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// 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. //! An owned, growable vector. use cast::{forget, transmute}; use clone::Clone; use cmp::{Ord, Eq, Ordering, TotalEq, TotalOrd}; use container::{Container, Mutable}; use default::Default; use fmt; use iter::{DoubleEndedIterator, FromIterator, Extendable, Iterator}; use libc::{free, c_void}; use mem::{size_of, move_val_init}; use mem; use num; use num::{CheckedMul, CheckedAdd}; use ops::Drop; use option::{None, Option, Some}; use ptr::RawPtr; use ptr; use rt::global_heap::{malloc_raw, realloc_raw}; use raw::Slice; use slice::{ImmutableEqVector, ImmutableVector, Items, MutItems, MutableVector}; use slice::{MutableTotalOrdVector, Vector}; /// An owned, growable vector. /// /// # Examples /// /// ```rust /// # use std::vec::Vec; /// let mut vec = Vec::new(); /// vec.push(1); /// vec.push(2); /// /// assert_eq!(vec.len(), 2); /// assert_eq!(vec.get(0), &1); /// /// assert_eq!(vec.pop(), Some(2)); /// assert_eq!(vec.len(), 1); /// ``` /// /// The `vec!` macro is provided to make initialization more convenient: /// /// ```rust /// let mut vec = vec!(1, 2, 3); /// vec.push(4); /// assert_eq!(vec, vec!(1, 2, 3, 4)); /// ``` #[unsafe_no_drop_flag] pub struct Vec<T> { priv len: uint, priv cap: uint, priv ptr: *mut T } impl<T> Vec<T> { /// Constructs a new, empty `Vec`. /// /// The vector will not allocate until elements are pushed onto it. /// /// # Example /// /// ```rust /// # use std::vec::Vec; /// let mut vec: Vec<int> = Vec::new(); /// ``` #[inline] pub fn new() -> Vec<T> { Vec { len: 0, cap: 0, ptr: 0 as *mut T } } /// 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. /// /// # Example /// /// ```rust /// # use std::vec::Vec; /// let vec: Vec<int> = Vec::with_capacity(10); /// ``` pub fn with_capacity(capacity: uint) -> Vec<T> { if capacity == 0 { Vec::new() } else { let size = capacity.checked_mul(&size_of::<T>()).expect("capacity overflow"); let ptr = unsafe { malloc_raw(size) }; Vec { len: 0, cap: capacity, ptr: ptr as *mut T } } } /// Creates and initializes a `Vec`. /// /// Creates a `Vec` of size `length` and initializes the elements to the /// value returned by the closure `op`. /// /// # Example /// /// ```rust /// # use std::vec::Vec; /// let vec = Vec::from_fn(3, |idx| idx * 2); /// assert_eq!(vec, vec!(0, 2, 4)); /// ``` pub fn from_fn(length: uint, op: |uint| -> T) -> Vec<T> { unsafe { let mut xs = Vec::with_capacity(length); while xs.len < length { move_val_init(xs.as_mut_slice().unsafe_mut_ref(xs.len), op(xs.len)); xs.len += 1; } xs } } /// Create 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 pub unsafe fn from_raw_parts(length: uint, capacity: uint, ptr: *mut T) -> Vec<T> { Vec { len: length, cap: capacity, ptr: ptr } } /// Consumes the `Vec`, partitioning it based on a predcate. /// /// 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 /// /// ```rust /// let vec = vec!(1, 2, 3, 4); /// let (even, odd) = vec.partition(|&n| n % 2 == 0); /// assert_eq!(even, vec!(2, 4)); /// assert_eq!(odd, vec!(1, 3)); /// ``` #[inline] 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.move_iter() { if f(&elt) { lefts.push(elt); } else { rights.push(elt); } } (lefts, rights) } } impl<T: Clone> Vec<T> { /// Iterates over the `second` vector, copying each element and appending it to /// the `first`. Afterwards, the `first` is then returned for use again. /// /// # Example /// /// ```rust /// let vec = vec!(1, 2); /// let vec = vec.append([3, 4]); /// assert_eq!(vec, vec!