* mallocator is empty
* @param free_f function to free an object of your datatype, called in @a xbt_mallocator_release() when the stack is
* full, and when the mallocator is freed.
* mallocator is empty
* @param free_f function to free an object of your datatype, called in @a xbt_mallocator_release() when the stack is
* full, and when the mallocator is freed.