用C ++分配内存然后在Cython中解除分配？

Question

I have a C++ function that allocates an array and returns it. I want to use this array within Cython and then delete it when finished, but Cython doesn't seem to be happy with the way I'm trying to do this. The most trivial example:

foo.hpp:

float * my_fun() { return new float[5]; }

foo.pyx:

cdef extern from "foo.hpp":
  float * my_fun()

def my_other_fun():
  cdef float * foo = my_fun()
  del foo

When I try cython -a foo.pyx I get the error Deletion of non-Python, non-C++ object . What gives? Also if there's a way to accomplish this without having to allocate heap memory, I'm all ears.

Answer 1

Memory should always be freed in the same way that it is allocated. You are asking for trouble doing what you are doing.

Off hand I can think of two ways to address this problem:

1) Have a delete function in C++ that you call to free the memory.

2) Allocate the memory directly from a system service or library call (eg malloc) and use the corresponding function to free the memory.