Crate numtoa

The standard library provides a convenient method of converting numbers into strings, but these strings are heap-allocated. If you have an application which needs to convert large volumes of numbers into strings, but don't want to pay the price of heap allocation, this crate provides an efficient no_std-compatible method of heaplessly converting numbers into their string representations, storing the representation within a reusable byte array.

In addition to supporting the standard base 10 conversion, this implementation allows you to select the base of your choice. Therefore, if you want a binary representation, set the base to 2. If you want hexadecimal, set the base to 16.

Base 10 Example

use numtoa::NumToA;
use std::io::{self, Write};

let stdout = io::stdout();
let mut stdout = stdout.lock();
let mut buffer = [0u8; 20];

let number: u32 = 162392;
let mut bytes_written = number.numtoa(10, &mut buffer);
let _ = stdout.write(&buffer[0..bytes_written]);
let _ = stdout.write(b"\n");
assert_eq!(&buffer[0..bytes_written], "162392".as_bytes());

let other_number: i32 = -6235;
bytes_written = other_number.numtoa(10, &mut buffer);
let _ = stdout.write(&buffer[0..bytes_written]);
let _ = stdout.write(b"\n");
assert_eq!(&buffer[0..bytes_written], "-6235".as_bytes());

let large_num: u64 = 35320842;
bytes_written = large_num.numtoa(10, &mut buffer);
let _ = stdout.write(&buffer[0..bytes_written]);
let _ = stdout.write(b"\n");
assert_eq!(&buffer[0..bytes_written], "35320842".as_bytes());

let max_u64: u64 = 18446744073709551615;
bytes_written = max_u64.numtoa(10, &mut buffer);
let _ = stdout.write(&buffer[0..bytes_written]);
let _ = stdout.write(b"\n");
assert_eq!(&buffer[0..bytes_written], "18446744073709551615".as_bytes());

Traits

NumToA

Converts a number into a string representation, storing the conversion into a mutable byte slice.