/// Return an id generator that generatest `start` as the first fresh id.
///
/// The start id must be even.
Return an id generator that generatest `start` as the first fresh id.
The start id must be even.
Return an id generator that generatest ` start ` as the first fresh id . The start id must be even .
pub fn new(start: u64) -> IdGen {
        assert_eq!(start % 2, 0, "IdGen start must be even.");
        IdGen {
            next_even: start,
            next_odd: start + 1,
        }
    }
pub fn new ( start : u64 ) -> IdGen { assert_eq ! ( start 2 0 " " ) ; IdGen { next_even : start , next_odd : start + 1 , } }
Return an id generator that generatest `start` as the first fresh id.
Return an id generator that generatest ` start ` as the first fresh id .
start
u64