unsafe {
let mut xs = Vec::with_capacity(length);
while xs.len < length {
let len = xs.len;
ptr::write(xs.as_mut_slice().unsafe_mut(len), op(len));
xs.len += 1;
}
xs
}
}
/// Creates a `Vec<T>` directly from the raw constituents.
///
/// This is highly unsafe:
///
/// - if `ptr` is null, then `length` and `capacity` should be 0
/// - `ptr` must point to an allocation of size `capacity`
/// - there must be `length` valid instances of type `T` at the
/// beginning of that allocation
/// - `ptr` must be allocated by the default `Vec` allocator
///
/// # Example
///
/// ```
/// use std::ptr;
/// use std::mem;
///
/// fn main() {
/// let mut v = vec![1i, 2, 3];
///
/// // Pull out the various important pieces of information about `v`
/// let p = v.as_mut_ptr();
/// let len = v.len();
/// let cap = v.capacity();
///
/// unsafe {
/// // Cast `v` into the void: no destructor run, so we are in
/// // complete control of the allocation to which `p` points.
/// mem::forget(v);
///
/// // Overwrite memory with 4, 5, 6
/// for i in range(0, len as int) {
/// ptr::write(p.offset(i), 4 + i);
/// }
///
/// // Put everything back together into a Vec
/// let rebuilt = Vec::from_raw_parts(p, len, cap);
/// assert_eq!(rebuilt, vec![4i, 5i, 6i]);
/// }
/// }
/// ```
#[experimental]
pub unsafe fn from_raw_parts(ptr: *mut T, length: uint,
capacity: uint) -> Vec<T> {
Vec { ptr: ptr, len: length, cap: capacity }
}
/// Consumes the `Vec`, partitioning it based on a predicate.
///
/// Partitions the `Vec` into two `Vec`s `(A,B)`, where all elements of `A`
/// satisfy `f` and all elements of `B` do not. The order of elements is
/// preserved.
///
/// # Example
///
/// ```
/// let vec = vec![1i, 2i, 3i, 4i];
/// let (even, odd) = vec.partition(|&n| n % 2 == 0);
/// assert_eq!(even, vec![2, 4]);
/// assert_eq!(odd, vec![1, 3]);
/// ```
#[inline]
#[experimental]
pub fn partition(self, f: |&T| -> bool) -> (Vec<T>, Vec<T>) {
let mut lefts = Vec::new();
let mut rights = Vec::new();
for elt in self.into_iter() {
if f(&elt) {
lefts.push(elt);
} else {
rights.push(elt);
}
}
(lefts, rights)
}
}
impl<T: Clone> Vec<T> {
/// Constructs a `Vec` with copies of a value.
///
/// Creates a `Vec` with `length` copies of `value`.
///
/// # Example
/// ```
/// let vec = Vec::from_elem(3, "hi");
/// println!("{}", vec); // prints [hi, hi, hi]
/// ```
#[inline]
#[unstable = "this functionality may become more generic over all collections"]
pub fn from_elem(length: uint, value: T) -> Vec<T> {
unsafe {
let mut xs = Vec::with_capacity(length);
while xs.len < length {
let len = xs.len;
ptr::write(xs.as_mut_slice().unsafe_mut(len),
value.clone());
xs.len += 1;
}
xs
}
}
/// Appends all elements in a slice to the `Vec`.
///
/// Iterates over the slice `other`, clones each element, and then appends
/// it to this `Vec`. The `other` vector is traversed in-order.
///
/// # Example
///
/// ```
/// let mut vec = vec![1i];
/// vec.push_all([2i, 3, 4]);
/// assert_eq!(vec, vec![1, 2, 3, 4]);
/// ```
#[inline]
#[experimental]
pub fn push_all(&mut self, other: &[T]) {
self.reserve(other.len());
for i in range(0, other.len()) {
let len = self.len();
// Unsafe code so this can be optimised to a memcpy (or something similarly
// fast) when T is Copy. LLVM is easily confused, so any extra operations
// during the loop can prevent this optimisation.
unsafe {
ptr::write(
self.as_mut_slice().unsafe_mut(len),
other.unsafe_get(i).clone());
self.set_len(len + 1);
}
}
}
/// Grows the `Vec` in-place.
///
/// Adds `n` copies of `value` to the `Vec`.
///
/// # Example
///
/// ```
/// let mut vec = vec!["hello"];
/// vec.grow(2, "world");
/// assert_eq!(vec, vec!["hello", "world", "world"]);
/// ```
#[stable]
pub fn grow(&mut self, n: uint, value: T) {
self.reserve(n);
let mut i: uint = 0u;
while i < n {
self.push(value.clone());
i += 1u;
}
}
/// Partitions a vector based on a predicate.
///
/// Clones the elements of the vector, partitioning them into two `Vec`s
/// `(a, b)`, where all elements of `a` satisfy `f` and all elements of `b`
/// do not. The order of elements is preserved.
///
/// # Example
///
/// ```
/// let vec = vec![1i, 2, 3, 4];
/// let (even, odd) = vec.partitioned(|&n| n % 2 == 0);
/// assert_eq!(even, vec![2i, 4]);
/// assert_eq!(odd, vec![1i, 3]);
/// ```
#[experimental]
pub fn partitioned(&self, f: |&T| -> bool) -> (Vec<T>, Vec<T>) {
let mut lefts = Vec::new();
let mut rights = Vec::new();
for elt in self.iter() {
if f(elt) {
lefts.push(elt.clone());
} else {
rights.push(elt.clone());
}
}
(lefts, rights)
}
}
#[unstable]
impl<T:Clone> Clone for Vec<T> {
fn clone(&self) -> Vec<T> { self.as_slice().to_vec() }
fn clone_from(&mut self, other: &Vec<T>) {
// drop anything in self that will not be overwritten
if self.len() > other.len() {
self.truncate(other.len())
}
// reuse the contained values' allocations/resources.
for (place, thing) in self.iter_mut().zip(other.iter()) {
place.clone_from(thing)
}
// self.len <= other.len due to the truncate above, so the
// slice here is always in-bounds.
let slice = other[self.len()..];
self.push_all(slice);
}
}
#[experimental = "waiting on Index stability"]
impl<T> Index<uint,T> for Vec<T> {
#[inline]
fn index<'a>(&'a self, index: &uint) -> &'a T {
&self.as_slice()[*index]
}
}
impl<T> IndexMut<uint,T> for Vec<T> {
#[inline]
fn index_mut<'a>(&'a mut self, index: &uint) -> &'a mut T {
&mut self.as_mut_slice()[*index]
}
}
impl<T> ops::Slice<uint, [T]> for Vec<T> {
#[inline]
fn as_slice_<'a>(&'a self) -> &'a [T] {
self.as_slice()
}
#[inline]
fn slice_from_or_fail<'a>(&'a self, start: &uint) -> &'a [T] {
self.as_slice().slice_from_or_fail(start)
}
#[inline]
fn slice_to_or_fail<'a>(&'a self, end: &uint) -> &'a [T] {
self.as_slice().slice_to_or_fail(end)
}
#[inline]
fn slice_or_fail<'a>(&'a self, start: &uint, end: &uint) -> &'a [T] {
self.as_slice().slice_or_fail(start, end)
}
}
impl<T> ops::SliceMut<uint, [T]> for Vec<T> {
#[inline]
fn as_mut_slice_<'a>(&'a mut self) -> &'a mut [T] {
self.as_mut_slice()
}
#[inline]
fn slice_from_or_fail_mut<'a>(&'a mut self, start: &uint) -> &'a mut [T] {
self.as_mut_slice().slice_from_or_fail_mut(start)
}
#[inline]
fn slice_to_or_fail_mut<'a>(&'a mut self, end: &uint) -> &'a mut [T] {
self.as_mut_slice().slice_to_or_fail_mut(end)
}
#[inline]
fn slice_or_fail_mut<'a>(&'a mut self, start: &uint, end: &uint) -> &'a mut [T] {
self.as_mut_slice().slice_or_fail_mut(start, end)
}
}
#[experimental = "waiting on Deref stability"]
impl<T> ops::Deref<[T]> for Vec<T> {
fn deref<'a>(&'a self) -> &'a [T] { self.as_slice() }
}
#[experimental = "waiting on DerefMut stability"]
impl<T> ops::DerefMut<[T]> for Vec<T> {
fn deref_mut<'a>(&'a mut self) -> &'a mut [T] { self.as_mut_slice() }
}
#[experimental = "waiting on FromIterator stability"]
impl<T> FromIterator<T> for Vec<T> {
#[inline]
fn from_iter<I:Iterator<T>>(mut iterator: I) -> Vec<T> {
let (lower, _) = iterator.size_hint();
let mut vector = Vec::with_capacity(lower);
for element in iterator {
vector.push(element)
}
vector
}
}
#[experimental = "waiting on Extend stability"]
impl<T> Extend<T> for Vec<T> {
#[inline]
fn extend<I: Iterator<T>>(&mut self, mut iterator: I) {
let (lower, _) = iterator.size_hint();
self.reserve(lower);
for element in iterator {
self.push(element)
}
}
}
#[unstable = "waiting on PartialEq stability"]
impl<T: PartialEq> PartialEq for Vec<T> {
#[inline]
fn eq(&self, other: &Vec<T>) -> bool {
self.as_slice() == other.as_slice()
}
}
#[unstable = "waiting on PartialOrd stability"]
impl<T: PartialOrd> PartialOrd for Vec<T> {
#[inline]
fn partial_cmp(&self, other: &Vec<T>) -> Option<Ordering> {
self.as_slice().partial_cmp(other.as_slice())
}
}
#[unstable = "waiting on Eq stability"]
impl<T: Eq> Eq for Vec<T> {}
#[experimental]
impl<T: PartialEq, V: AsSlice<T>> Equiv<V> for Vec<T> {
#[inline]
fn equiv(&self, other: &V) -> bool { self.as_slice() == other.as_slice() }
}
#[unstable = "waiting on Ord stability"]
impl<T: Ord> Ord for Vec<T> {
#[inline]
fn cmp(&self, other: &Vec<T>) -> Ordering {
self.as_slice().cmp(other.as_slice())
}
}
// FIXME: #13996: need a way to mark the return value as `noalias`
#[inline(never)]
unsafe fn alloc_or_realloc<T>(ptr: *mut T, old_size: uint, size: uint) -> *mut T {
if old_size == 0 {
allocate(size, mem::min_align_of::<T>()) as *mut T
} else {
reallocate(ptr as *mut u8, old_size, size, mem::min_align_of::<T>()) as *mut T
}
}
#[inline]
unsafe fn dealloc<T>(ptr: *mut T, len: uint) {
if mem::size_of::<T>() != 0 {
deallocate(ptr as *mut u8,
len * mem::size_of::<T>(),
mem::min_align_of::<T>())
}
}
impl<T> Vec<T> {
/// Returns the number of elements the vector can hold without
/// reallocating.
