sqlite3 Rust bindings, subtle problem with `&const <T>`

build.errors.log

$ git rebase -i to_rust4~4
Successfully rebased and updated refs/heads/to_rust4.
kunix:rustsqlite $ rustc --test sqlite.rc 
sqlite.rs:605:31: 605:42 error: mismatched types: expected `&const <V88>` but found `sqlite_bind_arg` (expected &-ptr but found enum sqlite_bind_arg)
sqlite.rs:605         assert x.get(~"id") == integer(2);
                                             ^~~~~~~~~~~
sqlite.rs:606:31: 606:42 error: mismatched types: expected `&const <V179>` but found `sqlite_bind_arg` (expected &-ptr but found enum sqlite_bind_arg)
sqlite.rs:606         assert x.get(~"k")  == text(~"e");
                                             ^~~~~~~~~~~
sqlite.rs:607:31: 607:44 error: mismatched types: expected `&const <V270>` but found `sqlite_bind_arg` (expected &-ptr but found enum sqlite_bind_arg)
sqlite.rs:607         assert x.get(~"v")  == number(2.17);
                                             ^~~~~~~~~~~~~
sqlite.rs:605:15: 605:42 error: cannot determine a type for this bounded type parameter: unconstrained type
sqlite.rs:605         assert x.get(~"id") == integer(2);
                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~

sqlite-excerpts.rs

enum sqlite_bind_arg {
  text(~str),
  number(float),
  integer(int),
  blob(~[u8]),
  null(),
}

...

  #[test]
  fn step_row_basics() {
    let dbh = checked_open();
    checked_exec(dbh,
      ~"
      BEGIN;
      CREATE TABLE IF NOT EXISTS test (id INTEGER, k TEXT, v REAL);
      INSERT OR IGNORE INTO test (id, k, v) VALUES(1, 'pi', 3.1415);
      INSERT OR IGNORE INTO test (id, k, v) VALUES(2, 'e', 2.17);
      INSERT OR IGNORE INTO test (id, k, v) VALUES(3, 'o', 1.618);
      COMMIT;
      "
    );
    let sth = checked_prepare(dbh, ~"SELECT * FROM test WHERE id=2");
    let r: sqlite_result<sqlite_row_result> = sth.step_row();
    let possible_row: sqlite_row_result = result::get(r);
    match possible_row {
      row(x) => {
        // x is a map::hashmap<~str, sqlite_bind_arg>
        assert x.get(~"id") == integer(2);
        assert x.get(~"k")  == text(~"e");
        assert x.get(~"v")  == number(2.17);
      }
      done => {
        fail(~"didnt get even one row back.");
      }
    }
  }