Using gcc with option -W I get the following warning when using a Boost.MultiIndex container inside a copy constructor: /usr/local/include/boost-1_33_1/boost/multi_index_container.hpp: In copy constructor 'boost::multi_index::multi_index_container<Value, IndexSpecifierList, Allocator>::multi_index_container(const boost::multi_index::multi_index_container<Value, IndexSpecifierList, Allocator>&) [with Value = ListenMonitor::ListenZeile, IndexSpecifierList = boost::multi_index::indexed_by<boost::multi_index::ordered_unique<boost::multi_index::identity<ListenMonitor::ListenZeile>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, Allocator = std::allocator<ListenMonitor::ListenZeile>]': liste.hpp:139: instantiated from here /usr/local/include/boost-1_33_1/boost/multi_index_container.hpp:204: warning: base class 'struct boost::multi_index::detail::header_holder<boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<ListenMonitor::ListenZeile>
, boost::multi_index::multi_index_container<ListenMonitor::ListenZeile, boost::multi_index::indexed_by<boost::multi_index::ordered_unique<boost::multi_index::identity<ListenMonitor::ListenZeile>, mpl_::na, mpl_::na>, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, std::allocator<ListenMonitor::ListenZeile> > >' should be explicitly initialized in the copy constructor
The 'ListenMonitori::Listenzeile' stuff is from me. But the issue does not depend on that. I would assume that copying a multi index is not forbidden and using Is there a way to get rid of that warning? I am trying hard to produce warning free code, and in this case I am not sure if the warning is just ugly or if it is a real problem in the code. [gcc --version: gcc (GCC) 4.1.2 20061115 (prerelease) (SUSE Linux) ] I have attached a trivial example that demonstrates the issue. I have modified the example/basic.cpp: I have added a trivial class XXX that contains employee_set. When copying objects of XXX the above warning is issued by gcc. Best regards Christoph