Counter Not Counting

[Asher-]

Counter does not seem to be counting up.

∴ clang -std=c++1z -I../include cx_counter.cpp 
cx_counter.cpp:6:3: error: static_assert failed "counter(1)"
  static_assert(cx::counter() == 1, "counter(1)");
  ^             ~~~~~~~~~~~~~~~~~~
cx_counter.cpp:7:3: error: static_assert failed "counter(2)"
  static_assert(cx::counter() == 2, "counter(2)");
  ^             ~~~~~~~~~~~~~~~~~~
cx_counter.cpp:8:3: error: static_assert failed "counter(3)"
  static_assert(cx::counter() == 3, "counter(3)");
  ^             ~~~~~~~~~~~~~~~~~~
3 errors generated.

[m-peko]

I suppose this counter implementation won't work when compiled with GCC 8 and above. Similar implementation works for me in case of all lower GCC versions.