gistfile1.cpp

/*
 * stdout compiled without -fallocated-type-in-operator-new:
 * > 0
 * > 2
 * > 9
 * > 5
 *
 * stdout compiled without -fallocated-type-in-operator-new:
 * > Allocated at 0xb80010 as an instance of 5Klass
 * > 0
 * > Allocated at 0xb80010 as an instance of 5Klass
 * > 2
 * > Allocated at 0xb80030 as an instance of 6Klass2
 * > 9
 * > Allocated at 0xb80050 as an instance of i
 * > 5
 * > Allocated at 0xb80070 as an instance of Pi
 */
#include <iostream>
#include <typeinfo>

void* operator new(size_t size, const std::type_info &t) {
  void* address = operator new(size);
  std::cout << "Allocated at " << address << " as an instance of " << t.name() << std::endl;
  return address;
}

class Klass {
 public:
  Klass() : x_(0) {}
  Klass(int x) : x_(x) {}
  void dump() { std::cout << x_ << std::endl; }
 private:
  int x_;
};

class Klass2 {
 public:
  int x;
};

int main() {
  Klass* k;
  k = new Klass();
  k->dump();
  delete k;
  k = new Klass(2);
  k->dump();

  Klass2* k2;
  k2 = new Klass2();
  k2->x = 9;
  std::cout << k2->x << std::endl;

  int *i;
  i = new int(5);
  std::cout << *i << std::endl;

  int **pi;
  pi = new int*();

  delete k;
  delete k2;
  delete i;
  delete pi;

  return 0;
}