C++: Initializing Struct and Setting Function Pointer

c++, function, initialization, pointers, struct

Solution

This is because when you put the function as a member of the class, it will no longer be of the type `float (*)(float)`, but rather, `float (MyClass::*)(float)`.

Look into `std::function` and `std::mem_fn` to solve these problems.

Example:

struct foo {
    float bar(int x, int y) {}
};

// This works
std::function<float(int, int)> func = std::mem_fn(&foo::bar);

Problem

I am trying to initialize a struct with a function pointer, however I am having trouble doing so unless it is done with a global function. The following code works: ``` float tester(float v){ return 2.0f*v; } struct MyClass::Example{ typedef float(*MyFunc)(float); MyFunc NameOfFunc; float DoSomething(float a){ return NameOfFunc(a); } }; struct Example e; e.MyFunc = tester; ``` My problem is whenever I try to do this with the `tester` function as a function in `MyClass` the code no longer works. In other words, I change the tester function to: ``` float MyClass::tester(float v){ return 2.0f*v; } ``` Any and all help is appreciated (including links)! I have tried googling around for the problem but am unsure what to search (I've tried things such as "C++ struct function pointer initialization in class" to no avail)

Original source