commit | b6d00fbc3e189a6a9fff4160c3fd208e8378ae8b | [log] [tgz] |
---|---|---|
author | Android Build Coastguard Worker <[email protected]> | Wed Mar 23 22:53:40 2022 +0000 |
committer | Android Build Coastguard Worker <[email protected]> | Wed Mar 23 22:53:40 2022 +0000 |
tree | a37d77a527c577f11a2c00f84694c9fd47b5617b | |
parent | a3c757545f3449a212d1f23b39a87b8e04d88360 [diff] | |
parent | 3d7279c7b3973433ce44028a3cad8801cc727586 [diff] |
Snap for 8347268 from 3d7279c7b3973433ce44028a3cad8801cc727586 to mainline-go-ipsec-release Change-Id: Ia8f6eae48beb793ffd3974cdebcbd0413e72fed2
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.