How about adding a polymorphic array of references?


#1

My “other” language - REALbasic ( maybe C# and VB.net too ) allows one to treat arrays of object references polymorphicaly.

For example If class B inherits from class A - i can write the following code:

dim arrayB() As B
dim arrayA() as A

for i as integer = 0 to 10
arrayB.append new B()
next

arrayA = arrayB.

I could also write a method that takes an array of references to B and returns it directly as an array of type A.

Now i have no idea how this is done “under the hood” but it is a very useful thing to have in ones “arsenal”

Any chance this could be done in a future version of the JUCE arrays ?

Incidentally I have made my own extensions of some JUCE container/array classes to allow for arrays to be passed around by reference :

This is all so i can emulate the way reference counting works in REALbasic ( or VB.net for that matter )

#define REF(T) ReferenceCountedObjectPtr

#define ARRAYINTRINSIC(T) IntrinsicArrayReferenceCountedObject< T >
#define ARRAYOBJECT(T) ReferenceCountedArrayObject< T >
#define ARRAYSTRING StringArrayReferenceCountedObject

#define ARRAYREF_INTR(T) REF(ARRAYINTRINSIC(T))
#define ARRAYREF_OBJ(T) REF(ARRAYOBJECT(T))
#define ARRAYREF_STRING REF(ARRAYSTRING)

class MemoryBlockJ : public MemoryBlock, public ReferenceCountedObject
{

};

template
class IntrinsicArrayReferenceCountedObject : public Array, public ReferenceCountedObject
{
};

class StringArrayReferenceCountedObject : public StringArray, public ReferenceCountedObject
{
};

template
class ReferenceCountedArrayObject : public ReferenceCountedArray, public ReferenceCountedObject
{
public:

~ReferenceCountedArrayObject()
{
 //   Debugger();
}

};


#2

Sorry, I thought the ReferenceCountedArray would already do that. Very easy to fix, I’ll tweak it.


#3

You’re a star !.


#4

oh did you mean the polymorphic bit or just modding your current array templates to inherit from ReferenceCountedObject ?


#5

I meant the polymorphic bit. You can now do:

ReferenceCountedArray<A> a; ReferenceCountedArray<B> b (a); a = b;