commit | 5c60eb216f3c14f6e4a2124542094ee67611e888 | [log] [tgz] |
---|---|---|
author | Yi Kong <yikong@google.com> | Tue Sep 01 04:52:53 2020 +0000 |
committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Tue Sep 01 04:52:53 2020 +0000 |
tree | d9b0fa6e8495b377dba489f40030156dd22347dc | |
parent | fdcd4948cf0f4dcf61cf26322684b1569c38739c [diff] | |
parent | 217168306af7761a595a09a6c826038910e98ca6 [diff] |
Import 'itoa' crate version 0.4.6 am: 8884bbeb9c am: aa38c62a6a am: ac1a7b3d82 am: 262d642d67 am: 6bfb67ddcb am: 217168306a Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/itoa/+/1414792 Change-Id: If5a413b60cec3437aae142e4c15e785eb2d67bd5
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.