# \[ANN\] Bitstring (and ppx\_bitstring) 4.0.0

**URL:** <https://discuss.ocaml.org/t/ann-bitstring-and-ppx-bitstring-4-0-0/6471>\
**Category:** Community\
**Tags:** announce\
**Created:** [September 22, 2020, 6:31am UTC](https://discuss.ocaml.org/t/ann-bitstring-and-ppx-bitstring-4-0-0/6471 "2020-09-22T06:31:14Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![xrguerin](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ocaml.org/xrguerin/32/2292_2.png) [@xrguerin](https://discuss.ocaml.org/u/xrguerin)\
**Post date:** [September 22, 2020, 6:31am UTC](https://discuss.ocaml.org/t/ann-bitstring-and-ppx-bitstring-4-0-0/6471/1 "2020-09-22T06:31:14Z")

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**Features**

- Add support for let bindings introduced in 4.08
- Switch to PPXLIB

**Deprecations**

As PPXLIB requires `ocaml >= 4.04` support for earlier versions has been dropped.

**Breaking changes**

This release splits the library from the PPX to reduce runtime dependencies. Projects using the PPX from bitstring will need to also depends on ppx\_bitstring from now on.

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**Author:** ![rgrinberg](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ocaml.org/rgrinberg/32/40_2.png) [@rgrinberg](https://discuss.ocaml.org/u/rgrinberg)\
**Post date:** [September 22, 2020, 7:02am UTC](https://discuss.ocaml.org/t/ann-bitstring-and-ppx-bitstring-4-0-0/6471/2 "2020-09-22T07:02:32Z")

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The project is hosted [here](https://github.com/xguerin/bitstring) for those who are interested.There’s also some excellent [docs](https://bitstring.software/documentation/)