(1, 2, 3, 4)); /// ``` #[inline] pub fn append(mut self, second: &[T]) -> Vec<T> { self.push_all(second); self } /// Constructs a `Vec` by cloning elements of a slice. /// /// # Example /// /// ```rust /// # use std::vec::Vec; /// let slice = [1, 2, 3]; /// let vec = Vec::from_slice(slice); /// ``` pub fn from_slice(values: &[T]) -> Vec<T> { values.iter().map(|x| x.clone()).collect() } /// Constructs a `Vec` with copies of a value. /// /// Creates a `Vec` with `length` copies of `value`. /// /// # Example /// ```rust /// # use std::vec::Vec; /// let vec = Vec::from_elem(3, "hi"); /// println!("{}", vec); // prints [hi, hi, hi] /// ``` pub fn from_elem(length: uint, value: T) -> Vec<T> { unsafe { let mut xs = Vec::with_capacity(length); while xs.len < length { move_val_init(xs.as_mut_slice().unsafe_mut_ref(xs.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 /// /// ```rust /// let mut vec = vec!(1); /// vec.push_all([2, 3, 4]); /// assert_eq!(vec, vec!(1, 2, 3, 4)); /// ``` #[inline] pub fn push_all(&mut self, other: &[T]) { for element in other.iter() { self.push((*element).clone()) } } /// Grows the `Vec` in-place. /// /// Adds `n` copies of `value` to the `Vec`. /// /// # Example /// /// ```rust /// let mut vec = vec!("hello"); /// vec.grow(2, & &"world"); /// assert_eq!(vec, vec!("hello", "world", "world")); /// ``` pub fn grow(&mut self, n: uint, value: &T) { let new_len = self.len() + n; self.reserve(new_len); let mut i: uint = 0u; while i < n { self.push((*value).clone()); i += 1u; } } /// Sets the value of a vector element at a given index, growing the vector /// as needed. /// /// Sets the element at position `index` to `value`. If `index` is past the /// end of the vector, expands the vector by replicating `initval` to fill /// the intervening space. /// /// # Example /// /// ```rust /// let mut vec = vec!("a", "b", "c"); /// vec.grow_set(1, & &"fill", "d"); /// vec.grow_set(4, & &"fill", "e"); /// assert_eq!(vec, vec!("a", "d", "c", "fill", "e")); /// ``` pub fn grow_set(&mut self, index: uint, initval: &T, value: T) { let l = self.len(); if index >= l { self.grow(index - l + 1u, initval); } *self.get_mut(index) = value; } /// Partitions a vector based on a predcate. /// /// 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 /// /// ```rust /// let vec = vec!(1, 2, 3, 4); /// let (even, odd) = vec.partitioned(|&n| n % 2 == 0); /// assert_eq!(even, vec!(2, 4)); /// assert_eq!(odd, vec!(1, 3)); /// ``` 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) } } impl<T:Clone> Clone for Vec<T> { fn clone(&self) -> Vec<T> { let mut vector = Vec::with_capacity(self.len()); for element in self.iter() { vector.push((*element).clone()) } vector } } impl<T> FromIterator<T> for Vec<T> { 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 } } impl<T> Extendable<T> for Vec<T> { fn extend<I: Iterator<T>>(&mut self, mut iterator: I) { let (lower, _) = iterator.size_hint(); self.reserve_additional(lower); for element in iterator { self.push(element) } } } impl<T: Eq> Eq for Vec<T> { #[inline] fn eq(&self, other: &Vec<T>) -> bool { self.as_slice() == other.as_slice() } } impl<T: Ord> Ord for Vec<T> { #[inline] fn lt(&self, other: &Vec<T>) -> bool { self.as_slice() < other.as_slice() } } impl<T: TotalEq> TotalEq for Vec<T> {} impl<T: TotalOrd> TotalOrd for Vec<T> { #[inline] fn cmp(&self, other: &Vec<T>) -> Ordering { self.as_slice().cmp(&other.as_slice()) } } impl<T> Container for Vec<T> { #[inline] fn len(&self) -> uint { self.len } } impl<T> Vec<T> { /// Returns the number of elements the vector can hold without /// reallocating. /// /// # Example /// /// ```rust /// # use std::vec::Vec; /// let vec: Vec<int> = Vec::with_capacity(10); /// assert_eq!(vec.capacity(), 10); /// ``` #[inline] pub fn capacity(&self) -> uint { self.cap } /// Reserves capacity for at least `n` additional elements in the given /// vector. /// /// # Failure /// /// Fails if the new capacity overflows `uint`. /// /// # Example /// /// ```rust /// # use std::vec::Vec; /// let mut vec: Vec<int> = vec!