I must correct myself, it doesnt work.
This code:

#include <Core/Core.h>

using namespace Upp;

class A{
public:
	Array<int> *array;
	A(Array<int> &array_) : array(&array_){
		Cout() <<"construct A\n";
		Cout() << "Array Initial item count in A = " << array->GetCount() << "\n";
	}
};

class B : public A{
public:
	Array<int> b_array;
	void *p=&b_array;
	B() : A(b_array){
		Cout() <<"construct B\n";
		Cout() << "Array Initial item count in B = " << b_array.GetCount() << "\n";
	}
};

CONSOLE_APP_MAIN{
	B b;
	Cout() <<"Fertig\n";
	Sleep(1000000);
}

produces this output:

construct A
Array Initial item count in A = 107746496
construct B
Array Initial item count in B = 0
Fertig

So constructor A is executed, before B was constructed.

It should however work, if A doesnt use or touch the referenced array before it was constructed.