What is the difference between the heap and the free store? [duplicate]

Answer 1

In Herb's book "Exceptional C++", he defines:

Heap: A dynamic memory area that is allocated/freed by the malloc/free functions.

Free Store: A dynamic memory area that is allocated/freed by new/delete.

Its possible for new and delete to be implemented in terms of malloc and free, so technically, they could be the same memory area. However, as the standard doesn't specify this, its best to treat them separatly, and not to mix malloc/delete or new/free.

Answer 2

Well, the current C++ standard only uses the term "free store" - the only use of "heap" in the Standard is to describe the heap data structure in the Standard Library. So "heap" is not a very useful term to use when trying to discuss C++ problems accurately, though of course everyone does it.

Answer 3

The free-store technically isn't the heap, just as local variables technically aren't on the stack. However, it's extremely rare in my experience to find anybody who won't accept those terms.