In the standard C++ TR1 draft, I find the following regulation:

2.2.3.2 shared_ptr destructor
~shared_ptr();
1 Effects:
- If *this is empty, there are no side effects.
- If *this shares ownership with another shared_ptr instance
(use_count() >
1), decrements that instance's
use count.
- Otherwise, if *this owns a pointer p and a deleter d, d(p) is
called.
- Otherwise, *this owns a pointer p, and delete p is called.
2 Throws: nothing.

But when I refer to shared_ptr.hpp implemented by Boost,I can't find
any destructors of shared_ptr.Who can tell me how it is implemented?I
will be appreciative.

The library Boost can be downloaded as a .zip file at the following
webpage:
http://sourceforge.net/project/showfiles.php?group_id=7586
And the webpage of Boost is http://boost.sourceforge.net/.

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hzhuo1@gmail.com wrote:
> In the standard C++ TR1 draft, I find the following regulation:
>
[...]
>
> But when I refer to shared_ptr.hpp implemented by Boost,I can't find
> any destructors of shared_ptr.

The compiler generated implentation does the right thing -- it calls
the destructor on each member and one of these (specifically, the
detail::shared_count member) does the action described in your quote
from TR1.

>Who can tell me how it is implemented?I

Have a look in boost/detail/shared_count.hpp.  But if you just want to
know what it does, rather than how it does it, it does what the boost
and/or TR1 documentation says it does.

--
Richard Smith

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