(1); /// vec.reserve_additional(10); /// assert!(vec.capacity() >= 11); /// ``` pub fn reserve_additional(&mut self, extra: uint) { if self.cap - self.len < extra { match self.len.checked_add(&extra) { None => fail!("Vec::reserve_additional: `uint` overflow"), Some(new_cap) => self.reserve(new_cap) } } } /// Reserves capacity for at least `n` elements in the given vector. /// /// This function will over-allocate in order to amortize the allocation /// costs in scenarios where the caller may need to repeatedly reserve /// additional space. /// /// If the capacity for `self` is already equal to or greater than the /// requested capacity, then no action is taken. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3); /// vec.reserve(10); /// assert!(vec.capacity() >= 10); /// ``` pub fn reserve(&mut self, capacity: uint) { if capacity >= self.len { self.reserve_exact(num::next_power_of_two(capacity)) } } /// 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. /// /// # Example /// /// ```rust /// # use std::vec::Vec; /// let mut vec: Vec<int> = Vec::with_capacity(10); /// vec.reserve_exact(11); /// assert_eq!(vec.capacity(), 11); /// ``` pub fn reserve_exact(&mut self, capacity: uint) { if capacity >= self.len { let size = capacity.checked_mul(&size_of::<T>()).expect("capacity overflow"); self.cap = capacity; unsafe { self.ptr = realloc_raw(self.ptr as *mut u8, size) as *mut T; } } } /// Shrink the capacity of the vector to match the length /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3); /// vec.shrink_to_fit(); /// assert_eq!(vec.capacity(), vec.len()); /// ``` pub fn shrink_to_fit(&mut self) { if self.len == 0 { unsafe { free(self.ptr as *mut c_void) }; self.cap = 0; self.ptr = 0 as *mut T; } else { unsafe { // Overflow check is unnecessary as the vector is already at least this large. self.ptr = realloc_raw(self.ptr as *mut u8, self.len * size_of::<T>()) as *mut T; } self.cap = self.len; } } /// Remove the last element from a vector and return it, or `None` if it is /// empty. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3); /// assert_eq!(vec.pop(), Some(3)); /// assert_eq!(vec, vec!(1, 2)); /// ``` #[inline] pub fn pop(&mut self) -> Option<T> { if self.len == 0 { None } else { unsafe { self.len -= 1; Some(ptr::read(self.as_slice().unsafe_ref(self.len()))) } } } /// Append an element to a vector. /// /// # Failure /// /// Fails if the number of elements in the vector overflows a `uint`. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2); /// vec.push(3); /// assert_eq!(vec, vec!(1, 2, 3)); /// ``` #[inline] pub fn push(&mut self, value: T) { if self.len == self.cap { if self.cap == 0 { self.cap += 2 } let old_size = self.cap * size_of::<T>(); self.cap = self.cap * 2; let size = old_size * 2; if old_size > size { fail!("capacity overflow") } unsafe { self.ptr = realloc_raw(self.ptr as *mut u8, size) as *mut T; } } unsafe { let end = (self.ptr as *T).offset(self.len as int) as *mut T; move_val_init(&mut *end, value); self.len += 1; } } /// Appends one element to the vector provided. The vector itself is then /// returned for use again. /// /// # Example /// /// ```rust /// let vec = vec!(1, 2); /// let vec = vec.append_one(3); /// assert_eq!(vec, vec!(1, 2, 3)); /// ``` #[inline] pub fn append_one(mut self, x: T) -> Vec<T> { self.push(x); self } /// Shorten a vector, dropping excess elements. /// /// If `len` is greater than the vector's current length, this has no /// effect. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3, 4); /// vec.truncate(2); /// assert_eq!(vec, vec!(1, 2)); /// ``` pub fn truncate(&mut self, len: uint) { unsafe { let mut i = len; // drop any extra elements while i < self.len { ptr::read(self.as_slice().unsafe_ref(i)); i += 1; } } self.len = len; } /// Work with `self` as a mutable slice. /// /// # Example /// /// ```rust /// fn foo(slice: &mut [int]) {} /// /// let mut vec = vec!