Question

I am writing a Generic Binary Search Tree. I need to compare two generic types. How to do it, assuming the the user has implemented IComparable in T class.

private void Insert(T newData, ref Node<T> currentRoot)
{
    if (currentRoot == null)
    {
        currentRoot = new Node<T>(newData);
        return;
    }
    if (newData <= currentRoot.data) //doesn't work, need equivalent functionality
         Insert(newData, ref currentRoot.lChild);
    else
         Insert(newData,  ref currentRoot.rChild); 
}

Answer 1

You have to add a generic constraint where T: IComparable<T> to your method to make the CompareTo() method available to instances of your type T.

private void Insert(T newData, ref Node<T> currentRoot) where T: IComparable<T>
{
  //...
}

Then you can use:

if (newData.CompareTo(currentRoot.data) <= 0) 
{
   //...
}