commit | 4d605cb2b78cd79932e5bf3eb248e95d141f14be | [log] [tgz] |
---|---|---|
author | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Sat Oct 30 03:05:41 2021 +0000 |
committer | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Sat Oct 30 03:05:41 2021 +0000 |
tree | b00fd7be46bb83f62f7851d8789a7e988c165bba | |
parent | e8c179cbf892ebcf97a8832f45be190ebb45ead7 [diff] | |
parent | 4b0cd3dc44f22fa6cda84c84ec4d58fd1898a94f [diff] |
Snap for 7868516 from 4b0cd3dc44f22fa6cda84c84ec4d58fd1898a94f to tm-release Change-Id: I529c6f4d3f799b923bfa82c3ae643e1087badb44
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.