///
/// # Example
///
/// ```
/// let vec: Vec<int> = Vec::with_capacity(10);
/// assert_eq!(vec.capacity(), 10);
/// ```
#[inline]
#[stable]
pub fn capacity(&self) -> uint {
self.cap
}
/// Deprecated: Renamed to `reserve`.
#[deprecated = "Renamed to `reserve`"]
pub fn reserve_additional(&mut self, extra: uint) {
self.reserve(extra)
}
/// Reserves capacity for at least `additional` more elements to be inserted in the given
/// `Vec`. The collection may reserve more space to avoid frequent reallocations.
///
/// # Panics
///
/// Panics if the new capacity overflows `uint`.
///
/// # Example
///
/// ```
/// let mut vec: Vec<int> = vec![1];
/// vec.reserve(10);
/// assert!(vec.capacity() >= 11);
/// ```
#[unstable = "matches collection reform specification, waiting for dust to settle"]
pub fn reserve(&mut self, additional: uint) {
if self.cap - self.len < additional {
match self.len.checked_add(additional) {
None => panic!("Vec::reserve: `uint` overflow"),
// if the checked_add
Some(new_cap) => {
let amort_cap = new_cap.next_power_of_two();
// next_power_of_two will overflow to exactly 0 for really big capacities
if amort_cap == 0 {
self.grow_capacity(new_cap);
} else {
self.grow_capacity(amort_cap);
}
}
}
}
}
/// Reserves the minimum capacity for exactly `additional` more elements to be inserted in the
/// given `Vec`. Does nothing if the capacity is already sufficient.
///
/// Note that the allocator may give the collection more space than it requests. Therefore
/// capacity can not be relied upon to be precisely minimal. Prefer `reserve` if future
/// insertions are expected.
///
/// # Panics
///
/// Panics if the new capacity overflows `uint`.
///
/// # Example
///
/// ```
/// let mut vec: Vec<int> = vec![1];
/// vec.reserve_exact(10);
/// assert!(vec.capacity() >= 11);
/// ```
#[unstable = "matches collection reform specification, waiting for dust to settle"]
pub fn reserve_exact(&mut self, additional: uint) {
if self.cap - self.len < additional {
match self.len.checked_add(additional) {
None => panic!("Vec::reserve: `uint` overflow"),
Some(new_cap) => self.grow_capacity(new_cap)
}
}
}
/// Shrinks the capacity of the vector as much as possible. It will drop
/// down as close as possible to the length but the allocator may still
/// inform the vector that there is space for a few more elements.
///
/// # Example
///
/// ```
/// let mut vec: Vec<int> = Vec::with_capacity(10);
/// vec.push_all([1, 2, 3]);
/// assert_eq!(vec.capacity(), 10);
/// vec.shrink_to_fit();
/// assert!(vec.capacity() >= 3);
/// ```
#[stable]
pub fn shrink_to_fit(&mut self) {
if mem::size_of::<T>() == 0 { return }
if self.len == 0 {
if self.cap != 0 {
unsafe {
dealloc(self.ptr, self.cap)
}
self.cap = 0;
}
} else {
unsafe {
// Overflow check is unnecessary as the vector is already at
// least this large.
self.ptr = reallocate(self.ptr as *mut u8,
self.cap * mem::size_of::<T>(),
self.len * mem::size_of::<T>(),
mem::min_align_of::<T>()) as *mut T;
if self.ptr.is_null() { ::alloc::oom() }
}
self.cap = self.len;
}
}
/// Convert the vector into Box<[T]>.
///
/// Note that this will drop any excess capacity. Calling this and converting back to a vector
/// with `into_vec()` is equivalent to calling `shrink_to_fit()`.
#[experimental]
pub fn into_boxed_slice(mut self) -> Box<[T]> {
self.shrink_to_fit();
unsafe {
let xs: Box<[T]> = mem::transmute(self.as_mut_slice());
mem::forget(self);
xs
}
}
/// Shorten a vector, dropping excess elements.
///
/// If `len` is greater than the vector's current length, this has no
/// effect.
///
/// # Example
///
/// ```
/// let mut vec = vec![1i, 2, 3, 4];
/// vec.truncate(2);
/// assert_eq!(vec, vec![1, 2]);
/// ```
#[unstable = "matches collection reform specification; waiting on panic semantics"]
pub fn truncate(&mut self, len: uint) {
unsafe {
// drop any extra elements
while len < self.len {
// decrement len before the read(), so a panic on Drop doesn't
// re-drop the just-failed value.
self.len -= 1;
ptr::read(self.as_slice().unsafe_get(self.len));
}
}
}
/// Returns a mutable slice of the elements of `self`.
///
/// # Example
///
/// ```
/// fn foo(slice: &mut [int]) {}
///
/// let mut vec = vec![1i, 2];
/// foo(vec.as_mut_slice());
/// ```
#[inline]
#[stable]
pub fn as_mut_slice<'a>(&'a mut self) -> &'a mut [T] {
unsafe {
mem::transmute(RawSlice {
data: self.ptr as *const T,
len: self.len,
})
}
}
/// Creates a consuming iterator, that is, one that moves each
/// value out of the vector (from start to end). The vector cannot
/// be used after calling this.
///
/// # Example
///
/// ```
/// let v = vec!["a".to_string(), "b".to_string()];
/// for s in v.into_iter() {
/// // s has type String, not &String
/// println!("{}", s);
/// }
/// ```
#[inline]
#[unstable = "matches collection reform specification, waiting for dust to settle"]
pub fn into_iter(self) -> MoveItems<T> {
unsafe {
let ptr = self.ptr;
let cap = self.cap;
let begin = self.ptr as *const T;
let end = if mem::size_of::<T>() == 0 {
(ptr as uint + self.len()) as *const T
} else {
ptr.offset(self.len() as int) as *const T
};
mem::forget(self);
MoveItems { allocation: ptr, cap: cap, ptr: begin, end: end }
}
}
/// Sets the length of a vector.
///
/// This will explicitly set the size of the vector, without actually
/// modifying its buffers, so it is up to the caller to ensure that the
/// vector is actually the specified size.
