id summary reporter owner description type status milestone component version severity resolution keywords cc 12212 type_traits/integral_constant.hpp, BOOST_MPL_CFG_NO_ADL_BARRIER_NAMESPACE and mpl/integral_c.hpp unhappy together lukester_null@… John Maddock "Hello {{{ #define BOOST_MPL_CFG_NO_ADL_BARRIER_NAMESPACE #include ""boost/mpl/integral_c.hpp"" #include ""boost/type_traits/integral_constant.hpp"" int main() { return 0; } }}} {{{ In file included from main.cpp:3:0: boost/type_traits/integral_constant.hpp:42:21: error: 'integral_c' is already declared in this scope using ::mpl_::integral_c; ^ boost/type_traits/integral_constant.hpp:43:21: error: 'integral_c_tag' is already declared in this scope using ::mpl_::integral_c_tag; }}} Due to the decoupling from mpl no doubt! Regards Luke Elliott " Bugs closed To Be Determined type_traits Boost 1.61.0 Problem fixed