(1, 2); /// foo(vec.as_mut_slice()); /// ``` #[inline] pub fn as_mut_slice<'a>(&'a mut self) -> &'a mut [T] { let slice = Slice { data: self.ptr as *T, len: self.len }; unsafe { transmute(slice) } } /// 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 /// /// ```rust /// let v = vec!(~"a", ~"b"); /// for s in v.move_iter() { /// // s has type ~str, not &~str /// println!("{}", s); /// } /// ``` #[inline] pub fn move_iter(self) -> MoveItems<T> { unsafe { let iter = transmute(self.as_slice().iter()); let ptr = self.ptr as *mut c_void; forget(self); MoveItems { allocation: ptr, iter: iter } } } /// 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. #[inline] pub unsafe fn set_len(&mut self, len: uint) { self.len = len; } /// Returns a reference to the value at index `index`. /// /// # Failure /// /// Fails if `index` is out of bounds /// /// # Example /// /// ```rust /// let vec = vec!(1, 2, 3); /// assert!(vec.get(1) == &2); /// ``` #[inline] pub fn get<'a>(&'a self, index: uint) -> &'a T { &self.as_slice()[index] } /// Returns a mutable reference to the value at index `index`. /// /// # Failure /// /// Fails if `index` is out of bounds /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3); /// *vec.get_mut(1) = 4; /// assert_eq!(vec, vec!(1, 4, 3)); /// ``` #[inline] pub fn get_mut<'a>(&'a mut self, index: uint) -> &'a mut T { &mut self.as_mut_slice()[index] } /// Returns an iterator over references to the elements of the vector in /// order. /// /// # Example /// /// ```rust /// let vec = vec!(1, 2, 3); /// for num in vec.iter() { /// println!("{}", *num); /// } /// ``` #[inline] pub fn iter<'a>(&'a self) -> Items<'a,T> { self.as_slice().iter() } /// Returns an iterator over mutable references to the elements of the /// vector in order. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3); /// for num in vec.mut_iter() { /// *num = 0; /// } /// ``` #[inline] pub fn mut_iter<'a>(&'a mut self) -> MutItems<'a,T> { self.as_mut_slice().mut_iter() } /// Sort the vector, in place, using `compare` to compare elements. /// /// This sort is `O(n log n)` worst-case and stable, but allocates /// approximately `2 * n`, where `n` is the length of `self`. /// /// # Example /// /// ```rust /// let mut v = vec!(5i, 4, 1, 3, 2); /// v.sort_by(|a, b| a.cmp(b)); /// assert_eq!(v, vec!(1, 2, 3, 4, 5)); /// /// // reverse sorting /// v.sort_by(|a, b| b.cmp(a)); /// assert_eq!(v, vec!(5, 4, 3, 2, 1)); /// ``` #[inline] pub fn sort_by(&mut self, compare: |&T, &T| -> Ordering) { self.as_mut_slice().sort_by(compare) } /// Returns a slice of `self` between `start` and `end`. /// /// # Failure /// /// Fails when `start` or `end` point outside the bounds of `self`, or when /// `start` > `end`. /// /// # Example /// /// ```rust /// let vec = vec!(1, 2, 3, 4); /// assert!(vec.slice(0, 2) == [1, 2]); /// ``` #[inline] pub fn slice<'a>(&'a self, start: uint, end: uint) -> &'a [T] { self.as_slice().slice(start, end) } /// Returns a slice containing all but the first element of the vector. /// /// # Failure /// /// Fails when the vector is empty. /// /// # Example /// /// ```rust /// let vec = vec!(1, 2, 3); /// assert!(vec.tail() == [2, 3]); /// ``` #[inline] pub fn tail<'a>(&'a self) -> &'a [T] { self.as_slice().tail() } /// Returns all but the first `n' elements of a vector. /// /// # Failure /// /// Fails when there are fewer than `n` elements in the vector. /// /// # Example /// /// ```rust /// let vec = vec!(1, 2, 3, 4); /// assert!(vec.tailn(2) == [3, 4]); /// ``` #[inline] pub fn tailn<'a>(&'a self, n: uint) -> &'a [T] { self.as_slice().tailn(n) } /// Returns a reference to the last element of a vector, or `None` if it is /// empty. /// /// # Example /// /// ```rust /// let vec = vec!