///
/// # Example
///
/// ```
/// let mut v = vec![1u, 2, 3, 4];
/// unsafe {
/// v.set_len(1);
/// }
/// ```
#[inline]
#[stable]
pub unsafe fn set_len(&mut self, len: uint) {
self.len = len;
}
/// Removes an element from anywhere in the vector and return it, replacing
/// it with the last element. This does not preserve ordering, but is O(1).
///
/// Returns `None` if `index` is out of bounds.
///
/// # Example
/// ```
/// let mut v = vec!["foo", "bar", "baz", "qux"];
///
/// assert_eq!(v.swap_remove(1), Some("bar"));
/// assert_eq!(v, vec!["foo", "qux", "baz"]);
///
/// assert_eq!(v.swap_remove(0), Some("foo"));
/// assert_eq!(v, vec!["baz", "qux"]);
///
/// assert_eq!(v.swap_remove(2), None);
/// ```
#[inline]
#[unstable = "the naming of this function may be altered"]
pub fn swap_remove(&mut self, index: uint) -> Option<T> {
let length = self.len();
if length > 0 && index < length - 1 {
self.as_mut_slice().swap(index, length - 1);
} else if index >= length {
return None
}
self.pop()
}
/// Inserts an element at position `index` within the vector, shifting all
/// elements after position `i` one position to the right.
///
/// # Panics
///
/// Panics if `index` is not between `0` and the vector's length (both
/// bounds inclusive).
///
/// # Example
///
/// ```
/// let mut vec = vec![1i, 2, 3];
/// vec.insert(1, 4);
/// assert_eq!(vec, vec![1, 4, 2, 3]);
/// vec.insert(4, 5);
/// assert_eq!(vec, vec![1, 4, 2, 3, 5]);
/// ```
#[unstable = "panic semantics need settling"]
pub fn insert(&mut self, index: uint, element: T) {
let len = self.len();
assert!(index <= len);
// space for the new element
self.reserve(1);
unsafe { // infallible
// The spot to put the new value
{
let p = self.as_mut_ptr().offset(index as int);
// Shift everything over to make space. (Duplicating the
// `index`th element into two consecutive places.)
ptr::copy_memory(p.offset(1), &*p, len - index);
// Write it in, overwriting the first copy of the `index`th
// element.
ptr::write(&mut *p, element);
}
self.set_len(len + 1);
}
}
/// Removes and returns the element at position `index` within the vector,
/// shifting all elements after position `index` one position to the left.
/// Returns `None` if `i` is out of bounds.
///
/// # Example
///
/// ```
/// let mut v = vec![1i, 2, 3];
/// assert_eq!(v.remove(1), Some(2));
/// assert_eq!(v, vec![1, 3]);
///
/// assert_eq!(v.remove(4), None);
/// // v is unchanged:
/// assert_eq!(v, vec![1, 3]);
/// ```
#[unstable = "panic semantics need settling"]
pub fn remove(&mut self, index: uint) -> Option<T> {
let len = self.len();
if index < len {
unsafe { // infallible
let ret;
{
// the place we are taking from.
let ptr = self.as_mut_ptr().offset(index as int);
// copy it out, unsafely having a copy of the value on
// the stack and in the vector at the same time.
ret = Some(ptr::read(ptr as *const T));
// Shift everything down to fill in that spot.
ptr::copy_memory(ptr, &*ptr.offset(1), len - index - 1);
}
self.set_len(len - 1);
ret
}
} else {
None
}
}
/// Retains only the elements specified by the predicate.
///
/// In other words, remove all elements `e` such that `f(&e)` returns false.
/// This method operates in place and preserves the order of the retained elements.
///
/// # Example
///
/// ```
/// let mut vec = vec![1i, 2, 3, 4];
/// vec.retain(|&x| x%2 == 0);
/// assert_eq!(vec, vec![2, 4]);
/// ```
#[unstable = "the closure argument may become an unboxed closure"]
pub fn retain(&mut self, f: |&T| -> bool) {
let len = self.len();
let mut del = 0u;
{
let v = self.as_mut_slice();
for i in range(0u, len) {
if !f(&v[i]) {
del += 1;
} else if del > 0 {
v.swap(i-del, i);
}
}
}
if del > 0 {
self.truncate(len - del);
}
}
/// Expands a vector in place, initializing the new elements to the result of a function.
///
/// The vector is grown by `n` elements. The i-th new element are initialized to the value
/// returned by `f(i)` where `i` is in the range [0, n).
///
/// # Example
///
/// ```
/// let mut vec = vec![0u, 1];
/// vec.grow_fn(3, |i| i);
/// assert_eq!(vec, vec![0, 1, 0, 1, 2]);
/// ```
#[unstable = "this function may be renamed or change to unboxed closures"]
pub fn grow_fn(&mut self, n: uint, f: |uint| -> T) {
self.reserve(n);
for i in range(0u, n) {
self.push(f(i));
}
}
/// Appends an element to the back of a collection.
///
/// # Panics
///
/// Panics if the number of elements in the vector overflows a `uint`.
///
/// # Example
///
/// ```rust
/// let mut vec = vec!(1i, 2);
/// vec.push(3);
/// assert_eq!(vec, vec!(1, 2, 3));
/// ```
#[inline]
#[stable]
pub fn push(&mut self, value: T) {
if mem::size_of::<T>() == 0 {
// zero-size types consume no memory, so we can't rely on the address space running out
self.len = self.len.checked_add(1).expect("length overflow");
unsafe { mem::forget(value); }
return
}
if self.len == self.cap {
let old_size = self.cap * mem::size_of::<T>();
let size = max(old_size, 2 * mem::size_of::<T>()) * 2;
if old_size > size { panic!("capacity overflow") }
unsafe {
self.ptr = alloc_or_realloc(self.ptr, old_size, size);
if self.ptr.is_null() { ::alloc::oom() }
}
self.cap = max(self.cap, 2) * 2;
}
unsafe {
let end = (self.ptr as *const T).offset(self.len as int) as *mut T;
ptr::write(&mut *end, value);
self.len += 1;
}
}
/// Removes the last element from a vector and returns it, or `None` if
/// it is empty.
///
/// # Example
///
/// ```rust
/// let mut vec = vec![1i, 2, 3];
/// assert_eq!(vec.pop(), Some(3));
/// assert_eq!(vec, vec![1, 2]);
/// ```
#[inline]
#[stable]
pub fn pop(&mut self) -> Option<T> {
if self.len == 0 {
None
} else {
unsafe {
self.len -= 1;
Some(ptr::read(self.as_slice().unsafe_get(self.len())))
}
}
}
/// Clears the vector, removing all values.
///
/// # Example
///
/// ```
/// let mut v = vec![1i, 2, 3];
/// v.clear();
/// assert!(v.is_empty());
/// ```
#[inline]
#[stable]
pub fn clear(&mut self) {
self.truncate(0)
}
/// Return the number of elements in the vector
///
/// # Example
///
/// ```
/// let a = vec![1i, 2, 3];
/// assert_eq!(a.len(), 3);
/// ```
#[inline]
#[stable]
pub fn len(&self) -> uint { self.len }
/// Returns true if the vector contains no elements
///
/// # Example
///
/// ```
/// let mut v = Vec::new();
/// assert!(v.is_empty());
/// v.push(1i);
/// assert!(!v.is_empty());
/// ```
#[unstable = "matches collection reform specification, waiting for dust to settle"]
pub fn is_empty(&self) -> bool { self.len() == 0 }
/// Reserves capacity for exactly `capacity` elements in the given vector.
///
/// If the capacity for `self` is already equal to or greater than the
/// requested capacity, then no action is taken.
fn grow_capacity(&mut self, capacity: uint) {
if mem::size_of::<T>() == 0 { return }
if capacity > self.cap {
let size = capacity.checked_mul(mem::size_of::<T>())
.expect("capacity overflow");
unsafe {
self.ptr = alloc_or_realloc(self.ptr, self.cap * mem::size_of::<T>(), size);
if self.ptr.is_null() { ::alloc::oom() }
}
self.cap = capacity;
}
}
}
impl<T: PartialEq> Vec<T> {
/// Removes consecutive repeated elements in the vector.
///
/// If the vector is sorted, this removes all duplicates.
///
/// # Example
///
/// ```
/// let mut vec = vec![1i, 2, 2, 3, 2];
/// vec.dedup();
/// assert_eq!(vec, vec![1i, 2, 3, 2]);
/// ```
#[unstable = "this function may be renamed"]
pub fn dedup(&mut self) {
unsafe {
// Although we have a mutable reference to `self`, we cannot make
// *arbitrary* changes. The `PartialEq` comparisons could panic, so we
// must ensure that the vector is in a valid state at all time.
