array of parent structs does no accept child structs

[limscafo]

struct Robot
{
	var() String robotName;
};

struct RobotWithAntenna extends Robot
{
	var() String antennaName;
};

function Test()
{
	local RobotWithAntenna myAntennaRobot;
	local array<Robot> robots;
	
	myAntennaRobot.robotName = "Hans";
	myAntennaRobot.antennaName = "Model X v.2";
	
	robots.AddItem(myAntennaRobot);
}

Causes Error:

Type mismatch in additem(...)

How do I do that?

[Wormbo]

Structs, unlike classes, are not polymorphic. In the .NET world you'd call them "value types", because the struct value itself would be stored in the array, not a reference to the struct value. Consequently, if you derive a struct from another struct, it will be larger and by design not fit into an array of the smaller struct type.