---

yaml
---
r: 132037
b: refs/heads/dist-snap
c: 4574b2f
h: refs/heads/master
i:
  132035: 4826ec0
v: v3

Author: treeman

[refs]

@@ -6,7 +6,7 @@ refs/heads/try: 457a3c991d79b971be07fce75f9d0c12848fb37c
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
 refs/heads/try2: 147ecfdd8221e4a4d4e090486829a06da1e0ca3c
-refs/heads/dist-snap: 26047f15e5f1db33d66979554c29fba3cf4d2c33
+refs/heads/dist-snap: 4574b2fbaa866fbe73224f57981151aab1f1f15b
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503
 refs/heads/try3: 9387340aab40a73e8424c48fd42f0c521a4875c0

branches/dist-snap/src/libcollections/bitv.rs

@@ -8,6 +8,55 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+//! Collections implemented with bit vectors.
+//!
+//! # Example
+//!
+//! This is a simple example of the [Sieve of Eratosthenes][sieve]
+//! which calculates prime numbers up to a given limit.
+//!
+//! [sieve]: http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
+//!
+//! ```
+//! use std::collections::{BitvSet, Bitv};
+//! use std::iter;
+//!
+//! let max_prime = 10000;
+//!
+//! // Store the primes as a BitvSet
+//! let primes = {
+//!     let mut bv = Bitv::with_capacity(max_prime, true);
+//!
+//!     // Neither 0 nor 1 are prime
+//!     bv.set(0, false);
+//!     bv.set(1, false);
+//!
+//!     for i in range(2, max_prime) {
+//!         // if i is a prime
+//!         if bv.get(i) {
+//!             // mark all multiples of i as non-prime (any multiples below i * i
+//!             // will have been marked as non-prime previously)
+//!             for j in iter::range_step(i * i, max_prime, i) { bv.set(j, false) }
+//!         }
+//!     }
+//!     BitvSet::from_bitv(bv)
+//! };
+//!
+//! // Simple primality tests below our max bound
+//! let print_primes = 20;
+//! print!("The primes below {} are: ", print_primes);
+//! for x in range(0, print_primes) {
+//!     if primes.contains(&x) {
+//!         print!("{} ", x);
+//!     }
+//! }
+//! println!("");
+//!
+//! // We can manipulate the internal Bitv
+//! let num_primes = primes.get_ref().iter().filter(|x| *x).count();
+//! println!("There are {} primes below {}", num_primes, max_prime);
+//! ```
+
 #![allow(missing_doc)]
 
 use core::prelude::*;