id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
9913,boost::has_complement of enum class does not compile,Nevin Liber <nevin@…>,bronf,"(Also filed this as a gcc bug at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60852)

This works under gcc 4.7.2 and clang 3.4, but fails to compile under gcc 4.9 RC1.  enum class seems to be the only issue; plain enums work fine.

#include <boost/type_traits.hpp>
#include <iostream>

enum class E {};

int main()
{ std::cout << boost::has_complement<E>() << std::endl; }

Using Boost 1.55 and g++ -std=c++11, we get:

In file included from /opt/local/include/boost/config.hpp:57:0,
                 from /opt/local/include/boost/type_traits/add_const.hpp:13,
                 from /opt/local/include/boost/type_traits.hpp:13,
                 from a.cpp:1:
/opt/local/include/boost/type_traits/detail/has_prefix_operator.hpp: In instantiation of 'const bool boost::detail::has_complement_impl::operator_exists<E>::value':
/opt/local/include/boost/type_traits/detail/has_prefix_operator.hpp:173:4:   required from 'const bool boost::detail::has_complement_impl::trait_impl1<E, boost::detail::has_complement_impl::dont_care, false>::value'
/opt/local/include/boost/type_traits/detail/has_prefix_operator.hpp:195:4:   required from 'const bool boost::detail::has_complement_impl::trait_impl<E, boost::detail::has_complement_impl::dont_care>::value'
/opt/local/include/boost/type_traits/detail/has_prefix_operator.hpp:202:1:   required from 'struct boost::has_complement<E>'
a.cpp:7:41:   required from here
/opt/local/include/boost/type_traits/detail/has_prefix_operator.hpp:152:56: error: no match for 'operator~' (operand type is 'E')
    BOOST_STATIC_CONSTANT(bool, value = (sizeof(check(((BOOST_TT_TRAIT_OP make<Rhs>()),make<has_operator>())))==sizeof(::boost::type_traits::yes_type)));
                                                        ^
/opt/local/include/boost/type_traits/detail/has_prefix_operator.hpp: In instantiation of 'const bool boost::detail::has_complement_impl::operator_returns_void<E>::value':
/opt/local/include/boost/type_traits/detail/has_prefix_operator.hpp:173:4:   required from 'const bool boost::detail::has_complement_impl::trait_impl1<E, boost::detail::has_complement_impl::dont_care, false>::value'
/opt/local/include/boost/type_traits/detail/has_prefix_operator.hpp:195:4:   required from 'const bool boost::detail::has_complement_impl::trait_impl<E, boost::detail::has_complement_impl::dont_care>::value'
/opt/local/include/boost/type_traits/detail/has_prefix_operator.hpp:202:1:   required from 'struct boost::has_complement<E>'
a.cpp:7:41:   required from here
/opt/local/include/boost/type_traits/detail/has_prefix_operator.hpp:89:102: error: no match for 'operator~' (operand type is 'E')
    BOOST_STATIC_CONSTANT(bool, value = (sizeof(::boost::type_traits::yes_type)==sizeof(returns_void((BOOST_TT_TRAIT_OP make<Rhs>(),returns_void_t())))));
                                                                                                      ^
a.cpp: In function 'int main()':
a.cpp:7:41: error: cannot bind 'std::ostream {aka std::basic_ostream<char>}' lvalue to 'std::basic_ostream<char>&&'
 { std::cout << boost::has_complement<E>() << std::endl; }
                                         ^
In file included from /opt/local/include/gcc49/c++/istream:39:0,
                 from /opt/local/include/gcc49/c++/sstream:38,
                 from /opt/local/include/gcc49/c++/complex:45,
                 from /opt/local/include/boost/type_traits/is_complex.hpp:12,
                 from /opt/local/include/boost/type_traits.hpp:49,
                 from a.cpp:1:
/opt/local/include/gcc49/c++/ostream:602:5: note: initializing argument 1 of 'std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&&, const _Tp&) [with _CharT = char; _Traits = std::char_traits<char>; _Tp = boost::has_complement<E>]'
     operator<<(basic_ostream<_CharT, _Traits>&& __os, const _Tp& __x)
     ^
",Bugs,closed,To Be Determined,type_traits,Boost 1.55.0,Problem,obsolete,,nevin@…