struct WrappedInt { int x; }; void ?{}(WrappedInt * this) { printf("constructing int\n"); this->x = 0; } void ?{}(WrappedInt * this, WrappedInt other) { printf("copy constructing int: %d\n", other.x); this->x = other.x; } void ?{}(WrappedInt * this, int x) { printf("constructing int: %d\n", x); this->x = x; } void ^?{}(WrappedInt * this) { printf("destructing int: %d\n", this->x); } void ?=?(WrappedInt * this, int x) { printf("assigning int: %d %d\n", this->x, x); this->x = x; } struct A { WrappedInt x, y, z; }; void ?{}(A * a) { // currently must define default ctor, since there's no "= default" syntax } void ?{}(A * a, int x) { printf("begin construct A\n"); printf("construct a->x\n"); (&a->x){ x+999 }; printf("assign a->y\n"); a->y = 0; // not a constructor - default constructor will be inserted printf("end construct A\n"); } // z never constructed - will be automatically default constructed void ?{}(A * this, A other) { printf("begin copy construct A\n"); printf("copy construct this->x\n"); (&this->x){ other.x }; printf("assign this->y\n"); this->y = other.y; // not a constructor - copy constructor will be inserted printf("end copy construct A\n"); } // z never constructed - will be automatically copy constructed A ?=?(A * this, A other) { printf("begin ?=? A\n"); this->x = other.x; this->y = other.y; this->z = other.z; printf("end ?=? A\n"); return *this; } struct B { A a1, a2, a3; }; void ?{}(B * b) { printf("begin construct B\n"); printf("assign b->a2\n"); b->a2 = (A) { 2 }; printf("construct b->a1\n"); (&b->a1){ 1 }; #ifdef ERR1 (&b->a2){ b->a3 }; // error, b->a2 was used previously but is explicitly constructed #endif printf("end construct B\n"); } // a2, a3 never constructed - will be automatically default constructed void ^?{}(B * b) { b->a2 = (A) { 0 }; ^(&b->a1){}; } // a2, a3 never destructed - will be automatically destructed int main() { printf("Before declaration of b1\n"); B b1; printf("Before declaration of b2\n"); B b2 = b1; printf("End of main\n"); }