Zone of Control
The zone of control is the six hexagons next to a unit.
When an enemy unit moves into one of these hexagons, wargame rules usually state that the unit must stop moving.
The unit object has a Hexagon object that stores the units hexagon x, y coordinate.
The Line of Sight object can check the range between any 2 hexagons.
First, find the hexagon of the moving unit.
Second, loop thru the list of units. If the unit is enemy, use it's hexagon to check the range between the two.
If the range is one, then the unit is next to an enemy unit.
Note: the map is not used at all!