fashex - fast hexadecimal string formatting

Hexadecimal string encoding and decoding with best-effort SIMD acceleration.

Highlights

• Precise public APIs (encode or decode).
• Best-effort SIMD acceleration.
• APIs that works in const contexts.
• Unlike crates const-hex, faster-hex, etc., this crate does not require initialization of the output buffer.

Disclaimer

Although all tests are passing and hours of fuzzing show no failures, latent bugs may still exist in the code.

1. The SIMD-accelerated code paths for x86 / x86_64 architecture are well tested and fuzzed.
2. The SIMD-accelerated code paths for aarch64 architecture are tested and fuzzed.
3. The SIMD-accelerated code paths for loongarch64 architecture have not been tested or fuzzed on real hardware.

If you find any bugs, please report them.

Acknowledgements

This crate is highly inspired by the following repositories:

• const-hex, SPDX-License-Identifier: MIT OR Apache-2.0
• faster-hex, SPDX-License-Identifier: MIT OR Apache-2.0
• hex-simd, SPDX-License-Identifier: MIT

License