label : { if ( condition ) { statement goto label ; } }
struct A { int val; A(int i) : val(i) { } ~A() { } operator bool() { return val != 0; } }; int i = 1; while (A a = i) { // ... i = 0; }In the while-loop, the constructor and destructor are each called twice, once for the condition that succeeds and once for the condition that fails. — end example