Macro const_join 

macro_rules! const_join {
    ($array:expr, $sep:expr) => { ... };
}

Returns a new constant value with the joined string of array and sep. Example usage:

const FLAGS: &'static str = const_str_join::const_join!(["--help", "--version", "--verbose"], "|");
const HELP: &'static str = const_str_join::const_join!(["flags:", FLAGS], " ");
assert_eq!(HELP, "flags: --help|--version|--verbose");