function-pointers

I want to pass a function value as a template parameter to a function. Currently the best I managed to do is : template< typename F, F f > void pass() { ... } ...which is used: pass< decltype(&func), &func >(); What I would really like is to have: pass< &func >(); Is there any way to achieve this without macros? Basically to pass both the type and the value at the same time? The compiler obviously has all the information needed for that... The solution must work with variable parameters and return types. The function value is used at compile time, so it cannot be passed as an argument. C++11

I need to declare an array of pointers to functions like so: extern void function1(void); extern void function2(void); ... void (*MESSAGE_HANDLERS[])(void) = { function1, function2, ... }; However, I want the the array to be declared as constant -- both the data in the array and the pointer to the data. Unfortunately, I do not recall where to place the const key-word(s). I'm assuming the actual pointer, MESSAGE_HANDLERS in this case, is already constant because it is declared as an array. On the otherhand, couldn't the function pointers within the array be change at runtime if it is declared

I cannot figure this out: int main() { int (*) (int *) = 5; return 0; } The above assignment compiles with g++ c++11. I know that int (*) (int *) is a pointer to a function that accepts an (int *) as argument and returns an int, but I do not understand how you could equate it to 5. At first I thought it is a function that constantly returns 5 (from my recent learning in F#, probably, haha), then I thought, briefly, that the function pointer points to memory location 5, but that does not work, clearly, and neither does hex values. Thinking that it could be because the function returns an int,

For practice, I'm trying to : Declare fubar to be a pointer to a function that takes a pointer to a char and returns a pointer to an array of 24 elements where each element is a pointer to a struct foo . My logic is: -fubar is a pointer to a function taking a char pointer: (*fubar)(char*) -...returning a pointer to an array of 24 elems of where each elem is a struct foo: (struct foo *)(*fubar)(char*)[24] Is my logic correct? After fixing the syntax error and removing the parentheses around struct foo * , struct foo* (*fubar)(char*)[24] ...the one part that you got wrong is that it actually

I'm trying to learn about Boost functions. I want to pass a Python function to a C++ module wrapped using Boost Python. I followed the example given here and modified it to accept functions that take an input argument and return some output. Here's my code: typedef double (op_t)(double); boost::function<op_t> op; double defaultOperator(double t) { return t; } void setOperator(boost::python::object obj) { op = obj; } double callOperator(double t) { return op(t); } BOOST_PYTHON_MODULE(op1) { op = &defaultOperator; def("setOperator", &setOperator); def("callOperator", &callOperator); } When I try

In the C language, the usual route for function pointers as callbacks from some library is to include a void* pointer for the context of the user: void (*fp)(void* ctx); The allows the library to call the callback with context ctx . Let's say I'm using a library that does not include a context pointer in the callbacks. I will need to have one callback for each context. What is the most portable way to dynamically allocate function pointers in C for providing callbacks? How can I malloc() a function code that can be called from the library? For example: typedef void (*my_fp_t)(char); my_fp_t fp

I'm trying to write a program which creates a class that contains vector of pointers to member functions, with add() and remove() member functions. The code I wrote is - 1 #include <iostream> 2 #include <vector> 3 using namespace std; 4 5 typedef void(*classFuncPtr)(); 6 7 class FunctionVectors 8 { 9 private: 10 vector<classFuncPtr> FunctionPointerVector; 11 public: 12 FunctionVectors(){} 13 void add(classFuncPtr funcPtr); 14 void remove(int index); 15 void run(); 16 void a(){cout<<"a: Why are you calling me?"<<endl;} 17 }; 18 19 void FunctionVectors::add(classFuncPtr funcPtr) 20 { 21