commit | 80a2c5b7f6593c77f8e86c01b16a3577fe26a174 | [log] [tgz] |
---|---|---|
author | Linux Build Service Account <lnxbuild@localhost> | Wed Jun 09 02:59:31 2021 -0700 |
committer | Linux Build Service Account <lnxbuild@localhost> | Wed Jun 09 02:59:31 2021 -0700 |
tree | a37d77a527c577f11a2c00f84694c9fd47b5617b | |
parent | 09e04cbe2061aa8a93d86ce92abf4a2b8cedd6f5 [diff] | |
parent | c69bef84aedd1242ed637501db37eb86ff8bab06 [diff] |
Merge c69bef84aedd1242ed637501db37eb86ff8bab06 on remote branch Change-Id: I80f6f096893b763b8a63ef8c30367f86e681983a
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.