# UNSIGNED_VARINT
Core Features
Encoding/Decoding:
Encode u32, u64, u128 to varint bytes
Decode varint bytes back to integers
Handle both owned (Vec<u8>) and borrowed (&[u8]) data
Return number of bytes written/read
Error Handling:
Detect buffer overflow (not enough space to encode)
Detect truncated data (incomplete varint)
Detect overflow (varint too large for target type)
Clear error types, not just Result<T, ()>
Zero-Copy Operations:
Read from byte slices without allocation
Write to pre-allocated buffers
std::io::Read and std::io::Write trait implementations
Important Features
Performance:
Inline functions for hot paths
Benchmarks comparing to existing libraries
Optional SIMD optimizations for batch operations
#[no_std] support for embedded systems
Ergonomics:
Trait-based API (e.g., VarIntEncode, VarIntDecode)
Helper functions like encoded_len(value) to predict size
Builder pattern for configuration if needed
Good type inference support
Compatibility:
Support multiple varint formats (LEB128, Protocol Buffers, etc.)
Feature flags for different encodings
Async I/O support (tokio::AsyncRead/AsyncWrite)
Nice-to-Have Features
Advanced:
Streaming decoder for parsing continuous streams
Batch encoding/decoding APIs
serde support for serialization frameworks
Zero-allocation iterators over varint sequences
Const functions where possible (for compile-time encoding)
Developer Experience:
Comprehensive examples in docs
Comparison guide with other libraries
Migration guide if competing with existing crates
Clear performance characteristics documented