[boost] Proposal: boost::pool fast pointer

From: Philippe A. Bouchard (philippeb_at_[hidden])
Date: 2002-07-29 23:53:57

Ok.  I've rewritten my previous proposal to draw aside unusual operator new
(size_t, ...) syntaxes by overloading the global operator new (size_t).
Pros & cons:

+ Fast smart pointer.  Cannot be faster:
    + sizeof(ptr<int>) == sizeof(int *) (for copying);
    + one operator new (size_t) call to allocate the object (no counters).
+ Memory benefits:
    + sizeof(ptr<int>) == sizeof(int *);
    + sizeof(* ptr<int>) == sizeof(int) + 1;
    + thus maximises the number of pointers growth referring to one object.
+ Simple syntax:
    + no need for policy-based functions;
    + no need to inherit from counted_base;
    + no need for operator new (size_t, ...) like in my previous examples.
+ Doesn't matter if you don't use ptr<> to assign the allocated buffer.  It
just takes a little bit more memory.

- Takes for granted that operator new (size_t) is not overloaded in specific
classes and if so, is not using direct malloc() calls.  But it would be
possible to assert at compile-time it is not overloaded.
- It would begin to be more complex for low-level dynamic memory routines.
- This is why I am recommending boost::pool as the holding namespace.

http://groups.yahoo.com/group/boost/files/ptr%3C%3E/

Again the names are temporary.  I would like your opinions first.  Here is
statement examples as shown in testptr1.cpp:
{
    ptr<child> p = new child("Bob");
    ptr<child> q = new child("Rob");
    ptr<child> r = new child("Tod");
    q = p;
    p = r;
    cout << q->f << endl;
}

IMO it would be acceptable for new projects; it doesn't matter if you assign
the buffer to a raw pointer and use an explicit delete after.  Easy to apply
on array allocations also.

Thank you,

Philippe A. Bouchard