crimes against Rust

war_crimes.rs

#![feature(macro_metavar_expr)]

macro_rules! repeat_2 {
    ($($what:tt)*) => {
        $($what)*
        $($what)*
    }
}

macro_rules! make_repeat_from {
    ($from:ident, $out:ident) => {
        macro_rules! $out {
            ($$($$what:tt)*) => {
                $from! { $$($$what)* }
                $from! { $$($$what)* }
            }
        }
    }
}

macro_rules! make_repeat {
    ($from:ident $out:ident $($rest:ident)*) => {
        make_repeat_from! { $from, $out }
        make_repeat! { $out $($rest)* }
    };

    ($last:ident) => {}
}

make_repeat! {
    repeat_2
    repeat_4
    repeat_8
    repeat_16
    repeat_32
    repeat_64
    repeat_128
    repeat_256
    repeat_512
    repeat_1024
    /* uncomment to hang everything
    repeat_2048
    repeat_4096
    repeat_8192
    repeat_16384
    repeat_32768
    repeat_65536
    */
}

fn main() {
    let mut i = 0;
    repeat_1024! {
        println!("hello {}", i);
        i += 1;
    }
}