No suitable conversion function from [class name] to [class name]* - c++-cli

Question

I am new to c++/cli, the situation I faced is that:
the project I am doing needs to use an external dll, in my functions I need to use classes A, B and C which are from this dll, I put them in my .h file, the .h file looking like:
#include library I use
public ref class MyClass
{
public:
MyClass();
~MyClass();
otherfuc();
private:
A *a;
B *b;
C *c;
}
My .cpp file looking like:
MyClass::MyClass()
{
a = new A();
b = new B(*a);
c = b->func(); //error happened
}
MyClass::otherfunc()
{
c->func_c()
}
Class A, B, C are unmanaged class, so I only have one way to declare them in managed class, just like I do in the header file. In class B, it has a function which is called func, this function return class type C, I tried c = &b->func(), in this way, it will throw AccessViolationException, if I tried c = b->func, then the error is function call missing argument. What should I do, please help!!!

Answer 1

From what you've written my guess is that B::func() is declared to return a C instance as a temporary:
class B {
public:
C func();
};
Allocate an instance of C as a copy of temporary:
class A {
};
class C {
public:
C(int _i) : i(_i) {}
int func_c() { return i; }
int i;
};
class B {
public:
B(A & a) {}
C func() { return C(5); }
};
public ref class MyClass {
public:
MyClass();
~MyClass();
int otherfunc();
private:
A *a;
B *b;
C *c;
};
MyClass::MyClass()
{
a = new A();
b = new B(*a);
c = new C(b->func());
}
MyClass::~MyClass() {
delete a;
delete b;
delete c;
}
int MyClass::otherfunc()
{
return c->func_c();
}
void f() {
MyClass^ mc = gcnew MyClass();
int i = mc->otherfunc();
}
This assumes C is copyable (or moveable) and that copying it make sense for what you are doing.