antlion

A magical meta function that evaluate (at compile-time if used inside a macro which is the point of taking a TokenStream input) any Rust expr!

use antlion::Sandbox;
use quote::quote;

let test = Sandbox::new().unwrap();
let x: u32 = test.eval(quote! { 2 + 2 }).unwrap();
assert!(x == 4);

This library indeed is not what would benefit the most your crate build time, but it was still design in mind with the will of caching sandbox compilation.