//
// The way that we handle this is by using swaps; we iterate
// over all the elements, swapping as we go so that at the end
// the elements we wish to keep are in the front, and those we
// wish to reject are at the back. We can then truncate the
// vector. This operation is still O(n).
//
// Example: We start in this state, where `r` represents "next
// read" and `w` represents "next_write`.
//
// r
// +---+---+---+---+---+---+
// | 0 | 1 | 1 | 2 | 3 | 3 |
// +---+---+---+---+---+---+
// w
//
// Comparing self[r] against self[w-1], this is not a duplicate, so
// we swap self[r] and self[w] (no effect as r==w) and then increment both
// r and w, leaving us with:
//
// r
// +---+---+---+---+---+---+
// | 0 | 1 | 1 | 2 | 3 | 3 |
// +---+---+---+---+---+---+
// w
//
// Comparing self[r] against self[w-1], this value is a duplicate,
// so we increment `r` but leave everything else unchanged:
//
// r
// +---+---+---+---+---+---+
// | 0 | 1 | 1 | 2 | 3 | 3 |
// +---+---+---+---+---+---+
// w
//
// Comparing self[r] against self[w-1], this is not a duplicate,
// so swap self[r] and self[w] and advance r and w:
//
// r
// +---+---+---+---+---+---+
// | 0 | 1 | 2 | 1 | 3 | 3 |
// +---+---+---+---+---+---+
// w
//
// Not a duplicate, repeat:
//
// r
// +---+---+---+---+---+---+
// | 0 | 1 | 2 | 3 | 1 | 3 |
// +---+---+---+---+---+---+
// w
//
// Duplicate, advance r. End of vec. Truncate to w.
let ln = self.len();
if ln < 1 { return; }
// Avoid bounds checks by using unsafe pointers.
let p = self.as_mut_slice().as_mut_ptr();
let mut r = 1;
let mut w = 1;
while r < ln {
let p_r = p.offset(r as int);
let p_wm1 = p.offset((w - 1) as int);
if *p_r != *p_wm1 {
if r != w {
let p_w = p_wm1.offset(1);
mem::swap(&mut *p_r, &mut *p_w);
}
w += 1;
}
r += 1;
}
self.truncate(w);
}
}
}
impl<T> AsSlice<T> for Vec<T> {
/// Returns a slice into `self`.
///
/// # Example
///
/// ```
/// fn foo(slice: &[int]) {}
///
/// let vec = vec![1i, 2];
/// foo(vec.as_slice());
/// ```
#[inline]
#[stable]
fn as_slice<'a>(&'a self) -> &'a [T] {
unsafe {
mem::transmute(RawSlice {
data: self.ptr as *const T,
len: self.len
})
}
}
}
impl<T: Clone, V: AsSlice<T>> Add<V, Vec<T>> for Vec<T> {
#[inline]
fn add(&self, rhs: &V) -> Vec<T> {
let mut res = Vec::with_capacity(self.len() + rhs.as_slice().len());
res.push_all(self.as_slice());
res.push_all(rhs.as_slice());
res
}
}
#[unsafe_destructor]
impl<T> Drop for Vec<T> {
fn drop(&mut self) {
// This is (and should always remain) a no-op if the fields are
// zeroed (when moving out, because of #[unsafe_no_drop_flag]).
if self.cap != 0 {
unsafe {
for x in self.as_mut_slice().iter() {
ptr::read(x);
}
dealloc(self.ptr, self.cap)
}
}
}
}
#[stable]
impl<T> Default for Vec<T> {
fn default() -> Vec<T> {
Vec::new()
}
}
#[experimental = "waiting on Show stability"]
impl<T:fmt::Show> fmt::Show for Vec<T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
self.as_slice().fmt(f)
}
}
/// An iterator that moves out of a vector.
pub struct MoveItems<T> {
allocation: *mut T, // the block of memory allocated for the vector
cap: uint, // the capacity of the vector
ptr: *const T,
end: *const T
}
impl<T> MoveItems<T> {
#[inline]
/// Drops all items that have not yet been moved and returns the empty vector.
pub fn unwrap(mut self) -> Vec<T> {
unsafe {
for _x in self { }
let MoveItems { allocation, cap, ptr: _ptr, end: _end } = self;
mem::forget(self);
Vec { ptr: allocation, cap: cap, len: 0 }
}
}
}
impl<T> Iterator<T> for MoveItems<T> {
#[inline]
fn next<'a>(&'a mut self) -> Option<T> {
unsafe {
if self.ptr == self.end {
None
} else {
if mem::size_of::<T>() == 0 {
// purposefully don't use 'ptr.offset' because for
// vectors with 0-size elements this would return the
// same pointer.
self.ptr = mem::transmute(self.ptr as uint + 1);
// Use a non-null pointer value
Some(ptr::read(mem::transmute(1u)))
} else {
let old = self.ptr;
self.ptr = self.ptr.offset(1);
Some(ptr::read(old))
}
}
}
}
#[inline]
fn size_hint(&self) -> (uint, Option<uint>) {
let diff = (self.end as uint) - (self.ptr as uint);
let size = mem::size_of::<T>();
let exact = diff / (if size == 0 {1} else {size});
(exact, Some(exact))
}
}
impl<T> DoubleEndedIterator<T> for MoveItems<T> {
#[inline]
fn next_back<'a>(&'a mut self) -> Option<T> {
unsafe {
if self.end == self.ptr {
None
} else {
if mem::size_of::<T>() == 0 {
// See above for why 'ptr.offset' isn't used
self.end = mem::transmute(self.end as uint - 1);
// Use a non-null pointer value
Some(ptr::read(mem::transmute(1u)))
} else {
self.end = self.end.offset(-1);
Some(ptr::read(mem::transmute(self.end)))
}
}
}
}
}
impl<T> ExactSize<T> for MoveItems<T> {}
#[unsafe_destructor]
impl<T> Drop for MoveItems<T> {
fn drop(&mut self) {
// destroy the remaining elements
if self.cap != 0 {
for _x in *self {}
unsafe {
dealloc(self.allocation, self.cap);
}
}
}
}
/// Converts an iterator of pairs into a pair of vectors.
///
/// Returns a tuple containing two vectors where the i-th element of the first
/// vector contains the first element of the i-th tuple of the input iterator,
/// and the i-th element of the second vector contains the second element
/// of the i-th tuple of the input iterator.
#[unstable = "this functionality may become more generic over time"]
pub fn unzip<T, U, V: Iterator<(T, U)>>(mut iter: V) -> (Vec<T>, Vec<U>) {
let (lo, _) = iter.size_hint();
let mut ts = Vec::with_capacity(lo);
let mut us = Vec::with_capacity(lo);
for (t, u) in iter {
ts.push(t);
us.push(u);
}
(ts, us)
}
/// Wrapper type providing a `&Vec<T>` reference via `Deref`.
#[experimental]
pub struct DerefVec<'a, T> {
x: Vec<T>,
l: ContravariantLifetime<'a>
}
impl<'a, T> Deref<Vec<T>> for DerefVec<'a, T> {
fn deref<'b>(&'b self) -> &'b Vec<T> {
&self.x
}
}
// Prevent the inner `Vec<T>` from attempting to deallocate memory.
#[unsafe_destructor]
impl<'a, T> Drop for DerefVec<'a, T> {
fn drop(&mut self) {
self.x.len = 0;
self.x.cap = 0;
}
}
/// Convert a slice to a wrapper type providing a `&Vec<T>` reference.
#[experimental]
pub fn as_vec<'a, T>(x: &'a [T]) -> DerefVec<'a, T> {
unsafe {
DerefVec {
x: Vec::from_raw_parts(x.as_ptr() as *mut T, x.len(), x.len()),
l: ContravariantLifetime::<'a>
}
}
}
/// Unsafe vector operations.
#[unstable]
pub mod raw {
use super::Vec;
use core::ptr;
use core::slice::SlicePrelude;
/// Constructs a vector from an unsafe pointer to a buffer.
///
/// The elements of the buffer are copied into the vector without cloning,
/// as if `ptr::read()` were called on them.
#[inline]
#[unstable]
pub unsafe fn from_buf<T>(ptr: *const T, elts: uint) -> Vec<T> {
let mut dst = Vec::with_capacity(elts);
dst.set_len(elts);
ptr::copy_nonoverlapping_memory(dst.as_mut_ptr(), ptr, elts);
dst
}
}
/// An owned, partially type-converted vector of elements with non-zero size.
