function-pointers

I'm doing a linear genetic programming project, where programs are bred and evolved by means of natural evolution mechanisms. Their "DNA" is basically a container (I've used arrays and vectors successfully) which contain function pointers to a set of functions available. Now, for simple problems, such as mathematical problems, I could use one type-defined function pointer which could point to functions that all return a double and all take as parameters two doubles. Unfortunately this is not very practical. I need to be able to have a container which can have different sorts of function

Possible Duplicate: What will happen when I call a member function on a NULL object pointer? #include <iostream> #include <string> using namespace std; class myClass{ private: int *x, *y, *z; public: myClass(); ~myClass(); void display(); void math(int,int,int); }; void myClass::math(int x,int y,int z){ this->x = new int; this->y = new int; this->z = new int; *this->x = x; *this->y = y; *this->z = z; cout << "result: " << (x*y)+z << endl; } myClass::~myClass(){ delete x; delete y; delete z; } void myClass::display(){ cout << x << y << z << endl; } myClass::myClass(){ x=0; y=0; z=0; } int main(

In python it is valid to make a construction like: def a(): return 0 if a: print "Function object was considered True" else: print "Function object was considered False" I wish to ask what is the logic that a function pointer is evaluated to True. Why was this kind of construction inserted in the language? Martijn Pieters A lot of things evaluate to True in Python. From the documentation on Boolean operators : In the context of Boolean operations, and also when expressions are used by control flow statements, the following values are interpreted as false: False , None , numeric zero of all

I have following code: typedef int (*t_Function) (int x); t_Function Functions[MAX_FUNCTIONS]; int f(int x) { return 0; } But I cannot initialize it properly. If I add following line: Functions[0] = f; then compiler generates following error: prog.c:217: warning: data definition has no type or storage class prog.c:217: error: conflicting types for Functions How to initialize this array of pointers to functions? You should either do it inside a function, where Functions[0] = f; works fine, or with an array initializer: t_Function Functions[MAX_FUNCTIONS] = {f}; For this to work, f (and all

I have a class: class A { void test_func_0(int); void run(); typedef void(A::*test_func_t)(int); struct test_case_t{ test_func_t test_func; } test_case[100]; }; Now I want to call test_func() inside run(): void A::run() { test_case[0].test_func = &test_func_0; test_case[0].*(test_func)(1); } The last line of my code, doesn't work(compile error), no matter what combination I try. Use this: void A::run() { test_case[0].test_func = &A::test_func_0; (this->*(test_case[0].test_func))(1); } Notice that you had 2 errors. The first one was how you formed the member-function-pointer. Note that the only

For example: using namespace std; #include <iostream> void funcOne() { } void funcTwo( int x ) { } int main() { void (*ptrOne)() = funcOne; cout << ptrOne << endl; //prints 1 void (*ptrTwo)( int x ) = funcTwo; cout << ptrTwo << endl; //prints 1 int (*ptrMain)() = main; cout << ptrMain << endl; //prints 1 } Does anyone know the reasoning behind this? At first I thought it was because the functions don't exist in memory since I never call on them, and thus they never get added to the stack. But even the value of a pointer to the main function prints out 1. Function pointers do not implicitly