itoa ==== [![Build Status](https://api.travis-ci.org/dtolnay/itoa.svg?branch=master)](https://travis-ci.org/dtolnay/itoa) [![Latest Version](https://img.shields.io/crates/v/itoa.svg)](https://crates.io/crates/itoa) [![Rust Documentation](https://img.shields.io/badge/api-rustdoc-blue.svg)](https://docs.rs/itoa) 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+* [`io::Write`]: https://doc.rust-lang.org/std/io/trait.Write.html [`fmt::Write`]: https://doc.rust-lang.org/core/fmt/trait.Write.html [libcore]: https://github.com/rust-lang/rust/blob/b8214dc6c6fc20d0a660fb5700dca9ebf51ebe89/src/libcore/fmt/num.rs#L201-L254 [`fmt::Formatter`]: https://doc.rust-lang.org/std/fmt/struct.Formatter.html [`dtoa`]: https://github.com/dtolnay/dtoa ```toml [dependencies] itoa = "0.4" ```
## Performance (lower is better) ![performance](https://raw.githubusercontent.com/dtolnay/itoa/master/performance.png)
## Examples ```rust 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: ```rust fn write(writer: W, value: V) -> io::Result; fn fmt(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.
#### License Licensed under either of Apache License, Version 2.0 or MIT license at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.