///
/// `T` and `U` must have the same, non-zero size. They must also have the same
/// alignment.
///
/// When the destructor of this struct runs, all `U`s from `start_u` (incl.) to
/// `end_u` (excl.) and all `T`s from `start_t` (incl.) to `end_t` (excl.) are
/// destructed. Additionally the underlying storage of `vec` will be freed.
struct PartialVecNonZeroSized<T,U> {
vec: Vec<T>,
start_u: *mut U,
end_u: *mut U,
start_t: *mut T,
end_t: *mut T,
}
/// An owned, partially type-converted vector of zero-sized elements.
///
/// When the destructor of this struct runs, all `num_t` `T`s and `num_u` `U`s
/// are destructed.
struct PartialVecZeroSized<T,U> {
num_t: uint,
num_u: uint,
marker_t: InvariantType<T>,
marker_u: InvariantType<U>,
}
#[unsafe_destructor]
impl<T,U> Drop for PartialVecNonZeroSized<T,U> {
fn drop(&mut self) {
unsafe {
// `vec` hasn't been modified until now. As it has a length
// currently, this would run destructors of `T`s which might not be
// there. So at first, set `vec`s length to `0`. This must be done
// at first to remain memory-safe as the destructors of `U` or `T`
// might cause unwinding where `vec`s destructor would be executed.
self.vec.set_len(0);
// We have instances of `U`s and `T`s in `vec`. Destruct them.
while self.start_u != self.end_u {
let _ = ptr::read(self.start_u as *const U); // Run a `U` destructor.
self.start_u = self.start_u.offset(1);
}
while self.start_t != self.end_t {
let _ = ptr::read(self.start_t as *const T); // Run a `T` destructor.
self.start_t = self.start_t.offset(1);
}
// After this destructor ran, the destructor of `vec` will run,
// deallocating the underlying memory.
}
}
}
#[unsafe_destructor]
impl<T,U> Drop for PartialVecZeroSized<T,U> {
fn drop(&mut self) {
unsafe {
// Destruct the instances of `T` and `U` this struct owns.
while self.num_t != 0 {
let _: T = mem::uninitialized(); // Run a `T` destructor.
self.num_t -= 1;
}
while self.num_u != 0 {
let _: U = mem::uninitialized(); // Run a `U` destructor.
self.num_u -= 1;
}
}
}
}
impl<T> Vec<T> {
/// Converts a `Vec<T>` to a `Vec<U>` where `T` and `U` have the same
/// size and in case they are not zero-sized the same minimal alignment.
///
/// # Panics
///
/// Panics if `T` and `U` have differing sizes or are not zero-sized and
/// have differing minimal alignments.
///
/// # Example
///
/// ```
/// let v = vec![0u, 1, 2];
/// let w = v.map_in_place(|i| i + 3);
/// assert_eq!(w.as_slice(), [3, 4, 5].as_slice());
///
/// #[deriving(PartialEq, Show)]
/// struct Newtype(u8);
/// let bytes = vec![0x11, 0x22];
/// let newtyped_bytes = bytes.map_in_place(|x| Newtype(x));
/// assert_eq!(newtyped_bytes.as_slice(), [Newtype(0x11), Newtype(0x22)].as_slice());
/// ```
pub fn map_in_place<U>(self, f: |T| -> U) -> Vec<U> {
// FIXME: Assert statically that the types `T` and `U` have the same
// size.
assert!(mem::size_of::<T>() == mem::size_of::<U>());
let mut vec = self;
if mem::size_of::<T>() != 0 {
// FIXME: Assert statically that the types `T` and `U` have the
// same minimal alignment in case they are not zero-sized.
// These asserts are necessary because the `min_align_of` of the
// types are passed to the allocator by `Vec`.
assert!(mem::min_align_of::<T>() == mem::min_align_of::<U>());
// This `as int` cast is safe, because the size of the elements of the
// vector is not 0, and:
//
// 1) If the size of the elements in the vector is 1, the `int` may
// overflow, but it has the correct bit pattern so that the
// `.offset()` function will work.
//
// Example:
// Address space 0x0-0xF.
// `u8` array at: 0x1.
// Size of `u8` array: 0x8.
// Calculated `offset`: -0x8.
// After `array.offset(offset)`: 0x9.
// (0x1 + 0x8 = 0x1 - 0x8)
//
// 2) If the size of the elements in the vector is >1, the `uint` ->
// `int` conversion can't overflow.
let offset = vec.len() as int;
let start = vec.as_mut_ptr();
let mut pv = PartialVecNonZeroSized {
vec: vec,
start_t: start,
// This points inside the vector, as the vector has length
// `offset`.
end_t: unsafe { start.offset(offset) },
start_u: start as *mut U,
end_u: start as *mut U,
};
// start_t
// start_u
// |
// +-+-+-+-+-+-+
// |T|T|T|...|T|
// +-+-+-+-+-+-+
// | |
// end_u end_t
while pv.end_u as *mut T != pv.end_t {
unsafe {
// start_u start_t
// | |
// +-+-+-+-+-+-+-+-+-+
// |U|...|U|T|T|...|T|
// +-+-+-+-+-+-+-+-+-+
// | |
// end_u end_t
let t = ptr::read(pv.start_t as *const T);
// start_u start_t
// | |
// +-+-+-+-+-+-+-+-+-+
// |U|...|U|X|T|...|T|
// +-+-+-+-+-+-+-+-+-+
// | |
// end_u end_t
// We must not panic here, one cell is marked as `T`
// although it is not `T`.
pv.start_t = pv.start_t.offset(1);
// start_u start_t
// | |
// +-+-+-+-+-+-+-+-+-+
// |U|...|U|X|T|...|T|
// +-+-+-+-+-+-+-+-+-+
// | |
// end_u end_t
// We may panic again.
// The function given by the user might panic.
let u = f(t);
ptr::write(pv.end_u, u);
// start_u start_t
// | |
// +-+-+-+-+-+-+-+-+-+
// |U|...|U|U|T|...|T|
// +-+-+-+-+-+-+-+-+-+
// | |
// end_u end_t
// We should not panic here, because that would leak the `U`
// pointed to by `end_u`.
pv.end_u = pv.end_u.offset(1);
// start_u start_t
// | |
// +-+-+-+-+-+-+-+-+-+
// |U|...|U|U|T|...|T|
// +-+-+-+-+-+-+-+-+-+
// | |
// end_u end_t
// We may panic again.
}
}
// start_u start_t
// | |
// +-+-+-+-+-+-+
// |U|...|U|U|U|
// +-+-+-+-+-+-+
// |
// end_t
// end_u
// Extract `vec` and prevent the destructor of
// `PartialVecNonZeroSized` from running. Note that none of the
// function calls can panic, thus no resources can be leaked (as the
// `vec` member of `PartialVec` is the only one which holds
// allocations -- and it is returned from this function. None of
// this can panic.
unsafe {
let vec_len = pv.vec.len();
let vec_cap = pv.vec.capacity();
let vec_ptr = pv.vec.as_mut_ptr() as *mut U;
mem::forget(pv);
Vec::from_raw_parts(vec_ptr, vec_len, vec_cap)
}
} else {
// Put the `Vec` into the `PartialVecZeroSized` structure and
// prevent the destructor of the `Vec` from running. Since the
// `Vec` contained zero-sized objects, it did not allocate, so we
// are not leaking memory here.
let mut pv = PartialVecZeroSized::<T,U> {
num_t: vec.len(),
num_u: 0,
marker_t: InvariantType,
marker_u: InvariantType,
};
unsafe { mem::forget(vec); }
while pv.num_t != 0 {
unsafe {
// Create a `T` out of thin air and decrement `num_t`. This
// must not panic between these steps, as otherwise a
// destructor of `T` which doesn't exist runs.
let t = mem::uninitialized();
pv.num_t -= 1;
// The function given by the user might panic.
let u = f(t);
// Forget the `U` and increment `num_u`. This increment
// cannot overflow the `uint` as we only do this for a
// number of times that fits into a `uint` (and start with
// `0`). Again, we should not panic between these steps.
mem::forget(u);
pv.num_u += 1;
}
}
// Create a `Vec` from our `PartialVecZeroSized` and make sure the
// destructor of the latter will not run. None of this can panic.
