在C ++中将函数作为参数传递

Question

I have the following call:

void Derived::GetEntry(Skill&);
InorderTraverse(GetEntry);

Which calls

void Base<ItemType>::InorderTraverse(void Visit(ItemType&)) const

Attempting to compile as written generates

error C3867: 'Derived::GetEntry': function call missing argument list; use '&Derived::GetEntry' to create a pointer to member

Using &Derived::GetEntry generates

cannot convert parameter 1 from 'void (__thiscall Derived::* )(Skill &)' to 'void (__cdecl *)(ItemType &)'

Changing the declaration to static void GetEntry... fixes these problems, but creates a new set of problems (namely that I can't access non-static objects (nonstatic member reference must be relative to a specific object)

I have a similar traversal operation that works fine with a static declaration, since the called function just displays information about each object on which it is called.

I've been searching for a few days now for an answer, and I feel like it's something simple. Is there a way to use a nonstatic function as a parameter in another function call?

The complete code is: https://github.com/mindaika/SkillTree

Answer 1

Edit: Inserted full working example instead.

I suggest you use the std function pointers instead.

For instance:

#include <functional>
void main()
{
class TheClass
{
public:

   TheClass()
   {
       m_function = ( std::tr1::bind(&TheClass::run, this) );
   };

   void run()
   {
          // stuff to do
   };

   std::tr1::function<void ()> m_function;
};

TheClass theclass;
theclass.m_function();

}

m_function (); // call function

Answer 2

As I mentioned in my question, I was trying to get around the "memory leak" caused by using a static variable (it's not actually a leak, since statics are destroyed, but not until after the leak detector runs). I ended up using a modification of the encapsulated pointer described here: C++ freeing static variables