OptionalIndex

    pub const OptionalIndex = enum(u32) {
        none = max_u32,
        _,

        pub fn init(i: Index) OptionalIndex {
            const result: OptionalIndex = @fromBackingInt(@intCast(@backingInt(i)));
            assert(result != .none);
            return result;
        }

        pub fn unwrap(this: @This()) ?Index {
            return switch (this) {
                .none => null,
                _ => @fromBackingInt(@intCast(@backingInt(this))),
            };
        }

        pub fn get(this: @This(), c: *const Configuration) ?TargetQuery {
            return (this.unwrap() orelse return null).get(c);
        }
    }