local_shared_ptr have no assertions checks if operators "->" or "*" are called

[Lev275568]

local_shared_ptr:

    typename boost::detail::sp_dereference< T >::type operator* () const noexcept
    {
        return *px;
    }

    typename boost::detail::sp_member_access< T >::type operator-> () const noexcept
    {
        return px;
    }

shared_ptr have BOOST_ASSERT( px != 0 ); before return.

I think it will be useful.