import std::print; import std::from_str; import std::add_char; import std::set_char; import std::free_string; import std::new_string; import std::add_num_to_str; import std::concat_strings; fn main() -> u8 { let mut test = from_str("hello"); concat_strings(&mut test, from_str(" world")); add_char(&mut test, '!'); add_char(&mut test, '\n'); add_num_to_str(&mut test, 175); print(test); free_string(&test); return addition(5, 3); }