itoa

This crate provides fast functions for printing integer primitives to an io::Write. The implementation comes straight from libcore but avoids the performance penalty of going through fmt::Formatter.

See also dtoa for printing floating point primitives.

Performance (lower is better)

performance

Functions

extern crate itoa;

// write to a vector or other io::Write
let mut buf = Vec::new();
itoa::write(&mut buf, 128u64)?;
println!("{:?}", buf);

// write to a stack buffer
let mut bytes = [b'\0'; 20];
let n = itoa::write(&mut bytes[..], 128u64)?;
println!("{:?}", &bytes[..n]);

The function signature is:

fn write<W: io::Write, V: itoa::Integer>(writer: W, value: V) -> io::Result<usize>

where itoa::Integer is implemented for i8, u8, i16, u16, i32, u32, i64, u64, i128, u128, isize and usize. 128-bit integer support is only available with the nightly compiler when the i128 feature is enabled for this crate. The return value gives the number of bytes written.

Dependency

Itoa is available on crates.io. Use the following in Cargo.toml:

[dependencies]
itoa = "0.3"

License

Licensed under either of

Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution