Crate constcat

std::concat! with support for const variables and expressions.

Works on stable Rust ✨.

🚀 Getting started

Add constcat to your Cargo manifest.

cargo add constcat

Import the macro using the following.

use constcat::concat;

🤸 Usage

concat! works exactly like std::concat! except you can now pass variables and constant expressions. For example:

const CRATE_NAME: &str = env!("CARGO_PKG_NAME");
const CRATE_VERSION: &str = env!("CARGO_PKG_VERSION");
const fn tada() -> &'static str { "🎉" }
const VERSION: &str = concat!(CRATE_NAME, " ", CRATE_VERSION, tada());

concat_bytes! works similarly except it yields a static byte slice. For example:

const VERSION: u32 = 1;
const fn entries() -> &'static [u8] { b"example" }
const HEADER: &[u8] = concat_bytes!(&VERSION.to_le_bytes(), entries());

Macros

• concat
  Concatenate const &str expressions and literals into a static string slice.
• concat_bytes
  Concatenate const &[u8] expressions and literals into a static byte slice.
• concat_slices
  Concatenate const &[T] expressions into a static slice.