Re: Should the shared_ptr have release method?
In article <459e453b$0$49209$14726298@news.sunsite.dk>, Dizzy
<dizzy@roedu.net> wrote:
James Kanze wrote:
Thiago Adams wrote:
If multiple shared_ptrs are sharing ownership of the same object, and
one of them calls release, what happens to all of the others?
The release function should release the pointer only if "unique() ==
true"
Which means that after calling release, I have no way of knowing
whether I should delete the memory or not.
Hmm, release() should set the pointed to value to 0 (like auto_ptr<>) or
whatever default value sets to meaning the shared_ptr<> is not owning
anything anymore thus no problem after that deciding whether the memory
should be released or not.
I see no need for release()...
a simple
std::auto_ptr<Item> convert(shared_ptr<Item> &p) // call by reference
{
std::auto_ptr a(new Item(*p));
p.reset; // reduces count by one, etc. other copies
// this copy is now a default shared_ptr.
return a;
}
converts the shared_ptr to a default shared_ptr and returns
an auto_ptr containing the data ptr.
It is possible to possibly optimize this if the deleter of the
shared_ptr can be set at runtime to do nothing and the shared_ptr is
unique ,just moving ptrs around with public functions of shared_ptr and
the auto_ptr ctor.
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