Struct TwoSidedVec 

pub struct TwoSidedVec<T> { /* private fields */ }

A simple ‘two sided’ vector, that can grow both forwards and backwards.

The front and the back can be viewed as seperate and independent vectors, with negative indexing accessing the back and positive indexing accessing the front. This allows you to append to the back without modifying positive indexes. Unless you actually need pushing to the back to appear to shift the front forward, like VecDeque does, this negative index system will probably be better for your situation.

Internally this allows a much simpler and faster implementation, since there’s only a single pointer to the middle that grows up and down. Internally, we have to reallocate the buffer if we run out of capacity in either the negative or positive difes grow separately and Although bounds checks are slightly slower since they involve two comparisons, the access itself should be just as fast.

Implementations

impl<T> TwoSidedVec<T>

pub fn new() -> Self

pub fn with_capacity(back: usize, front: usize) -> Self

pub fn front(&self) -> &[T]

Take a slice of the front of this queue

pub fn back(&self) -> &[T]

Take a slice of the back of this queue

pub fn front_mut(&mut self) -> &mut [T]

Take a mutable slice of the front of this queue

pub fn back_mut(&mut self) -> &mut [T]

Take a mutable slice of the back of this queue

pub fn split(&self) -> (&[T], &[T])

Take seperate slices of the back and the front of the vector respectively.

pub fn split_mut(&mut self) -> (&mut [T], &mut [T])

Take seperate mutable slices of the back and front of the vector respectively.

pub fn push_front(&mut self, value: T)

pub fn pop_front(&mut self) -> Option<T>

pub fn pop_back(&mut self) -> Option<T>

pub fn push_back(&mut self, value: T)

Push the specified value into the front of this queue, without modifying its end or touching the front of the queue.

This effectively preserves all positive indexes, which may or may not be useful for your situation.

pub fn reserve_back(&mut self, amount: usize)

pub fn reserve_front(&mut self, amount: usize)

pub fn capacity_back(&self) -> usize

pub fn capacity_front(&self) -> usize

pub fn len(&self) -> usize

Return the length of the entire vector, which is the sum of the lengths of the front and back parts.

The length isn’t where the vector ends, since it could have elements in the back with negative indexes. Use vec.start() and vec.end() if you want to know the start and end indexes. The total length is exactly equivalent to vec.len_back() + vec.len_front()

pub fn is_empty(&self) -> bool

pub fn len_back(&self) -> usize

Return the length of the back of the vector.

pub fn len_front(&self) -> usize

Return the length of the front of the vector

pub fn start(&self) -> isize

Give the (inclusive) start of the queue’s elements. which may be negative if the queue’s back isn’t empty

This is exactly equivelant to -vec.back().len().

pub fn end(&self) -> isize

Give the (exclusive) end of the queue’s elements, which may be less than the length if the queue’s back contains some elements.

This is exactly equivalent to vec.front().len()

pub fn range(&self) -> Range<isize>

Return the [start, end) range of the element indices, equivalent to a tuple of (queue.start(), queue.end()).

pub fn iter_entire(&self) -> Iter<'_, T>

Iterate over the entire vector, including both the back and front.

pub fn get<I: TwoSidedIndex<T>>(&self, index: I) -> Option<&I::Output>

pub fn get_mut<I: TwoSidedIndex<T>>( &mut self, index: I, ) -> Option<&mut I::Output>

pub unsafe fn get_unchecked<I: TwoSidedIndex<T>>(&self, index: I) -> &I::Output

Get a reference to value at the specified index

Safety

Undefined behavior if the index is out of bounds

pub unsafe fn get_unchecked_mut<I: TwoSidedIndex<T>>( &mut self, index: I, ) -> &mut I::Output

Get a mutable reference to value at the specified index

Safety

Undefined behavior if the index is out of bounds

pub fn start_ptr(&self) -> *mut T

Give a raw pointer to the start of the elements

pub fn middle_ptr(&self) -> *mut T

Give a raw pointer to the middle of the elements

pub fn end_ptr(&self) -> *mut T

pub fn split_at(&self, index: isize) -> (&[T], &[T])

pub fn clear(&mut self)

pub fn enumerate_back(&self) -> SignedEnumerate<Iter<'_, T>>

Enumerate the indices and values of the elements in the back of the vector.

The primary advantage over regular enumeration is that it gives proper negative indices since the elements are in the back.

pub fn enumerate_front(&self) -> SignedEnumerate<Iter<'_, T>>

Enumerate the indices and values of the elements in the front of the vector.

The only possible advantage over regular enumeration is that it gives positive isize indices for consistency with enumeration over the back.

pub fn enumerate(&self) -> SignedEnumerate<Iter<'_, T>>

Enumerate the indices and values of each element in the front and back.

The primary advantage over regular enumeration is that it gives proper negative indices for elements that are in the back.

pub fn enumerate_mut(&mut self) -> SignedEnumerate<IterMut<'_, T>>

Mutably enumerate the indices and values of each element in the front and back.

The primary advantage over regular enumeration is that it gives proper negative indices for elements that are in the back.

pub fn truncate_back(&mut self, len: usize)

pub fn truncate_front(&mut self, len: usize)

pub fn retain<F: FnMut(isize, &mut T) -> bool>(&mut self, pred: F)

pub fn retain_back<F: FnMut(isize, &mut T) -> bool>(&mut self, pred: F)

pub fn retain_front<F: FnMut(isize, &mut T) -> bool>(&mut self, pred: F)

pub fn drain_filter_back<F: FnMut(isize, &mut T) -> bool>( &mut self, pred: F, ) -> DrainFilterBack<'_, T, F>

pub fn drain_filter_front<F: FnMut(isize, &mut T) -> bool>( &mut self, pred: F, ) -> DrainFilterFront<'_, T, F>

Trait Implementations

impl<T: Clone> Clone for TwoSidedVec<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for TwoSidedVec<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Default for TwoSidedVec<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T> Drop for TwoSidedVec<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T> From<Vec<T>> for TwoSidedVec<T>

fn from(original: Vec<T>) -> Self

Converts to this type from the input type.

impl<T: Hash> Hash for TwoSidedVec<T>

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T, I: TwoSidedIndex<T>> Index<I> for TwoSidedVec<T>

type Output = <I as TwoSidedIndex<T>>::Output

The returned type after indexing.

fn index(&self, index: I) -> &I::Output

Performs the indexing (container[index]) operation.

impl<T, I: TwoSidedIndex<T>> IndexMut<I> for TwoSidedVec<T>

fn index_mut(&mut self, index: I) -> &mut I::Output

Performs the mutable indexing (container[index]) operation.

impl<T: PartialEq<U>, U> PartialEq<TwoSidedVec<U>> for TwoSidedVec<T>

fn eq(&self, other: &TwoSidedVec<U>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a, T: Copy + 'a> TwoSidedExtend<&'a T> for TwoSidedVec<T>

fn extend_back<I: IntoIterator<Item = &'a T>>(&mut self, iter: I)

fn extend_front<I: IntoIterator<Item = &'a T>>(&mut self, iter: I)

impl<T> TwoSidedExtend<T> for TwoSidedVec<T>

fn extend_back<I: IntoIterator<Item = T>>(&mut self, iter: I)

fn extend_front<I: IntoIterator<Item = T>>(&mut self, iter: I)

impl<T: Eq> Eq for TwoSidedVec<T>