trigraph

Use trigraphs in rust:

use trigraph::trigraph;

trigraph! {
    const HELLO_WORLD: &??(u8??) = &??(0x48u8, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x57, 0x6f, 0x72, 0x6c, 0x64, 0x21??);
    fn main() ??<
        println!("??<??> nyaa??-", String::from_utf8_lossy(HELLO_WORLD));
    ??>
}

Limitations

This is mostly untested. Does not work with ??' since it interacts badly with the tokenizer because of the '. Does not work with differing delimiters like { with ??> or ??( with ].