pcg_rand
========
[](https://crates.io/crates/pcg_rand)
[](https://docs.rs/pcg_rand/)
[](https://travis-ci.com/robojeb/pcg_rand)
[](https://github.com/robojeb/pcg_rand/blob/master/LICENSE)
[](https://github.com/robojeb/pcg_rand)
To use this library add the following to your `Cargo.toml`
```
pcg_rand = "0.13.0"
```
PCG stands for Permuted Congruential generators. They are a simple family of
random number generators which use the much denounced Linear Congruential
Generator as a base. To overcome the well known limitations of the LCG Generator
the PCG family utilizes permutation functions to permute the output. More
information about PCG can be found [here](http://pcg-random.org).
Current Status
--------------
This library currently provides 32 and 64 bit generators.
It provides the major "stream" types, including the unique stream which is determined
by their current location in memory.
Future Work
-----------
* Implement seeking for the generators
Changes
-------
* (6/8/2016): Added support for extended generators. This implementation
is based on my understanding of how the extension is specified in the paper.
I would love a code review on the implementation. I don't think that this
particular implementation is the same as the implementation in the C++ version
of PCG.
* (6/7/2016): Added back some of the macros which got removed in 0.5.0
This is in an effort to improve some performance. Hopefully associated constants
can help us remove these again, but for now removing the PcgConsts trait gives
some extra performance and reduces indirection. It also means that it is now
easier to implement new streams and multipliers because you aren't bound
to using the three things in PcgConsts.
* (7/31/2018): Remembered to update the README (including changelog). Migrated
to using the `rand: 0.5` crate which involves new methods. Most of the functions
are now not based on macro's but instead are fully generic and utilize the
`num-traits` wrapping traits as needed. Additionally the crate now has support
for using the native `u128` since that is stable in Rust now. This pushes the
minimum Rust version to 1.26.
* (8/2/2018): Provided better defaults for the `new_unseeded` function so that
it can be useful for testing. Improved the docs to suggest seeding and updated
the documentation examples to use `from_entropy` instead of `new_unseeded` to
promote good use of the generators.
* (10/15/2018): Added cargo features for `u128` and experimental `serde1`
support. Also fixed an issue in `0.9.2` which caused it to be nightly only
(oops). Started migrating benchmarks to critereon.
* (12/4/2018): Upgraded to `rand 0.6` and `rand_core 0.3`. Fixed an issue where
tests wouldn't run if there was no `u128` support. Serde support is still
highly experimental.
* (12/12/2018): Bump to 0.10.1 to include the CI build badge on crates.io
* (10/24/2019): Bump to 0.11.0 to use `rand 0.7` and `rand_core 0.5`
* (10/28/2019): Bump to 0.11.1. Added the ability to make generators output a
a permutation of their entire internal state.
* (10/02/2020): Update to 0.13.0. Added the ability to extract the internal
state of the generator. Moved the examples from `bin` to `examples` for
better discovery. Changed the serialization derivation, it only makes sense
to deserialize into a `SetSeq` type so it is the only one which supports
deserialization. The serialization step writes out the internal state as
an array and does not record any information about the type of generator.
* (10/12/2020): Added the DXsM output and made it the default (this is the
specified intention of the C++ library author). Re-worked serialization to
create a definition structure which contains all the information needed to
verify that the PCG you are serializing into/out-of is compatible with the
stored information. This can be disabled with the `no_deserialize_verify`
feature.