🚀 go-pugleaf

Given

class Malloc {
public:
  void *allocate(size_t sz);
  void  deallocate(void *ptr);
};

void *operator new(size_t sz,Malloc *myalloc)
{
  return(myalloc->allocate(sz));
}
void operator delete(void *ptr,Malloc *myalloc)  // new in WP ??
{
  myalloc->deallocate(ptr);
}

class Base {
public:
  Base();
  virtual ~Base();
};

class Derived : public Base {
public:
  Derived();
 ~Derived();
};

void fred(Malloc *myalloc)
{
  double *a = new(myalloc) double[1024];
  double *b = new(myalloc) double;
  Base   *c = new(myalloc) Derived[1024];
  Base   *d = new(myalloc) Derived;

...   lots of code

// HOW do i free a,b,c & d so that
// (1) all the destructors are called
// (2) the memory is deallocated

  delete(myalloc) [] a;         // not C++
  delete(myalloc)    b;         // not C++
  delete(myalloc) [] c;         // not C++
  delete(myalloc)    d;         // not C++

// call manually

  ::operator delete(a,myalloc);
  ::operator delete(b,myalloc);

// will this call the destructor for the 1024 Derived elements created
// & deallocate all the memory

  ::operator delete(c,myalloc);

// will this call the destructor for the 1 Derived element created
// & deallocate all the memory

  ::operator delete(d,myalloc);
}

Other questions this code raises is

(1)

Will size_t sz passed to new(size_t sz,Malloc *mymalloc)
include the overhead for the number of objects allocated ??
and will the compiler adjust the retured pointer so that
a,b,c & d point to the start of array, not at the number of objects ?

(P.S) Microsoft Visual C++ 2.0 works OK here

(2)

How can the compiler known that c was an array of objects allocated,
especially if c is deleted in a different compilation unit.
Is there a specific syntax for this.

I'm guessing but, do I need to declare

void *operator new[](size_t sz,Malloc *myalloc) &
void *operator delete[](size_t sz,Malloc *myalloc)

Alan Gray
4D Solutions PTY LTD

PO BOX 103 Narrabeen NSW
2101 Australia

agray@ozemail.com.au
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