| commit | f3698df10fcb3defcbe50b7c9c3a567cbf19fac9 | [log] [tgz] |
|---|---|---|
| author | Android Build Coastguard Worker <[email protected]> | Tue May 10 07:06:49 2022 +0000 |
| committer | Android Build Coastguard Worker <[email protected]> | Tue May 10 07:06:49 2022 +0000 |
| tree | 3b1504f99e3af24d7ff3099804413156a07ffab5 | |
| parent | 3d7279c7b3973433ce44028a3cad8801cc727586 [diff] | |
| parent | a3c757545f3449a212d1f23b39a87b8e04d88360 [diff] |
Snap for 8564071 from a3c757545f3449a212d1f23b39a87b8e04d88360 to mainline-conscrypt-release Change-Id: I412f9cca008fe3a912db64c843ababd19e0c8c04
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.