MPL Overloads: template<> missing

[ax3l]

Compiling boost MPL with (NVCC 10.1.168 and) GCC 6.4.0 and -Wall -Wextra throws the following warnings. Mainly -Wnon-template-friend and operatorXY ... declares a non-template function -- add <> to refer to a template instance

Generally, the macros for overloads seem to lack template <> and similar annotations:

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp(54): warning: "boost::mpl::aux::type_wrapper<T> operator/(const boost::mpl::m_item<Key, T, Base> &, boost::mpl::aux::type_wrapper<Key> *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp(55): warning: "boost::mpl::aux::type_wrapper<boost::mpl::pair<Key, T>> operator|(const boost::mpl::m_item<Key, T, Base> &, boost::mpl::next<Base::order>::type *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp(56): warning: "char (&operator||(const boost::mpl::m_item<Key, T, Base> &, boost::mpl::aux::type_wrapper<Key> *))[boost::mpl::next<Base::order>::type::value]" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp(71): warning: "boost::mpl::aux::type_wrapper<mpl_::void_> operator/(const boost::mpl::m_mask<Key, Base> &, boost::mpl::aux::type_wrapper<Key> *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp(72): warning: "boost::mpl::aux::type_wrapper<mpl_::void_> operator|(const boost::mpl::m_mask<Key, Base> &, boost::mpl::x_order_impl<Base, Key>::type *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/set/aux_/item.hpp(47): warning: "char (&operator||(const boost::mpl::s_item<T, Base> &, boost::mpl::aux::type_wrapper<T> *))[boost::mpl::next<Base::order>::type::value]" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/set/aux_/item.hpp(48): warning: "boost::mpl::aux::no_tag operator%(const boost::mpl::s_item<T, Base> &, boost::mpl::aux::type_wrapper<T> *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/set/aux_/item.hpp(63): warning: "boost::mpl::aux::yes_tag operator%(const boost::mpl::s_mask<T, Base> &, boost::mpl::aux::type_wrapper<T> *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/set/aux_/item.hpp(77): warning: "boost::mpl::aux::no_tag operator%(const boost::mpl::s_unmask<T, Base> &, boost::mpl::aux::type_wrapper<T> *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp(54): warning: "boost::mpl::aux::type_wrapper<T> operator/(const boost::mpl::m_item<Key, T, Base> &, boost::mpl::aux::type_wrapper<Key> *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp(55): warning: "boost::mpl::aux::type_wrapper<boost::mpl::pair<Key, T>> operator|(const boost::mpl::m_item<Key, T, Base> &, boost::mpl::next<Base::order>::type *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp(56): warning: "char (&operator||(const boost::mpl::m_item<Key, T, Base> &, boost::mpl::aux::type_wrapper<Key> *))[boost::mpl::next<Base::order>::type::value]" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp(71): warning: "boost::mpl::aux::type_wrapper<mpl_::void_> operator/(const boost::mpl::m_mask<Key, Base> &, boost::mpl::aux::type_wrapper<Key> *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp(72): warning: "boost::mpl::aux::type_wrapper<mpl_::void_> operator|(const boost::mpl::m_mask<Key, Base> &, boost::mpl::x_order_impl<Base, Key>::type *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/set/aux_/item.hpp(47): warning: "char (&operator||(const boost::mpl::s_item<T, Base> &, boost::mpl::aux::type_wrapper<T> *))[boost::mpl::next<Base::order>::type::value]" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/set/aux_/item.hpp(48): warning: "boost::mpl::aux::no_tag operator%(const boost::mpl::s_item<T, Base> &, boost::mpl::aux::type_wrapper<T> *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/set/aux_/item.hpp(63): warning: "boost::mpl::aux::yes_tag operator%(const boost::mpl::s_mask<T, Base> &, boost::mpl::aux::type_wrapper<T> *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/set/aux_/item.hpp(77): warning: "boost::mpl::aux::no_tag operator%(const boost::mpl::s_unmask<T, Base> &, boost::mpl::aux::type_wrapper<T> *)" declares a non-template function -- add <> to refer to a template instance

linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp: At global scope:
linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp:54:83: warning: friend declaration 'boost::mpl::aux::type_wrapper<Key> boost::mpl::operator/(const boost::mpl::m_item<Key, T, Base>&, boost::mpl::aux::type_wrapper<T>*)' declares a non-template function [-Wnon-template-friend]
     BOOST_MPL_AUX_MAP_OVERLOAD( aux::type_wrapper<T>, VALUE_BY_KEY, m_item, aux::type_wrapper<Key>* );
                                                                                   ^
linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp:54:83: note: (if this is not what you intended, make sure the function template has already been declared and add <> after the function name here) 
linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp:55:77: warning: friend declaration 'boost::mpl::aux::type_wrapper<boost::mpl::pair<T1, T2> > boost::mpl::operator|(const boost::mpl::m_item<Key, T, Base>&, boost::mpl::m_item<Key, T, Base>::order*)' declares a non-template function [-Wnon-template-friend]
     BOOST_MPL_AUX_MAP_OVERLOAD( aux::type_wrapper<item>, ITEM_BY_ORDER, m_item, order* );
                                                                             ^
linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp:56:72: warning: friend declaration 'char (& boost::mpl::operator||(const boost::mpl::m_item<Key, T, Base>&, boost::mpl::aux::type_wrapper<T>*))[boost::mpl::m_item<Key, T, Base>::order:: value]' declares a non-template function [-Wnon-template-friend]
     BOOST_MPL_AUX_MAP_OVERLOAD( order_tag_, ORDER_BY_KEY, m_item, aux::type_wrapper<Key>* );
                                                                        ^
linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp:71:93: warning: friend declaration 'boost::mpl::aux::type_wrapper<mpl_::void_> boost::mpl::operator/(const boost::mpl::m_mask<Key, Base>&, boost::mpl::aux::type_wrapper<T>*)' declares a non-template function [-Wnon-template-friend]
     BOOST_MPL_AUX_MAP_OVERLOAD( aux::type_wrapper<void_>, VALUE_BY_KEY, m_mask, aux::type_wrapper<Key>* );
                                                                                             ^
linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/map/aux_/item.hpp:72:79: warning: friend declaration 'boost::mpl::aux::type_wrapper<mpl_::void_> boost::mpl::operator|(const boost::mpl::m_mask<Key, Base>&, boost::mpl::m_mask<Key, Base>::key_order_*)' declares a non-template function [-Wnon-template-friend]
     BOOST_MPL_AUX_MAP_OVERLOAD( aux::type_wrapper<void_>, ITEM_BY_ORDER, m_mask, key_order_* );
                                                                               ^
linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/set/aux_/item.hpp:47:70: warning: friend declaration 'char (& boost::mpl::operator||(const boost::mpl::s_item<T, Base>&, boost::mpl::aux::type_wrapper<T>*))[boost::mpl::s_item<T, Base>::order:: value]' declares a non-template function [-Wnon-template-friend]
     BOOST_MPL_AUX_SET_OVERLOAD( order_tag_, ORDER_BY_KEY, s_item, aux::type_wrapper<T>* );
                                                                      ^
linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/set/aux_/item.hpp:48:70: warning: friend declaration 'char (& boost::mpl::operator%(const boost::mpl::s_item<T, Base>&, boost::mpl::aux::type_wrapper<T>*))[1]' declares a non-template function [-Wnon-template-friend]
     BOOST_MPL_AUX_SET_OVERLOAD( aux::no_tag, IS_MASKED, s_item, aux::type_wrapper<T>* );
                                                                      ^
linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/set/aux_/item.hpp:63:71: warning: friend declaration 'char (& boost::mpl::operator%(const boost::mpl::s_mask<T, Base>&, boost::mpl::aux::type_wrapper<T>*))[2]' declares a non-template function [-Wnon-template-friend]
     BOOST_MPL_AUX_SET_OVERLOAD( aux::yes_tag, IS_MASKED, s_mask, aux::type_wrapper<T>* );
                                                                       ^
linux-rhel7-ppc64le/gcc-6.4.0/boost-1.66.0-nxj2e2htxvm25phwnxtwbw3bajgcryko/include/boost/mpl/set/aux_/item.hpp:77:72: warning: friend declaration 'char (& boost::mpl::operator%(const boost::mpl::s_unmask<T, Base>&, boost::mpl::aux::type_wrapper<T>*))[1]' declares a non-template function [-Wnon-template-friend]
     BOOST_MPL_AUX_SET_OVERLOAD( aux::no_tag, IS_MASKED, s_unmask, aux::type_wrapper<T>* );

Seen with PIConGPU 0.5.0-dev as of ComputationalRadiationPhysics/picongpu@1347ebb (and way before as well).

Small example with NVCC 10.1 that triggers this via the boost property tree:
https://cuda.godbolt.org/z/ir3p6i

#include <boost/property_tree/ptree.hpp>

int main()
{
  using boost::property_tree::ptree;
  ptree pt;
}

[ax3l]

The same warnings exist in boost 1.70.0

[jeking3]

Hi, does #62 fix this?

[masterleinad]

Hi, does #62 fix this?

Doesn't look like it.

[masterleinad]

https://cuda.godbolt.org/z/s73P9a553 demonstrates that this warning still occurs with boost-1.81.0.