itoa
====
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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"
```
<br>
## Performance (lower is better)
<br>
## 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<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.
<br>
#### License
<sup>
Licensed under either of <a href="LICENSE-APACHE">Apache License, Version
2.0</a> or <a href="LICENSE-MIT">MIT license</a> at your option.
</sup>
<br>
<sub>
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.
</sub>