Skip to content

Commit

Permalink
Auto merge of #63045 - Rosto75:master, r=jonas-schievink
Browse files Browse the repository at this point in the history
Change the placement of two functions.

Right now, the order is as follows:
`pop_front()`
`push_front()`
`push_back()`
`pop_back()`

`swap_remove_back()`
`swap_remove_front()`

I believe it would be more natural, and easier to follow, if we place `pop_back()` right after the `pop_front()`, and `swap_remove_back()` after the `swap_remove_front()` like this:
`pop_front()`
`pop_back()`
`push_front()`
`push_back()`

`swap_remove_front()`
`swap_remove_back()`

The rest of the documentation (at least in this module) adheres to the same logic, where the 'front' function always precedes its 'back' equivalent.
  • Loading branch information
bors committed Aug 18, 2019
2 parents 4cf7673 + 98c50eb commit 0ccbae2
Showing 1 changed file with 43 additions and 43 deletions.
86 changes: 43 additions & 43 deletions src/liballoc/collections/vec_deque.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1199,6 +1199,31 @@ impl<T> VecDeque<T> {
}
}

/// Removes the last element from the `VecDeque` and returns it, or `None` if
/// it is empty.
///
/// # Examples
///
/// ```
/// use std::collections::VecDeque;
///
/// let mut buf = VecDeque::new();
/// assert_eq!(buf.pop_back(), None);
/// buf.push_back(1);
/// buf.push_back(3);
/// assert_eq!(buf.pop_back(), Some(3));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn pop_back(&mut self) -> Option<T> {
if self.is_empty() {
None
} else {
self.head = self.wrap_sub(self.head, 1);
let head = self.head;
unsafe { Some(self.buffer_read(head)) }
}
}

/// Prepends an element to the `VecDeque`.
///
/// # Examples
Expand Down Expand Up @@ -1243,38 +1268,13 @@ impl<T> VecDeque<T> {
unsafe { self.buffer_write(head, value) }
}

/// Removes the last element from the `VecDeque` and returns it, or `None` if
/// it is empty.
///
/// # Examples
///
/// ```
/// use std::collections::VecDeque;
///
/// let mut buf = VecDeque::new();
/// assert_eq!(buf.pop_back(), None);
/// buf.push_back(1);
/// buf.push_back(3);
/// assert_eq!(buf.pop_back(), Some(3));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn pop_back(&mut self) -> Option<T> {
if self.is_empty() {
None
} else {
self.head = self.wrap_sub(self.head, 1);
let head = self.head;
unsafe { Some(self.buffer_read(head)) }
}
}

#[inline]
fn is_contiguous(&self) -> bool {
self.tail <= self.head
}

/// Removes an element from anywhere in the `VecDeque` and returns it, replacing it with the
/// last element.
/// Removes an element from anywhere in the `VecDeque` and returns it,
/// replacing it with the first element.
///
/// This does not preserve ordering, but is O(1).
///
Expand All @@ -1288,28 +1288,28 @@ impl<T> VecDeque<T> {
/// use std::collections::VecDeque;
///
/// let mut buf = VecDeque::new();
/// assert_eq!(buf.swap_remove_back(0), None);
/// assert_eq!(buf.swap_remove_front(0), None);
/// buf.push_back(1);
/// buf.push_back(2);
/// buf.push_back(3);
/// assert_eq!(buf, [1, 2, 3]);
///
/// assert_eq!(buf.swap_remove_back(0), Some(1));
/// assert_eq!(buf, [3, 2]);
/// assert_eq!(buf.swap_remove_front(2), Some(3));
/// assert_eq!(buf, [2, 1]);
/// ```
#[stable(feature = "deque_extras_15", since = "1.5.0")]
pub fn swap_remove_back(&mut self, index: usize) -> Option<T> {
pub fn swap_remove_front(&mut self, index: usize) -> Option<T> {
let length = self.len();
if length > 0 && index < length - 1 {
self.swap(index, length - 1);
if length > 0 && index < length && index != 0 {
self.swap(index, 0);
} else if index >= length {
return None;
}
self.pop_back()
self.pop_front()
}

/// Removes an element from anywhere in the `VecDeque` and returns it,
/// replacing it with the first element.
/// Removes an element from anywhere in the `VecDeque` and returns it, replacing it with the
/// last element.
///
/// This does not preserve ordering, but is O(1).
///
Expand All @@ -1323,24 +1323,24 @@ impl<T> VecDeque<T> {
/// use std::collections::VecDeque;
///
/// let mut buf = VecDeque::new();
/// assert_eq!(buf.swap_remove_front(0), None);
/// assert_eq!(buf.swap_remove_back(0), None);
/// buf.push_back(1);
/// buf.push_back(2);
/// buf.push_back(3);
/// assert_eq!(buf, [1, 2, 3]);
///
/// assert_eq!(buf.swap_remove_front(2), Some(3));
/// assert_eq!(buf, [2, 1]);
/// assert_eq!(buf.swap_remove_back(0), Some(1));
/// assert_eq!(buf, [3, 2]);
/// ```
#[stable(feature = "deque_extras_15", since = "1.5.0")]
pub fn swap_remove_front(&mut self, index: usize) -> Option<T> {
pub fn swap_remove_back(&mut self, index: usize) -> Option<T> {
let length = self.len();
if length > 0 && index < length && index != 0 {
self.swap(index, 0);
if length > 0 && index < length - 1 {
self.swap(index, length - 1);
} else if index >= length {
return None;
}
self.pop_front()
self.pop_back()
}

/// Inserts an element at `index` within the `VecDeque`, shifting all elements with indices
Expand Down

0 comments on commit 0ccbae2

Please sign in to comment.