# Crate packedvec[−][src]

## Expand description

## Structs

A `PackedVec`

stores vectors of integers efficiently while providing
an API similar to `Vec`

. The basic idea is to store each element using the minimum number of
bits needed to represent every element in the `Vec`

. For example, if we have a `Vec<u64>`

with
elements [20, 30, 140], every element wastes most of its 64 bits: 7 bits is sufficient to
represent the range of elements in the vector. Given this input vector, `PackedVec`

stores each
elements using exactly 7 bits, saving substantial memory. For vectors which often contain small
ranges of numbers, and which are created rarely, but read from frequently, this can be a
significant memory and performance win.