share_ptr 引用计数的实现

template <typename _Ty>
class kshare_ptr
{
public:
kshare_ptr(_Ty* _t = NULL)
: m_Ty(_t)
{
m_pRef = new size_t(1);
}

~kshare_ptr()
{
--*m_pRef;
if (*m_pRef == 0)
{
delete m_pRef;
m_pRef = NULL;

delete m_Ty;
m_Ty = NULL;
}
}

kshare_ptr(const kshare_ptr<_Ty>& _rhs)
{
m_pRef = _rhs.m_pRef;
++*m_pRef;
m_Ty = _rhs.m_Ty;
}

kshare_ptr& operator=(const kshare_ptr<_Ty>& _rhs)
{
if (this == &_rhs)
{
return *this;
}

--*m_pRef;
if (m_pRef == 0)
{
delete this;
}

++*_rhs.m_pRef;
m_Ty = _rhs.m_Ty;

return *this;
}

public:
_Ty*                m_Ty;
size_t*             m_pRef;
};