RAII-managed temporary files and directories.

Example

{ TempDir } :: import "std/fs/temp";

main :: (fn(using(io : IO)) -> unit)({
  given(exn) : Exception = {
    throw : (fn(forall(T : Type), error: AnyError) -> T)(
      { println(error.to_string()); exit(i32(1)); }
    )
  };

  dir := io.await(TempDir.new());
  println(dir.path());
  io.await(dir.remove());
});