Function pointers and forward declaration

[tobias_ebsen]

hi !!

i have i function pointer that i declared in unmanaged code:

void (*func_ptr)();

and i have a managed class where i need to assign a pointer to this
function pointer and then call it. check out this code:

ref class MyClass; // forward declaration

void Func() {
MyClass::MyStaticFunc(); // this generates C3083, C2039 and C3861
}

public ref class MyClass {
public:
MyClass() {
func_ptr = &Func;
func_ptr();
}

static void MyStaticFunc() {
}
};

----------------------------------------------------------

as you can see my compiler won't accept the forward declaration...
i have also tried assigning func_ptr = &MyStaticFunc which won't work
unless MyStaticFunc is a delegate...

any clues??? please....

THANKS ALOT!

[Doug Harrison [MVP]]

On 14 Jan 2007 14:20:29 -0800, to**********@hotmail.com wrote:

>hi !!

i have i function pointer that i declared in unmanaged code:

void (*func_ptr)();

and i have a managed class where i need to assign a pointer to this
function pointer and then call it. check out this code:

ref class MyClass; // forward declaration

void Func() {
MyClass::MyStaticFunc(); // this generates C3083, C2039 and C3861
}

public ref class MyClass {
public:
MyClass() {
func_ptr = &Func;
func_ptr();
}

static void MyStaticFunc() {
}
};

----------------------------------------------------------

as you can see my compiler won't accept the forward declaration...
i have also tried assigning func_ptr = &MyStaticFunc which won't work
unless MyStaticFunc is a delegate...

any clues??? please....

You can't use incomplete classes in that way. The function Func needs to
see the definition of MyClass in order to call MyStaticFunc, so rearranging
things like this should work:

void Func();

public ref class MyClass {
public:
MyClass() {
func_ptr = &Func;
func_ptr();
}

static void MyStaticFunc() {
}
};

void Func() {
MyClass::MyStaticFunc(); // this generates C3083, C2039 and C3861
}

--
Doug Harrison
Visual C++ MVP