types - Converting number primitives (i32, f64, etc) to byte representations

Question

I am writing a library that encodes/decodes data to/from a binary format. Part of the format is numbers, which I'm using Rust's native primitive types for (like i8, i64, f32 etc.).

Is there an easy, built-in way to convert these data types into/from binary, i.e. convert a f64/f32/i64/etc. into a Vec<u8>? Likewise is there a way to convert 4 u8s (in a Vec<u8> say) into an f32?

Answer 1

As of Rust 1.32 you can use {to,from}_{ne,le,be}_bytes for integral types.

let begin = 1234_i32;
let bytes = begin.to_ne_bytes();
let and_back = i32::from_ne_bytes(bytes);

For floating point you still have to rely on prior methods.