fn as_any(&self) -> &dyn Any {
        self
}

/// Specifies objective cost type.
pub trait ObjectiveCost {
    /// Returns absolute value of objective.
    fn value(&self) -> Cost;

    /// Compares objectives costs together, returns (`actual`, `relaxed`) ordering.
    fn cmp_relaxed(&self, other: &Box<dyn ObjectiveCost + Send + Sync>) -> (Ordering, Ordering);

    /// Clones objective cost.
    fn clone_box(&self) -> Box<dyn ObjectiveCost + Send + Sync>;

    /// Returns objective cost as `Any`.
    fn as_any(&self) -> &dyn Any;
}

pub unsafe fn as_mut<T>(reference: &T) -> &mut T {
    let const_ptr = reference as *const T;
    let mut_ptr = const_ptr as *mut T;
    &mut *mut_ptr
}