commit | d1e26a1cd1f3c5ef337ac302db4180390c6bf0df | [log] [tgz] |
---|---|---|
author | Linux Build Service Account <lnxbuild@localhost> | Wed Jan 26 00:33:15 2022 -0800 |
committer | Linux Build Service Account <lnxbuild@localhost> | Wed Jan 26 00:33:15 2022 -0800 |
tree | b00fd7be46bb83f62f7851d8789a7e988c165bba | |
parent | d7657438fdc42efee164c745e6c9294efd6377e8 [diff] | |
parent | 63784f2f5b191ccb84d60dd234c2d06626a98740 [diff] |
Merge 63784f2f5b191ccb84d60dd234c2d06626a98740 on remote branch Change-Id: I1ffb6a23aa5d57fe2d436163c6d8b856b6ba24d2
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.