1 unstable release

0.1.0 May 30, 2023

#395 in No standard library

34 downloads per month
Used in push_decode

MITNFA license

794 lines

Lightweight generic IO

Less error-prone, no_std IO traits generic over their error types.

This is a simplified version of genio containing only buffered traits.

Advantages over std

  • no_std - doesn't require an operating system
  • Error being associated type is more flexible
  • Less error-prone - no read and write methods which are often mistaken for read_all or write_all

Advantages over genio

  • Simpler
  • Less unsafe to deal with uninitialized bytes (currently none, may change in the future)
  • Most uses of IO need some buffering anyway
  • Less error-prone - no read and write methods which are often mistaken for read_all or write_all
  • No FlushError makes error handling simpler

Target audience

Mainly serialization libraries and their consumers. Can be also usful for simple protocols that don't need precise control of read and write calls.

Probably should not be used in lower layers.

Usage overview

The BufRead trait is very similar to the one from std. The biggest differences are error type and lack of error-prone read method. Since it is implemented on std::io::BufReader and primitive std types you can use it exactly the same as std::io::BufRead in most cases. There's an added benefit that you can statically prove reading from &[u8] will not fail (but it can return UnexpectedEnd).

Similarly, BufWrite is just std::io::Write with error being associated and missing write method. It still requires that writing is either buffered or fast because that's what most encoders need.


  • std - integration with the standard library: implementations and adapters
  • alloc - additional features requiring allocation


The crate intends to have conservative MSRV and only bump it when it provides significant benefit and at most to the version available in latest Debian stable. Currently tested MSRV is 1.41.1 (Debian oldstable) but due to its simplicity it's possible it works on even lower versions.

Some features may be only available in newer Rust versions. Thus it is recommended to use recent Rust if possible.

No runtime deps