On Saturday 06 October 2007 23:10:52 Mathias Gaunard wrote:
Vladimir Batov wrote:
shared_ptr is an extremely versatile and poweful gadget. One (among others) thing it handles well is incomplete classes for implementation hiding. Maybe there are other smart pointers doing that sort of thing cheaper. I am not sure.
Here is a simple deep-copying smart pointer.
Where from? I hope that one is not in productive use, because...
template<typename T> struct copy_ptr { [...] explicit copy_ptr(T* ptr_) : ptr(ptr_) { }
...this should use std::auto_ptr to make clear that ownership is transferred and...
copy_ptr(const copy_ptr& p) ptr(p.ptr ? new(ptr) T(*p.ptr) : 0) { }
copy_ptr& operator=(const copy_ptr& p) { if(ptr) { if(p.ptr) { *ptr = *p.ptr; } else { delete ptr; ptr = 0; } } else if(p.ptr) { new(ptr) T(*p.ptr); } }
...it looks like you are using placement new on a null pointer in the assignment and on an uninitialised pointer in the copy constructor, or am I missing something?
void swap(copy_ptr& p) { T* tmp = ptr; ptr = p.ptr; p.ptr = ptr; }
How about std::swap( p.ptr, ptr); ?
T* operator->() { return ptr; }
const T* operator->() const { return ptr; }
Why? I mean since when is the CV qualification of a pointer relevant for the CV qualification of the pointee? Uli