commit | e762e87b1c814e200ca91a2df8dd06098df5fc74 | [log] [tgz] |
---|---|---|
author | Chih-Hung Hsieh <chh@google.com> | Mon Oct 12 11:10:34 2020 +0000 |
committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Mon Oct 12 11:10:34 2020 +0000 |
tree | 10c0471b78971f94c4027fd815f064d241dd8adf | |
parent | 217168306af7761a595a09a6c826038910e98ca6 [diff] | |
parent | 7a6689d6534d0f462203d74a18b68771e69e7bc1 [diff] |
Copy description from Cargo.toml to METADATA am: fd17487e5f am: 25856d98bf am: 9f4182ba80 am: 7a6689d653 Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/itoa/+/1457135 Change-Id: Ide1f1d05c50a17398c25375d1e296e55960de1bb
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.