Is delete and delete[] equivalent for basic data types

Question

So during a code review, a colleague of mine used a double* d = new double[foo]; and then called delete d. I told them that they should change it to delete [] d. And they stated that the compiler doesn't need that for basic data types. I disagreed.

So I thought I'd prove my point with an experiment:

#define NUM_VALUES 10000
int main(int argc,char** argv)
{
  int i = 0;
  while (true)
  {
    std::cout << i << "|";
    double* d = new double[NUM_VALUES];
    std::cout << ((void*)d) << std::endl;
    for (int j = 0; j < NUM_VALUES; j++)
      d[j] = j;

    delete d;
    i++;
  }

  return 0;
}

Not only does the memory usage not grow, but d is allocated to the same place every time! (Visual Studio 2010). Is this a quirk of the visual studio compiler? Or is this part of the standard?

Answer 1

If you use new you need to use delete

If you use new [] you have to use delete []

They mean different things. double* d = new double(); means allocate and construct a double type. delete d; means unallocated and destruct a single double type. double* d = new double[NUM_VALUES]; means allocate NUM_VALUES doubles and delete [] d means unallocated each of of the NUM_VALUES doubles allocated.