commit | b6883b3b87ae731cdb513310d64f3ea771c8afb5 | [log] [tgz] |
---|---|---|
author | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Mon Dec 20 11:04:40 2021 +0000 |
committer | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Mon Dec 20 11:04:40 2021 +0000 |
tree | a37d77a527c577f11a2c00f84694c9fd47b5617b | |
parent | c69bef84aedd1242ed637501db37eb86ff8bab06 [diff] | |
parent | 011d805a61cf0d8c148b125c92187ef3f9b3ba03 [diff] |
Snap for 8014993 from 011d805a61cf0d8c148b125c92187ef3f9b3ba03 to s-keystone-qcom-release Change-Id: I49cac07b1020a2e81d6cfdc08f2226f653401a48
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.