let mut result = Vec::new();
unsafe { result.set_len(pv.num_u); }
result
}
}
}
#[cfg(test)]
mod tests {
extern crate test;
use std::prelude::*;
use std::mem::size_of;
use test::Bencher;
use super::{as_vec, unzip, raw, Vec};
struct DropCounter<'a> {
count: &'a mut int
}
#[unsafe_destructor]
impl<'a> Drop for DropCounter<'a> {
fn drop(&mut self) {
*self.count += 1;
}
}
#[test]
fn test_as_vec() {
let xs = [1u8, 2u8, 3u8];
assert_eq!(as_vec(xs).as_slice(), xs.as_slice());
}
#[test]
fn test_as_vec_dtor() {
let (mut count_x, mut count_y) = (0, 0);
{
let xs = &[DropCounter { count: &mut count_x }, DropCounter { count: &mut count_y }];
assert_eq!(as_vec(xs).len(), 2);
}
assert_eq!(count_x, 1);
assert_eq!(count_y, 1);
}
#[test]
fn test_small_vec_struct() {
assert!(size_of::<Vec<u8>>() == size_of::<uint>() * 3);
}
#[test]
fn test_double_drop() {
struct TwoVec<T> {
x: Vec<T>,
y: Vec<T>
}
let (mut count_x, mut count_y) = (0, 0);
{
let mut tv = TwoVec {
x: Vec::new(),
y: Vec::new()
};
tv.x.push(DropCounter {count: &mut count_x});
tv.y.push(DropCounter {count: &mut count_y});
// If Vec had a drop flag, here is where it would be zeroed.
// Instead, it should rely on its internal state to prevent
// doing anything significant when dropped multiple times.
drop(tv.x);
// Here tv goes out of scope, tv.y should be dropped, but not tv.x.
}
assert_eq!(count_x, 1);
assert_eq!(count_y, 1);
}
#[test]
fn test_reserve() {
let mut v = Vec::new();
assert_eq!(v.capacity(), 0);
v.reserve(2);
assert!(v.capacity() >= 2);
for i in range(0i, 16) {
v.push(i);
}
assert!(v.capacity() >= 16);
v.reserve(16);
assert!(v.capacity() >= 32);
v.push(16);
v.reserve(16);
assert!(v.capacity() >= 33)
}
#[test]
fn test_extend() {
let mut v = Vec::new();
let mut w = Vec::new();
v.extend(range(0i, 3));
for i in range(0i, 3) { w.push(i) }
assert_eq!(v, w);
v.extend(range(3i, 10));
for i in range(3i, 10) { w.push(i) }
assert_eq!(v, w);
}
#[test]
fn test_slice_from_mut() {
let mut values = vec![1u8,2,3,4,5];
{
let slice = values.slice_from_mut(2);
assert!(slice == [3, 4, 5]);
for p in slice.iter_mut() {
*p += 2;
}
}
assert!(values.as_slice() == [1, 2, 5, 6, 7]);
}
#[test]
fn test_slice_to_mut() {
let mut values = vec![1u8,2,3,4,5];
{
let slice = values.slice_to_mut(2);
assert!(slice == [1, 2]);
for p in slice.iter_mut() {
*p += 1;
}
}
assert!(values.as_slice() == [2, 3, 3, 4, 5]);
}
#[test]
fn test_split_at_mut() {
let mut values = vec![1u8,2,3,4,5];
{
let (left, right) = values.split_at_mut(2);
{
let left: &[_] = left;
assert!(left[0..left.len()] == [1, 2][]);
}
for p in left.iter_mut() {
*p += 1;
}
{
let right: &[_] = right;
assert!(right[0..right.len()] == [3, 4, 5][]);
}
for p in right.iter_mut() {
*p += 2;
}
}
assert!(values == vec![2u8, 3, 5, 6, 7]);
}
#[test]
fn test_clone() {
let v: Vec<int> = vec!();
let w = vec!(1i, 2, 3);
assert_eq!(v, v.clone());
let z = w.clone();
assert_eq!(w, z);
// they should be disjoint in memory.
assert!(w.as_ptr() != z.as_ptr())
}
#[test]
fn test_clone_from() {
let mut v = vec!();
let three = vec!(box 1i, box 2, box 3);
let two = vec!(box 4i, box 5);
// zero, long
v.clone_from(&three);
assert_eq!(v, three);
// equal
v.clone_from(&three);
assert_eq!(v, three);
// long, short
v.clone_from(&two);
assert_eq!(v, two);
// short, long
v.clone_from(&three);
assert_eq!(v, three)
}
#[test]
fn test_grow_fn() {
let mut v = vec![0u, 1];
v.grow_fn(3, |i| i);
assert!(v == vec![0u, 1, 0, 1, 2]);
}
#[test]
fn test_retain() {
let mut vec = vec![1u, 2, 3, 4];
vec.retain(|&x| x % 2 == 0);
assert!(vec == vec![2u, 4]);
}
#[test]
fn zero_sized_values() {
let mut v = Vec::new();
assert_eq!(v.len(), 0);
v.push(());
assert_eq!(v.len(), 1);
v.push(());
assert_eq!(v.len(), 2);
assert_eq!(v.pop(), Some(()));
assert_eq!(v.pop(), Some(()));
assert_eq!(v.pop(), None);
assert_eq!(v.iter().count(), 0);
v.push(());
assert_eq!(v.iter().count(), 1);
v.push(());
assert_eq!(v.iter().count(), 2);
for &() in v.iter() {}
assert_eq!(v.iter_mut().count(), 2);
v.push(());
assert_eq!(v.iter_mut().count(), 3);
v.push(());
assert_eq!(v.iter_mut().count(), 4);
for &() in v.iter_mut() {}
unsafe { v.set_len(0); }
assert_eq!(v.iter_mut().count(), 0);
}
#[test]
fn test_partition() {
assert_eq!(vec![].partition(|x: &int| *x < 3), (vec![], vec![]));
assert_eq!(vec![1i, 2, 3].partition(|x: &int| *x < 4), (vec![1, 2, 3], vec![]));
assert_eq!(vec![1i, 2, 3].partition(|x: &int| *x < 2), (vec![1], vec![2, 3]));
assert_eq!(vec![1i, 2, 3].partition(|x: &int| *x < 0), (vec![], vec![1, 2, 3]));
}
#[test]
fn test_partitioned() {
assert_eq!(vec![].partitioned(|x: &int| *x < 3), (vec![], vec![]))
assert_eq!(vec![1i, 2, 3].partitioned(|x: &int| *x < 4), (vec![1, 2, 3], vec![]));
assert_eq!(vec![1i, 2, 3].partitioned(|x: &int| *x < 2), (vec![1], vec![2, 3]));
assert_eq!(vec![1i, 2, 3].partitioned(|x: &int| *x < 0), (vec![], vec![1, 2, 3]));
}
#[test]
fn test_zip_unzip() {
let z1 = vec![(1i, 4i), (2, 5), (3, 6)];
let (left, right) = unzip(z1.iter().map(|&x| x));
let (left, right) = (left.as_slice(), right.as_slice());
assert_eq!((1, 4), (left[0], right[0]));
assert_eq!((2, 5), (left[1], right[1]));
assert_eq!((3, 6), (left[2], right[2]));
}
#[test]
fn test_unsafe_ptrs() {
unsafe {
// Test on-stack copy-from-buf.
let a = [1i, 2, 3];
let ptr = a.as_ptr();
let b = raw::from_buf(ptr, 3u);
assert_eq!(b, vec![1, 2, 3]);
// Test on-heap copy-from-buf.
