Mathf.Infinity

Description

A representation of positive infinity (Read Only).

// Casts a ray from (0,0,0) towards (0,0,1) to the infinity and prints a message
// if any object has touched the ray.
// To test it, just place any object and intersect it with the white drawn line

function Update () {
    // shows the line that follows the ray.
    Debug.DrawLine(Vector3.zero, Vector3.forward * 100);
    if (Physics.Raycast (Vector3.zero, Vector3.forward, Mathf.Infinity)) {
        print ("There is something in front of the object!");
    }
}

no example available in C#