commit | f240b0341c5287433daef62df17e7eafd1e14ee7 | [log] [tgz] |
---|---|---|
author | android-build-team Robot <android-build-team-robot@google.com> | Sun Feb 21 00:05:36 2021 +0000 |
committer | android-build-team Robot <android-build-team-robot@google.com> | Sun Feb 21 00:05:36 2021 +0000 |
tree | 8deaebfc1ab9a7bc9d72e464f128e72c9d84e7e2 | |
parent | 3451b1e7eed5ae18ddeed89e57c60088bfef882b [diff] | |
parent | 0e7fa2b872acfb15f460a69b86de05a7dcd77539 [diff] |
Snap for 7160059 from 0e7fa2b872acfb15f460a69b86de05a7dcd77539 to sc-v2-release Change-Id: I01fce7709be1b224f5447a3b783bbbdf2c3aed1d
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"
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.