let c = vec![1i, 2, 3, 4, 5];
let ptr = c.as_ptr();
let d = raw::from_buf(ptr, 5u);
assert_eq!(d, vec![1, 2, 3, 4, 5]);
}
}
#[test]
fn test_vec_truncate_drop() {
static mut drops: uint = 0;
struct Elem(int);
impl Drop for Elem {
fn drop(&mut self) {
unsafe { drops += 1; }
}
}
let mut v = vec![Elem(1), Elem(2), Elem(3), Elem(4), Elem(5)];
assert_eq!(unsafe { drops }, 0);
v.truncate(3);
assert_eq!(unsafe { drops }, 2);
v.truncate(0);
assert_eq!(unsafe { drops }, 5);
}
#[test]
#[should_fail]
fn test_vec_truncate_fail() {
struct BadElem(int);
impl Drop for BadElem {
fn drop(&mut self) {
let BadElem(ref mut x) = *self;
if *x == 0xbadbeef {
panic!("BadElem panic: 0xbadbeef")
}
}
}
let mut v = vec![BadElem(1), BadElem(2), BadElem(0xbadbeef), BadElem(4)];
v.truncate(0);
}
#[test]
fn test_index() {
let vec = vec!(1i, 2, 3);
assert!(vec[1] == 2);
}
#[test]
#[should_fail]
fn test_index_out_of_bounds() {
let vec = vec!(1i, 2, 3);
let _ = vec[3];
}
#[test]
#[should_fail]
fn test_slice_out_of_bounds_1() {
let x: Vec<int> = vec![1, 2, 3, 4, 5];
x[-1..];
}
#[test]
#[should_fail]
fn test_slice_out_of_bounds_2() {
let x: Vec<int> = vec![1, 2, 3, 4, 5];
x[..6];
}
#[test]
#[should_fail]
fn test_slice_out_of_bounds_3() {
let x: Vec<int> = vec![1, 2, 3, 4, 5];
x[-1..4];
}
#[test]
#[should_fail]
fn test_slice_out_of_bounds_4() {
let x: Vec<int> = vec![1, 2, 3, 4, 5];
x[1..6];
}
#[test]
#[should_fail]
fn test_slice_out_of_bounds_5() {
let x: Vec<int> = vec![1, 2, 3, 4, 5];
x[3..2];
}
#[test]
fn test_swap_remove_empty() {
let mut vec: Vec<uint> = vec!();
assert_eq!(vec.swap_remove(0), None);
}
#[test]
fn test_move_iter_unwrap() {
let mut vec: Vec<uint> = Vec::with_capacity(7);
vec.push(1);
vec.push(2);
let ptr = vec.as_ptr();
vec = vec.into_iter().unwrap();
assert_eq!(vec.as_ptr(), ptr);
assert_eq!(vec.capacity(), 7);
assert_eq!(vec.len(), 0);
}
#[test]
#[should_fail]
fn test_map_in_place_incompatible_types_fail() {
let v = vec![0u, 1, 2];
v.map_in_place(|_| ());
}
#[test]
fn test_map_in_place() {
let v = vec![0u, 1, 2];
assert_eq!(v.map_in_place(|i: uint| i as int - 1).as_slice(), [-1i, 0, 1].as_slice());
}
#[test]
fn test_map_in_place_zero_sized() {
let v = vec![(), ()];
#[deriving(PartialEq, Show)]
struct ZeroSized;
assert_eq!(v.map_in_place(|_| ZeroSized).as_slice(), [ZeroSized, ZeroSized].as_slice());
}
#[test]
fn test_move_items() {
let vec = vec![1, 2, 3];
let mut vec2 : Vec<i32> = vec![];
for i in vec.into_iter() {
vec2.push(i);
}
assert!(vec2 == vec![1, 2, 3]);
}
#[test]
fn test_move_items_reverse() {
let vec = vec![1, 2, 3];
let mut vec2 : Vec<i32> = vec![];
for i in vec.into_iter().rev() {
vec2.push(i);
}
assert!(vec2 == vec![3, 2, 1]);
}
#[test]
fn test_move_items_zero_sized() {
let vec = vec![(), (), ()];
let mut vec2 : Vec<()> = vec![];
for i in vec.into_iter() {
vec2.push(i);
}
assert!(vec2 == vec![(), (), ()]);
}
#[test]
fn test_into_boxed_slice() {
let xs = vec![1u, 2, 3];
let ys = xs.into_boxed_slice();
assert_eq!(ys.as_slice(), [1u, 2, 3].as_slice());
}
#[bench]
fn bench_new(b: &mut Bencher) {
b.iter(|| {
let v: Vec<uint> = Vec::new();
assert_eq!(v.len(), 0);
assert_eq!(v.capacity(), 0);
})
}
fn do_bench_with_capacity(b: &mut Bencher, src_len: uint) {
b.bytes = src_len as u64;
b.iter(|| {
let v: Vec<uint> = Vec::with_capacity(src_len);
assert_eq!(v.len(), 0);
assert_eq!(v.capacity(), src_len);
})
}
#[bench]
fn bench_with_capacity_0000(b: &mut Bencher) {
do_bench_with_capacity(b, 0)
}
#[bench]
fn bench_with_capacity_0010(b: &mut Bencher) {
do_bench_with_capacity(b, 10)
}
#[bench]
fn bench_with_capacity_0100(b: &mut Bencher) {
do_bench_with_capacity(b, 100)
}
#[bench]
fn bench_with_capacity_1000(b: &mut Bencher) {
do_bench_with_capacity(b, 1000)
}
fn do_bench_from_fn(b: &mut Bencher, src_len: uint) {
b.bytes = src_len as u64;
b.iter(|| {
let dst = Vec::from_fn(src_len, |i| i);
assert_eq!(dst.len(), src_len);
assert!(dst.iter().enumerate().all(|(i, x)| i == *x));
})
}
#[bench]
fn bench_from_fn_0000(b: &mut Bencher) {
do_bench_from_fn(b, 0)
}
#[bench]
fn bench_from_fn_0010(b: &mut Bencher) {
do_bench_from_fn(b, 10)
}
#[bench]
fn bench_from_fn_0100(b: &mut Bencher) {
do_bench_from_fn(b, 100)
}
#[bench]
fn bench_from_fn_1000(b: &mut Bencher) {
do_bench_from_fn(b, 1000)
}
fn do_bench_from_elem(b: &mut Bencher, src_len: uint) {
b.bytes = src_len as u64;
b.iter(|| {
let dst: Vec<uint> = Vec::from_elem(src_len, 5);
assert_eq!(dst.len(), src_len);
assert!(dst.iter().all(|x| *x == 5));
})
}
#[bench]
fn bench_from_elem_0000(b: &mut Bencher) {
do_bench_from_elem(b, 0)
}
#[bench]
fn bench_from_elem_0010(b: &mut Bencher) {
do_bench_from_elem(b, 10)
}
#[bench]
fn bench_from_elem_0100(b: &mut Bencher) {
do_bench_from_elem(b, 100)
}
#[bench]
fn bench_from_elem_1000(b: &mut Bencher) {
do_bench_from_elem(b, 1000)
}
fn do_bench_from_slice(b: &mut Bencher, src_len: uint) {
let src: Vec<uint> = FromIterator::from_iter(range(0, src_len));
b.bytes = src_len as u64;
b.iter(|| {
let dst = src.clone().as_slice().to_vec();
assert_eq!(dst.len(), src_len);
assert!(dst.iter().enumerate().all(|(i, x)| i == *x));
});
}
#[bench]
fn bench_from_slice_0000(b: &mut Bencher) {
do_bench_from_slice(b, 0)
}
#[bench]
fn bench_from_slice_0010(b: &mut Bencher) {
do_bench_from_slice(b, 10)
}
#[bench]
fn bench_from_slice_0100(b: &mut Bencher) {
do_bench_from_slice(b, 100)
}
#[bench]
fn bench_from_slice_1000(b: &mut Bencher) {
do_bench_from_slice(b, 1000)
}
fn do_bench_from_iter(b: &mut Bencher, src_len: uint) {
let src: Vec<uint> = FromIterator::from_iter(range(0, src_len));
b.bytes = src_len as u64;
b.iter(|| {
let dst: Vec<uint> = FromIterator::from_iter(src.clone().into_iter());
assert_eq!(dst.len(), src_len);
assert!(dst.iter().enumerate().all(|(i, x)| i == *x));
});
}
#[bench]
fn bench_from_iter_0000(b: &mut Bencher) {
do_bench_from_iter(b, 0)
}
#[bench]
fn bench_from_iter_0010(b: &mut Bencher) {
do_bench_from_iter(b, 10)
}
#[bench]
fn bench_from_iter_0100(b: &mut Bencher) {
do_bench_from_iter(b, 100)
}
#[bench]
fn bench_from_iter_1000(b: &mut Bencher) {
do_bench_from_iter(b, 1000)
}
fn do_bench_extend(b: &mut Bencher, dst_len: uint, src_len: uint) {
let dst: Vec<uint> = FromIterator::from_iter(range(0, dst_len));
let src: Vec<uint> = FromIterator::from_iter(range(dst_len, dst_len + src_len));
b.bytes = src_len as u64;
