Struct mz_repr::adt::jsonb::vec_stack::VecStack

pub struct VecStack<'a, T> {
    buf: &'a mut Vec<T>,
    i: usize,
}

A VecStack presents as a stack of Vecs where only the vector at the top of the stack is accessible. It is backed by a single Vec whose allocation is reused as elements are added to and dropped from the stack, and so it can be more efficient than allocating individual vectors.

Fields

buf: &'a mut Vec<T>

i: usize

Implementations

impl<'a, T> VecStack<'a, T>

pub fn new(buf: &'a mut Vec<T>) -> VecStack<'a, T>

Creates a new VecStack backed by buf.

The stack starts with a single psuedo-vector.

pub fn push(&mut self, t: T)

Adds a new element to the psuedo-vector at the top of the stack.

pub fn sort_by_key<F, K>(&mut self, f: F)

where F: FnMut(&T) -> K, K: Ord,

Sorts the psuedo-vector at the top of the stack by the key identified by f.

pub fn len(&self) -> usize

Returns the length of the psuedo-vector at the top of the stack.

pub fn fresh<'b>(&'b mut self) -> VecStack<'b, T>

Push a fresh vector onto the stack.

The returned VecStack is a handle to this vector. The psuedo-vector beneath the new vector is inaccessible until the new handle is dropped.

Trait Implementations

impl<'a, T> Drop for VecStack<'a, T>

fn drop(&mut self)

Executes the destructor for this type.

impl<'a, T> Index<usize> for VecStack<'a, T>

type Output = T

The returned type after indexing.

fn index(&self, i: usize) -> &Self::Output

Performs the indexing (container[index]) operation.