What I mean is that the difference doesn't affect the wrapper. Your example shows the situation of purely go code, but the wrapper code doesn't purely go code -- although the "path" are different, the destination is the same.
If your code acts as a wrapper -- let's say that A.m2 will call test_A_m2, the polymorphism on C++ side is still available. If we passed a pointer of an A object to test_A_m2, it will call A::m2; if we passed a pointer of B object to test_A_m2, it will call B::m2. 在 2016年10月4日星期二 UTC+8下午9:47:11，Ian Lance Taylor写道： > > On Tue, Oct 4, 2016 at 6:33 AM, Shengqiu Li <[email protected] > <javascript:>> wrote: > > Thanks for your reply. In my view, the difference seems not affect the > > behavior. As we store the pointer of the C++ object, when we call a C++ > > virtual function in Go and the object itself is an instance of child > class, > > calling the parent's function or the child's function are the same -- > > finally they will call the child's function in C++. For example, > > Here is an example showing the difference. > > C++ code: > > ==================================================== > #include <iostream> > > class A { > public: > virtual void m1() { std::cout << "A::m1\n"; m2(); } > virtual void m2() { std::cout << "A::m2\n"; } > }; > > class B : public A { > virtual void m2() { std::cout << "B::m2\n"; } > }; > > int main() { > B b; > b.m1(); > } > ===================================================== > > Go code: > > ===================================================== > package main > > import "fmt" > > type A struct{} > > func (a A) m1() { > fmt.Println("A.m1") > a.m2() > } > > func (a A) m2() { > fmt.Println("A.m2") > } > > type B struct { > A > } > > func (b B) m2() { > fmt.Println("B.m2") > } > > func main() { > var b B > b.m1() > } > ================================================= > > The C++ program will print > > A::m1 > B::m2 > > The Go program will print > > A.m1 > A.m2 > > Ian > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
