This crate provides a fast conversion of integer primitives to decimal strings. The implementation comes straight from libcore but avoids the performance penalty of going through core::fmt::Formatter.

See also zmij for printing floating point primitives.

[dependencies]
itoa = "1.0"

fn main() {
    let mut buffer = itoa::Buffer::new();
    let printed = buffer.format(128u64);
    assert_eq!(printed, "128");
}

The itoa-benchmark compares this library and other Rust integer formatting implementations across a range of integer sizes. The vertical axis in this chart shows nanoseconds taken by a single execution of itoa::Buffer::new().format(value) so a lower result indicates a faster library.