function-pointers

I want to call the base class implementation of a virtual function using a member function pointer. class Base { public: virtual void func() { cout << "base" << endl; } }; class Derived: public Base { public: void func() { cout << "derived" << endl; } void callFunc() { void (Base::*fp)() = &Base::func; (this->*fp)(); // Derived::func will be called. // In my application I store the pointer for later use, // so I can't simply do Base::func(). } }; In the code above the derived class implementation of func will be called from callFunc. Is there a way I can save a member function pointer that

#include <functional> struct A { int func(int x, int y) { return x+y; } }; int main() { typedef std::function<int(int, int) > Funcp; A a; //Funcp func = std:::bind(&A::func, &a); Funcp func = std::bind(&A::func, a, std::placeholders::_1); return 0; } I am getting errors in both of the above bind functions: error C2825: '_Fty': must be a class or namespace when followed by '::' Where is the syntax error? I am using visual studio 2010 Funcp func = std::bind(&A::func, &a, std::placeholders::_1, std::placeholders::_2); 来源： https://stackoverflow.com/questions/5154116/stdfunction-to-member-function

First of all I have to admit that my programming skills are pretty limited and I took over a (really small) existing C++ OOP project where I try to push my own stuff in. Unfortunately I'm experiencing a problem which goes beyond my knowledge and I hope to find some help here. I'm working with a third party library (which cannot be changed) for grabbing images from a camera and will use some placeholder names here. The third party library has a function "ThirdPartyGrab" to start a continuous live grab and takes a pointer to a function which will be called every time a new frame arrives. So in a

I have an application that needs to run both on WinXP and Vista64. My program requires QueryFullProcessImageName() to work on Vista but not on XP. I try to load QueryFullProcessImageName() (instead of linking statically) via the kernel32.dll so that the same executable can run on both WinXP and Vista. The code that loads it is: //only gets called on vista bool LoadQueryFullProcessImageName() { HMODULE hDLL = LoadLibrary("kernel32.dll"); if (!hDLL) return(0); //Now use pointer to get access to functions defined in DLL fpQueryFullProcessImageName = (LPQueryFullProcessImageName)GetProcAddress

I got an official answer to this question that decltype should not trigger function compilation. In fact decltype on a function that is declared but not defined is legal. Next question, should taking the address of a function trigger the compilation of a function? Take this example : template <typename T> void foo(T&& x) { x.func(); } int main() { auto bar = &foo<int>; } All the compilers I've tested fail with an error like: Request for member func in x , which is of non-class type int But if I just define foo and don't declare it, the code compiles fine. Can someone provide me with an

I'm trying to make some callbacks from member functions and everything was ok until I tried to use a template class derived from 2 classes as callback object when I got the following error: error C2440: 'reinterpret_cast' : Pointers to members have different representations; cannot cast between them This thing signaled me that member function pointers have different representations(doh!) What are these representations? What is the difference between them? Danny Kalev explains this quite nicely : The Underlying Representation of Pointers to Members Although pointers to members behave like