vendor/itoa/README.md

   1 itoa
   2 ====
   3
   4 [![Build Status](https://api.travis-ci.org/dtolnay/itoa.svg?branch=master)](https://travis-ci.org/dtolnay/itoa)
   5 [![Latest Version](https://img.shields.io/crates/v/itoa.svg)](https://crates.io/crates/itoa)
   6 [![Rust Documentation](https://img.shields.io/badge/api-rustdoc-blue.svg)](https://docs.rs/itoa)
   7
   8 This crate provides fast functions for printing integer primitives to an
   9 [`io::Write`] or a [`fmt::Write`]. The implementation comes straight from
  10 [libcore] but avoids the performance penalty of going through
  11 [`fmt::Formatter`].
  12
  13 See also [`dtoa`] for printing floating point primitives.
  14
  15 *Version requirement: rustc 1.0+*
  16
  17 [`io::Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
  18 [`fmt::Write`]: https://doc.rust-lang.org/core/fmt/trait.Write.html
  19 [libcore]: https://github.com/rust-lang/rust/blob/b8214dc6c6fc20d0a660fb5700dca9ebf51ebe89/src/libcore/fmt/num.rs#L201-L254
  20 [`fmt::Formatter`]: https://doc.rust-lang.org/std/fmt/struct.Formatter.html
  21 [`dtoa`]: https://github.com/dtolnay/dtoa
  22
  23 ```toml
  24 [dependencies]
  25 itoa = "0.4"
  26 ```
  27
  28 <br>
  29
  30 ## Performance (lower is better)
  31
  32 ![performance](https://raw.githubusercontent.com/dtolnay/itoa/master/performance.png)
  33
  34 <br>
  35
  36 ## Examples
  37
  38 ```rust
  39 use std::{fmt, io};
  40
  41 fn demo_itoa_write() -> io::Result<()> {
  42     // Write to a vector or other io::Write.
  43     let mut buf = Vec::new();
  44     itoa::write(&mut buf, 128u64)?;
  45     println!("{:?}", buf);
  46
  47     // Write to a stack buffer.
  48     let mut bytes = [0u8; 20];
  49     let n = itoa::write(&mut bytes[..], 128u64)?;
  50     println!("{:?}", &bytes[..n]);
  51
  52     Ok(())
  53 }
  54
  55 fn demo_itoa_fmt() -> fmt::Result {
  56     // Write to a string.
  57     let mut s = String::new();
  58     itoa::fmt(&mut s, 128u64)?;
  59     println!("{}", s);
  60
  61     Ok(())
  62 }
  63 ```
  64
  65 The function signatures are:
  66
  67 ```rust
  68 fn write<W: io::Write, V: itoa::Integer>(writer: W, value: V) -> io::Result<usize>;
  69
  70 fn fmt<W: fmt::Write, V: itoa::Integer>(writer: W, value: V) -> fmt::Result;
  71 ```
  72
  73 where `itoa::Integer` is implemented for i8, u8, i16, u16, i32, u32, i64, u64,
  74 i128, u128, isize and usize. 128-bit integer support requires rustc 1.26+ and
  75 the `i128` feature of this crate enabled.
  76
  77 The `write` function is only available when the `std` feature is enabled
  78 (default is enabled). The return value gives the number of bytes written.
  79
  80 <br>
  81
  82 #### License
  83
  84 <sup>
  85 Licensed under either of <a href="LICENSE-APACHE">Apache License, Version
  86 2.0</a> or <a href="LICENSE-MIT">MIT license</a> at your option.
  87 </sup>
  88
  89 <br>
  90
  91 <sub>
  92 Unless you explicitly state otherwise, any contribution intentionally submitted
  93 for inclusion in this crate by you, as defined in the Apache-2.0 license, shall
  94 be dual licensed as above, without any additional terms or conditions.
  95 </sub>