(1, 2, 3); /// assert!(vec.last() == Some(&3)); /// ``` #[inline] pub fn last<'a>(&'a self) -> Option<&'a T> { self.as_slice().last() } /// Returns a mutable reference to the last element of a vector, or `None` /// if it is empty. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3); /// *vec.mut_last().unwrap() = 4; /// assert_eq!(vec, vec!(1, 2, 4)); /// ``` #[inline] pub fn mut_last<'a>(&'a mut self) -> Option<&'a mut T> { self.as_mut_slice().mut_last() } /// Remove 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 /// ```rust /// 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] pub fn swap_remove(&mut self, index: uint) -> Option<T> { let length = self.len(); if index < length - 1 { self.as_mut_slice().swap(index, length - 1); } else if index >= length { return None } self.pop() } /// Prepend an element to the vector. /// /// # Warning /// /// This is an O(n) operation as it requires copying every element in the /// vector. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3); /// vec.unshift(4); /// assert_eq!(vec, vec!(4, 1, 2, 3)); /// ``` #[inline] pub fn unshift(&mut self, element: T) { self.insert(0, element) } /// Removes the first element from a vector and returns it, or `None` if /// the vector is empty. /// /// # Warning /// /// This is an O(n) operation as it requires copying every element in the /// vector. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3); /// assert!(vec.shift() == Some(1)); /// assert_eq!(vec, vec!(2, 3)); /// ``` #[inline] pub fn shift(&mut self) -> Option<T> { self.remove(0) } /// Insert an element at position `index` within the vector, shifting all /// elements after position i one position to the right. /// /// # Failure /// /// Fails if `index` is out of bounds of the vector. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3); /// vec.insert(1, 4); /// assert_eq!(vec, vec!(1, 4, 2, 3)); /// ``` pub fn insert(&mut self, index: uint, element: T) { let len = self.len(); assert!(index <= len); // space for the new element self.reserve(len + 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. move_val_init(&mut *p, element); } self.set_len(len + 1); } } /// Remove and return 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 /// /// ```rust /// let mut v = vec!(1, 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)); /// ``` 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 *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 } } /// Takes ownership of the vector `other`, moving all elements into /// the current vector. This does not copy any elements, and it is /// illegal to use the `other` vector after calling this method /// (because it is moved here). /// /// # Example /// /// ```rust /// let mut vec = vec!(~1); /// vec.push_all_move(vec!(~2, ~3, ~4)); /// assert_eq!(vec, vec!(~1, ~2, ~3, ~4)); /// ``` pub fn push_all_move(&mut self, other: Vec<T>) { for element in other.move_iter() { self.push(element) } } /// Returns a mutable slice of `self` between `start` and `end`. /// /// # Failure /// /// Fails when `start` or `end` point outside the bounds of `self`, or when /// `start` > `end`. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3, 4); /// assert!(vec.mut_slice(0, 2) == [1, 2]); /// ``` #[inline] pub fn mut_slice<'a>(&'a mut self, start: uint, end: uint) -> &'a mut [T] { self.as_mut_slice().mut_slice(start, end) } /// Returns a mutable slice of self from `start` to the end of the vec. /// /// # Failure /// /// Fails when `start` points outside the bounds of self. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3, 4); /// assert!