module interface3; extern(C) int printf(char*,...); interface I { void func(); } class C : I { int i = 42; override void func() { printf("hello %d from %p\n", i, this); i++; } } void main() { auto c = new C; {c.func();} { I i = c; {i.func();} } {printf("final %d\n", c.i);} {assert(c.i == 44);} }