How do compilers allocate memory for classes?

Question

When I create a class with a class pointer, for example:

class A{
    B* p_b1;
    B* p_b2;
    A(){}
}

I assume that the compiler creates space for at least 2 pointers to instance A. My question is if they are not pointers, but rather objects such as:

class A{
    B b1;
    B b2;
    A(){}
}

Will the compiler allocate space for b1 and b2 in the memory space of class A? Or will he declare the actual classes B elsewhere on the stack?

The reason I'm asking about this is because I am trying to reduce the memory allocation in my code and wandered if that made any difference.

Answer 1

b1 b2 A?

.

B ?

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Answer 2

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