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'shared_from_this' added.

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[SVN r14561]
This commit is contained in:
Peter Dimov
2002-07-22 16:36:52 +00:00
parent 33077bda71
commit 3f0ebd4c71
2 changed files with 48 additions and 1 deletions
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22
include/boost/shared_ptr.hpp
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@ -313,6 +313,28 @@ template<typename T> inline T * get_pointer(shared_ptr<T> const & p)
return p.get();
}
// shared_from_this() creates a shared_ptr from a raw pointer (usually 'this')
namespace detail
{
inline void sp_assert_counted_base(boost::counted_base const *)
{
}
template<class T> inline T * sp_remove_const(T const * p)
{
return const_cast<T *>(p);
}
} // namespace detail
template<class T> shared_ptr<T> shared_from_this(T * p)
{
detail::sp_assert_counted_base(p);
return shared_ptr<T>(detail::sp_remove_const(p));
}
} // namespace boost
#ifdef BOOST_MSVC

27
shared_ptr_test.cpp
View File

@ -112,6 +112,16 @@ public:
std::cout << "Z(" << this << ")::~Z()\n";
}
boost::shared_ptr<Z> shared_this()
{
return boost::shared_from_this(this);
}
boost::shared_ptr<Z const> shared_this() const
{
return boost::shared_from_this(this);
}
private:
Z(Z const &);
@ -331,9 +341,24 @@ int test_main(int, char * [])
{
// test intrusive counting
boost::shared_ptr<void> pv(new Z);
boost::shared_ptr<void> pv(new Z);
boost::shared_ptr<Z> pz = boost::shared_static_cast<Z>(pv);
BOOST_TEST(pz.use_count() == pz->use_count());
// test shared_from_this
boost::shared_ptr<Z> pz2 = pz->shared_this();
Z const & z = *pz2;
boost::shared_ptr<Z const> pz3 = z.shared_this();
BOOST_TEST(pz.use_count() == pz->use_count());
BOOST_TEST(pz2.use_count() == pz2->use_count());
BOOST_TEST(pz3.use_count() == pz3->use_count());
BOOST_TEST(pz.use_count() == pz2.use_count());
BOOST_TEST(pz.use_count() == pz3.use_count());
}
}