commit	e762e87b1c814e200ca91a2df8dd06098df5fc74	[log] [tgz]
author	Chih-Hung Hsieh <chh@google.com>	Mon Oct 12 11:10:34 2020 +0000
committer	Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>	Mon Oct 12 11:10:34 2020 +0000
tree	10c0471b78971f94c4027fd815f064d241dd8adf
parent	217168306af7761a595a09a6c826038910e98ca6 [diff]
parent	7a6689d6534d0f462203d74a18b68771e69e7bc1 [diff]

tree: 10c0471b78971f94c4027fd815f064d241dd8adf

README.md

itoa

This crate provides fast functions for printing integer primitives to an io::Write or a fmt::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.

Version requirement: rustc 1.0+

[dependencies]
itoa = "0.4"

Performance (lower is better)

performance

Examples

use std::{fmt, io};

fn demo_itoa_write() -> io::Result<()> {
    // 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 = [0u8; 20];
    let n = itoa::write(&mut bytes[..], 128u64)?;
    println!("{:?}", &bytes[..n]);

    Ok(())
}

fn demo_itoa_fmt() -> fmt::Result {
    // Write to a string.
    let mut s = String::new();
    itoa::fmt(&mut s, 128u64)?;
    println!("{}", s);

    Ok(())
}

The function signatures are:

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

fn fmt<W: fmt::Write, V: itoa::Integer>(writer: W, value: V) -> fmt::Result;

where itoa::Integer is implemented for i8, u8, i16, u16, i32, u32, i64, u64, i128, u128, isize and usize. 128-bit integer support requires rustc 1.26+ and the i128 feature of this crate enabled.

The write function is only available when the std feature is enabled (default is enabled). The return value gives the number of bytes written.

itoa

Performance (lower is better)

Examples

License