(vec.mut_slice_from(2) == [3, 4]); /// ``` #[inline] pub fn mut_slice_from<'a>(&'a mut self, start: uint) -> &'a mut [T] { self.as_mut_slice().mut_slice_from(start) } /// Returns a mutable slice of self from the start of the vec to `end`. /// /// # Failure /// /// Fails when `end` points outside the bounds of self. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3, 4); /// assert!(vec.mut_slice_to(2) == [1, 2]); /// ``` #[inline] pub fn mut_slice_to<'a>(&'a mut self, end: uint) -> &'a mut [T] { self.as_mut_slice().mut_slice_to(end) } /// Returns a pair of mutable slices that divides the vec at an index. /// /// The first will contain all indices from `[0, mid)` (excluding /// the index `mid` itself) and the second will contain all /// indices from `[mid, len)` (excluding the index `len` itself). /// /// # Failure /// /// Fails if `mid > len`. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 3, 4, 5, 6); /// /// // scoped to restrict the lifetime of the borrows /// { /// let (left, right) = vec.mut_split_at(0); /// assert!(left == &mut []); /// assert!(right == &mut [1, 2, 3, 4, 5, 6]); /// } /// /// { /// let (left, right) = vec.mut_split_at(2); /// assert!(left == &mut [1, 2]); /// assert!(right == &mut [3, 4, 5, 6]); /// } /// /// { /// let (left, right) = vec.mut_split_at(6); /// assert!(left == &mut [1, 2, 3, 4, 5, 6]); /// assert!(right == &mut []); /// } /// ``` #[inline] pub fn mut_split_at<'a>(&'a mut self, mid: uint) -> (&'a mut [T], &'a mut [T]) { self.as_mut_slice().mut_split_at(mid) } /// Reverse the order of elements in a vector, in place. /// /// # Example /// /// ```rust /// let mut v = vec!(1, 2, 3); /// v.reverse(); /// assert_eq!(v, vec!(3, 2, 1)); /// ``` #[inline] pub fn reverse(&mut self) { self.as_mut_slice().reverse() } /// Returns a slice of `self` from `start` to the end of the vec. /// /// # Failure /// /// Fails when `start` points outside the bounds of self. /// /// # Example /// /// ```rust /// let vec = vec!(1, 2, 3); /// assert!(vec.slice_from(1) == [2, 3]); /// ``` #[inline] pub fn slice_from<'a>(&'a self, start: uint) -> &'a [T] { self.as_slice().slice_from(start) } /// Returns a slice of self from the start of the vec to `end`. /// /// # Failure /// /// Fails when `end` points outside the bounds of self. /// /// # Example /// /// ```rust /// let vec = vec!(1, 2, 3); /// assert!(vec.slice_to(2) == [1, 2]); /// ``` #[inline] pub fn slice_to<'a>(&'a self, end: uint) -> &'a [T] { self.as_slice().slice_to(end) } /// Returns a slice containing all but the last element of the vector. /// /// # Failure /// /// Fails if the vector is empty #[inline] pub fn init<'a>(&'a self) -> &'a [T] { self.slice(0, self.len() - 1) } /// Returns an unsafe pointer to the vector's buffer. /// /// The caller must ensure that the vector outlives the pointer this /// function returns, or else it will end up pointing to garbage. /// /// Modifying the vector may cause its buffer to be reallocated, which /// would also make any pointers to it invalid. #[inline] pub fn as_ptr(&self) -> *T { self.as_slice().as_ptr() } /// Returns a mutable unsafe pointer to the vector's buffer. /// /// The caller must ensure that the vector outlives the pointer this /// function returns, or else it will end up pointing to garbage. /// /// Modifying the vector may cause its buffer to be reallocated, which /// would also make any pointers to it invalid. #[inline] pub fn as_mut_ptr(&mut self) -> *mut T { self.as_mut_slice().as_mut_ptr() } } impl<T:TotalOrd> Vec<T> { /// Sorts the vector in place. /// /// This sort is `O(n log n)` worst-case and stable, but allocates /// approximately `2 * n`, where `n` is the length of `self`. /// /// # Example /// /// ```rust /// let mut vec = vec!(3i, 1, 2); /// vec.sort(); /// assert_eq!(vec, vec!