commit | 15f9f2fefdc0287ab07e3b51e6bdb2505a0619f9 | [log] [tgz] |
---|---|---|
author | android-build-team Robot <android-build-team-robot@google.com> | Wed Nov 25 02:54:57 2020 +0000 |
committer | android-build-team Robot <android-build-team-robot@google.com> | Wed Nov 25 02:54:57 2020 +0000 |
tree | 10c0471b78971f94c4027fd815f064d241dd8adf | |
parent | 2033998847797bdbaa0adf4d15a6b38a012c047e [diff] | |
parent | 3dbf0b5f073376a7afe1ca86646e942390098ae6 [diff] |
Snap for 6993940 from 3dbf0b5f073376a7afe1ca86646e942390098ae6 to sc-d1-release Change-Id: I07e4a6949beae3b55219204935fe3a6ed64dd9f4
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.