template<class T>
struct A {
  static const int val = sizeof(T);
  static_assert(val != 0, "message");
};

static_assert(true, "message");

namespace ns {
  static_assert(1 + 1 == 2, "message");
}

struct B {
  static_assert(true, "message");
};

int main() {
  static_assert(A<char>::val == sizeof(char), "message");
  return 0;
}