(1, 2, 3)); /// ``` pub fn sort(&mut self) { self.as_mut_slice().sort() } } impl<T> Mutable for Vec<T> { #[inline] fn clear(&mut self) { self.truncate(0) } } impl<T:Eq> Vec<T> { /// Return true if a vector contains an element with the given value /// /// # Example /// /// ```rust /// let vec = vec!(1, 2, 3); /// assert!(vec.contains(&1)); /// ``` pub fn contains(&self, x: &T) -> bool { self.as_slice().contains(x) } /// Remove consecutive repeated elements in the vector. /// /// If the vector is sorted, this removes all duplicates. /// /// # Example /// /// ```rust /// let mut vec = vec!(1, 2, 2, 3, 2); /// vec.dedup(); /// assert_eq!(vec, vec!(1, 2, 3, 2)); /// ``` pub fn dedup(&mut self) { unsafe { // Although we have a mutable reference to `self`, we cannot make // *arbitrary* changes. The `Eq` comparisons could fail, 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], tis 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> Vector<T> for Vec<T> { /// Work with `self` as a slice. /// /// # Example /// /// ```rust /// fn foo(slice: &[int]) {} /// /// let vec = vec!(1, 2); /// foo(vec.as_slice()); /// ``` #[inline] fn as_slice<'a>(&'a self) -> &'a [T] { let slice = Slice { data: self.ptr as *T, len: self.len }; unsafe { transmute(slice) } } } #[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]). unsafe { for x in self.as_mut_slice().iter() { ptr::read(x); } free(self.ptr as *mut c_void) } } } impl<T> Default for Vec<T> { fn default() -> Vec<T> { Vec::new() } } 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> { priv allocation: *mut c_void, // the block of memory allocated for the vector priv iter: Items<'static, T> } impl<T> Iterator<T> for MoveItems<T> { #[inline] fn next(&mut self) -> Option<T> { unsafe { self.iter.next().map(|x| ptr::read(x)) } } #[inline] fn size_hint(&self) -> (uint, Option<uint>) { self.iter.size_hint() } } impl<T> DoubleEndedIterator<T> for MoveItems<T> { #[inline] fn next_back(&mut self) -> Option<T> { unsafe { self.iter.next_back().map(|x| ptr::read(x)) } } } #[unsafe_destructor] impl<T> Drop for MoveItems<T> { fn drop(&mut self) { // destroy the remaining elements for _x in *self {} unsafe { free(self.allocation) } } } #[cfg(test)] mod tests { use prelude::*; use mem::size_of; #[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> } struct DropCounter<'a> { count: &'a mut int } #[unsafe_destructor] impl<'a> Drop for DropCounter<'a> { fn drop(&mut self) { *self.count += 1; } } let mut count_x @ mut count_y = 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_additional() { let mut v = Vec::new(); assert_eq!(v.capacity(), 0); v.reserve_additional(2); assert!(v.capacity() >= 2); for i in range(0, 16) { v.push(i); } assert!(v.capacity() >= 16); v.reserve_additional(16); assert!(v.capacity() >= 32); v.push(16); v.reserve_additional(16); assert!(v.capacity() >= 33) } #[test] fn test_extend() { let mut v = Vec::new(); let mut w = Vec::new(); v.extend(range(0, 3)); for i in range(0, 3) { w.push(i) } assert_eq!(v, w); v.extend(range(3, 10)); for i in range(3, 10) { w.push(i) } assert_eq!(v, w); } #[test] fn test_mut_slice_from() { let mut values = Vec::from_slice([1u8,2,3,4,5]); { let slice = values.mut_slice_from(2); assert!(slice == [3, 4, 5]); for p in slice.mut_iter() { *p += 2; } } assert!(values.as_slice() == [1, 2, 5, 6, 7]); } #[test] fn test_mut_slice_to() { let mut values = Vec::from_slice([1u8,2,3,4,5]); { let slice = values.mut_slice_to(2); assert!(slice == [1, 2]); for p in slice.mut_iter() { *p += 1; } } assert!(values.as_slice() == [2, 3, 3, 4, 5]); } #[test] fn test_mut_split_at() { let mut values = Vec::from_slice([1u8,2,3,4,5]); { let (left, right) = values.mut_split_at(2); assert!(left.slice(0, left.len()) == [1, 2]); for p in left.mut_iter() { *p += 1; } assert!(right.slice(0, right.len()) == [3, 4, 5]); for p in right.mut_iter() { *p += 2; } } assert!(values == Vec::from_slice([2u8, 3, 5, 6, 7])); } }