// PR c++/24275 template <bool val> struct bool_var { static const bool value = val; }; namespace is_inc_ { struct any { template <class T> any(T const&); }; int operator++(any const&); template <class T> struct impl { static T &x; static const bool value = sizeof(++x) == 1; }; } template<typename T> struct is_incr : bool_var< is_inc_::impl<T>::value> {}; struct not_incr{}; typedef int sa1[ is_incr<not_incr>::value ? -1 : 1];