http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60932
--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #5) > #ifdef __cplusplus > #include <atomic> > using namespace std; > #else > #include <stdatomic.h> > #endif > > atomic<int> i; Doh, sorry, that should say atomic_int not atomic<int> (I changed my testcase after finding the atomic_int version failed with libstdc++)