b.iter(|| {
let mut dst = dst.clone();
dst.extend(src.clone().into_iter());
assert_eq!(dst.len(), dst_len + src_len);
assert!(dst.iter().enumerate().all(|(i, x)| i == *x));
});
}
#[bench]
fn bench_extend_0000_0000(b: &mut Bencher) {
do_bench_extend(b, 0, 0)
}
#[bench]
fn bench_extend_0000_0010(b: &mut Bencher) {
do_bench_extend(b, 0, 10)
}
#[bench]
fn bench_extend_0000_0100(b: &mut Bencher) {
do_bench_extend(b, 0, 100)
}
#[bench]
fn bench_extend_0000_1000(b: &mut Bencher) {
do_bench_extend(b, 0, 1000)
}
#[bench]
fn bench_extend_0010_0010(b: &mut Bencher) {
do_bench_extend(b, 10, 10)
}
#[bench]
fn bench_extend_0100_0100(b: &mut Bencher) {
do_bench_extend(b, 100, 100)
}
#[bench]
fn bench_extend_1000_1000(b: &mut Bencher) {
do_bench_extend(b, 1000, 1000)
}
fn do_bench_push_all(b: &mut Bencher, dst_len: uint, src_len: uint) {
let dst: Vec<uint> = FromIterator::from_iter(range(0, dst_len));
let src: Vec<uint> = FromIterator::from_iter(range(dst_len, dst_len + src_len));
b.bytes = src_len as u64;
b.iter(|| {
let mut dst = dst.clone();
dst.push_all(src.as_slice());
assert_eq!(dst.len(), dst_len + src_len);
assert!(dst.iter().enumerate().all(|(i, x)| i == *x));
});
}
#[bench]
fn bench_push_all_0000_0000(b: &mut Bencher) {
do_bench_push_all(b, 0, 0)
}
#[bench]
fn bench_push_all_0000_0010(b: &mut Bencher) {
do_bench_push_all(b, 0, 10)
}
#[bench]
fn bench_push_all_0000_0100(b: &mut Bencher) {
do_bench_push_all(b, 0, 100)
}
#[bench]
fn bench_push_all_0000_1000(b: &mut Bencher) {
do_bench_push_all(b, 0, 1000)
}
#[bench]
fn bench_push_all_0010_0010(b: &mut Bencher) {
do_bench_push_all(b, 10, 10)
}
#[bench]
fn bench_push_all_0100_0100(b: &mut Bencher) {
do_bench_push_all(b, 100, 100)
}
#[bench]
fn bench_push_all_1000_1000(b: &mut Bencher) {
do_bench_push_all(b, 1000, 1000)
}
fn do_bench_push_all_move(b: &mut Bencher, dst_len: uint, src_len: uint) {
let dst: Vec<uint> = FromIterator::from_iter(range(0u, dst_len));
let src: Vec<uint> = FromIterator::from_iter(range(dst_len, dst_len + src_len));
b.bytes = src_len as u64;
b.iter(|| {
let mut dst = dst.clone();
dst.extend(src.clone().into_iter());
assert_eq!(dst.len(), dst_len + src_len);
assert!(dst.iter().enumerate().all(|(i, x)| i == *x));
});
}
#[bench]
fn bench_push_all_move_0000_0000(b: &mut Bencher) {
do_bench_push_all_move(b, 0, 0)
}
#[bench]
fn bench_push_all_move_0000_0010(b: &mut Bencher) {
do_bench_push_all_move(b, 0, 10)
}
#[bench]
fn bench_push_all_move_0000_0100(b: &mut Bencher) {
do_bench_push_all_move(b, 0, 100)
}
#[bench]
fn bench_push_all_move_0000_1000(b: &mut Bencher) {
do_bench_push_all_move(b, 0, 1000)
}
#[bench]
fn bench_push_all_move_0010_0010(b: &mut Bencher) {
do_bench_push_all_move(b, 10, 10)
}
#[bench]
fn bench_push_all_move_0100_0100(b: &mut Bencher) {
do_bench_push_all_move(b, 100, 100)
}
#[bench]
fn bench_push_all_move_1000_1000(b: &mut Bencher) {
do_bench_push_all_move(b, 1000, 1000)
}
fn do_bench_clone(b: &mut Bencher, src_len: uint) {
let src: Vec<uint> = FromIterator::from_iter(range(0, src_len));
b.bytes = src_len as u64;
b.iter(|| {
let dst = src.clone();
assert_eq!(dst.len(), src_len);
assert!(dst.iter().enumerate().all(|(i, x)| i == *x));
});
}
#[bench]
fn bench_clone_0000(b: &mut Bencher) {
do_bench_clone(b, 0)
}
#[bench]
fn bench_clone_0010(b: &mut Bencher) {
do_bench_clone(b, 10)
}
#[bench]
fn bench_clone_0100(b: &mut Bencher) {
do_bench_clone(b, 100)
}
#[bench]
fn bench_clone_1000(b: &mut Bencher) {
do_bench_clone(b, 1000)
}
fn do_bench_clone_from(b: &mut Bencher, times: uint, dst_len: uint, src_len: uint) {
let dst: Vec<uint> = FromIterator::from_iter(range(0, src_len));
let src: Vec<uint> = FromIterator::from_iter(range(dst_len, dst_len + src_len));
b.bytes = (times * src_len) as u64;
b.iter(|| {
let mut dst = dst.clone();
for _ in range(0, times) {
dst.clone_from(&src);
assert_eq!(dst.len(), src_len);
assert!(dst.iter().enumerate().all(|(i, x)| dst_len + i == *x));
}
});
}
#[bench]
fn bench_clone_from_01_0000_0000(b: &mut Bencher) {
do_bench_clone_from(b, 1, 0, 0)
}
#[bench]
fn bench_clone_from_01_0000_0010(b: &mut Bencher) {
do_bench_clone_from(b, 1, 0, 10)
}
#[bench]
fn bench_clone_from_01_0000_0100(b: &mut Bencher) {
do_bench_clone_from(b, 1, 0, 100)
}
#[bench]
fn bench_clone_from_01_0000_1000(b: &mut Bencher) {
do_bench_clone_from(b, 1, 0, 1000)
}
#[bench]
fn bench_clone_from_01_0010_0010(b: &mut Bencher) {
do_bench_clone_from(b, 1, 10, 10)
}
#[bench]
fn bench_clone_from_01_0100_0100(b: &mut Bencher) {
do_bench_clone_from(b, 1, 100, 100)
}
#[bench]
fn bench_clone_from_01_1000_1000(b: &mut Bencher) {
do_bench_clone_from(b, 1, 1000, 1000)
}
#[bench]
fn bench_clone_from_01_0010_0100(b: &mut Bencher) {
do_bench_clone_from(b, 1, 10, 100)
}
#[bench]
fn bench_clone_from_01_0100_1000(b: &mut Bencher) {
do_bench_clone_from(b, 1, 100, 1000)
}
#[bench]
fn bench_clone_from_01_0010_0000(b: &mut Bencher) {
do_bench_clone_from(b, 1, 10, 0)
}
#[bench]
fn bench_clone_from_01_0100_0010(b: &mut Bencher) {
do_bench_clone_from(b, 1, 100, 10)
}
#[bench]
fn bench_clone_from_01_1000_0100(b: &mut Bencher) {
do_bench_clone_from(b, 1, 1000, 100)
}
#[bench]
fn bench_clone_from_10_0000_0000(b: &mut Bencher) {
do_bench_clone_from(b, 10, 0, 0)
}
#[bench]
fn bench_clone_from_10_0000_0010(b: &mut Bencher) {
do_bench_clone_from(b, 10, 0, 10)
}
#[bench]
fn bench_clone_from_10_0000_0100(b: &mut Bencher) {
do_bench_clone_from(b, 10, 0, 100)
}
#[bench]
fn bench_clone_from_10_0000_1000(b: &mut Bencher) {
do_bench_clone_from(b, 10, 0, 1000)
}
#[bench]
fn bench_clone_from_10_0010_0010(b: &mut Bencher) {
do_bench_clone_from(b, 10, 10, 10)
}
#[bench]
fn bench_clone_from_10_0100_0100(b: &mut Bencher) {
do_bench_clone_from(b, 10, 100, 100)
}
#[bench]
fn bench_clone_from_10_1000_1000(b: &mut Bencher) {
do_bench_clone_from(b, 10, 1000, 1000)
}
#[bench]
fn bench_clone_from_10_0010_0100(b: &mut Bencher) {
do_bench_clone_from(b, 10, 10, 100)
}
#[bench]
fn bench_clone_from_10_0100_1000(b: &mut Bencher) {
do_bench_clone_from(b, 10, 100, 1000)
}
#[bench]
fn bench_clone_from_10_0010_0000(b: &mut Bencher) {
do_bench_clone_from(b, 10, 10, 0)
}
#[bench]
fn bench_clone_from_10_0100_0010(b: &mut Bencher) {
do_bench_clone_from(b, 10, 100, 10)
}
#[bench]
fn bench_clone_from_10_1000_0100(b: &mut Bencher) {
do_bench_clone_from(b, 10, 1000, 100)
}
}