Crate format_bytes

This crate exposes a procedural macro that allows you to format bytestrings. For more background on why you would want to do that, read this article.

Usage

Add this to your Cargo.toml:

[dependencies]
format-bytes = "0.1"

then use the macro like so:

use format_bytes::format_bytes;

fn main() {
    assert_eq!(
        format_bytes!(b"look at those {} bytes", &[0u8, 1, 2]),
        b"look at those \x00\x01\x02 bytes"
    );
}

See more examples of how it works on the documentation of format_bytes! itself.

Missing features

• Named arguments, but they should be added in a future version
• Python-like “f-string” functionality is not planned because of its more complex implementation and limited actual benefit
• format!-like padding helpers: if the need manifests itself, they might appear

Why not 1.0?

Not until named arguments have landed and the macro gets a bit of mileage (it will be used in Mercurial).

Macros

format_bytes

Creates a Vec<u8> using interpolation of runtime expressions.

write_bytes

Like format_bytes!, but writes to a stream given as an additional first argument.

Structs

Utf8

Adaptor for types that implement std::fmt::Display. The Unicode output is encoded as UTF-8.

Traits

DisplayBytes

Let types decide how to format themselves for presentation to users in a byte-stream output.

Functions

join

Format a sequence of values with the given separator repeated between any two consecutive values, but not at the start or end of the sequence.