hm... WTF...
//a
const unsigned test_a (12); //OK
//b
const unsigned test_b { 12}; //bricht
//c
const unsigned test_c = 12; // OK
//"Leere" Zeile
;
const unsigned test_leerzeile {12}; //ok
//constexpr
constexpr unsigned test_constexpr {12}; //OKdu findest Sachen...