Constime

<h1 align="center"> constime </h1> <p align="center"> Zig's <code>comptime</code> for Rust, with zero dependencies. </p> <div align="center"> <a href="https://github.com/DvvCz/constime/actions"> <img alt="GitHub Actions Workflow Status" src="https://img.shields.io/github/actions/workflow/status/DvvCz/constime/ci.yml?label=build"> </a> <a href="https://crates.io/crates/constime"> <img alt="Crates.io Version" src="https://img.shields.io/crates/v/constime"> </a> <a href="https://github.com/DvvCz/constime/releases/latest"> <img alt="GitHub Release" src="https://img.shields.io/github/v/release/DvvCz/constime"> </a> </div>

Usage

cargo add constime

Dependencies in comptime! can be stored in either [dependencies] or [build-dependencies].

If you use build dependencies, you will need to explicitly link with extern crate and a build.rs file to force them to compile.

Example

fn main() {
	use constime::comptime;

	// Let's use a pure-build time dependency
	println!("Here's a fact about the number 5: {}", comptime! {
		extern crate ureq;

		ureq::get("http://numbersapi.com/5/math")
			.call()
			.unwrap()
			.into_string()
			.unwrap()
	});

	// Standard library works fine too.
	println!(
		"Compiled {} seconds after unix epoch.",
		comptime! {
			std::time::SystemTime::now()
				.duration_since(std::time::UNIX_EPOCH)
				.expect("Time went backwards")
				.as_secs()
		}
	);
}

Note

You should get autocomplete and error feedback when using the macro.

This by creating temporary binaries running each of your constime! invocations, stored in std::env::temp_dir().join("constime").join(<crate name>)