function-pointers

My Event Manager For a event manager I need to store many pointers to functions in a vector to call them when the event is triggered. (I will provide the source code of the EventFunction helper class at the end of this question.) // an event is defined by a string name and a number typedef pair<string, int> EventKey; // EventFunction holds a pointer to a listener function with or without data parameter typedef unordered_map<EventKey, vector<EventFunction>> ListEvent; // stores all events and their listeners ListEvent List; Registering an listener could be done by calling the first or the

I'm having difficulties implementing a generic 'map' function over arrays. I started with the following draft: void MapArray(void * src, void * dest, void * (f)(void *), size_t n, size_t elem) { unsigned int i = 0, j = 0; void * temp = malloc(elem); for(i = 0; i<n, i++) { temp = (f)((char *) src) + i)); for(j = 0; j < elem; j++) { *(((char *) dest) + i) = *(((char *) temp) + i); } } free(temp); } I understand why it's not correct - i'm casting to (char *) before giving it to 'f' - but i'm now demotivated and can't come up with a solution. (I'm doing this in the process of learning C) My

I've always believed that function pointers don't require an ampersand: Do function pointers need an ampersand Yet, every example I've seen of using boost::bind shows one, and my compiler - in most situations - gives a typically inscrutable error message if it's omitted. synchronize(boost::bind(&Device::asyncUpdate , this, "ErrorMessage")); // Works synchronize(boost::bind(Device::asyncUpdate , this, "ErrorMessage")); // Fails Am I wrong in assuming that boost::bind 's first parameter is basically function pointer? Function pointers don't need it, member function pointers do. Device:

The question pretty much says it all. I'm not sure how to do this and haven't come anywhere near anything that works. Here's some example functions: add(int x, int y) { return x+y; } and, mean(int x1, int y1, int x2, int y2) { return (x1 + y1 + x2 + y2) / 4; } So far I've tried using typedef with both, but I can't figure how to make something point to one of either type: typedef int (*mathfunc2)(int x, int y); typedef int (*mathfunc4)(int x1, int y1, int x2, int y2); ????? func_table[2] = {add, mean}; You need to pick a function pointer type to use as a "generic function pointer", use that

Have come across the line of code shown below I think it may be a cast to a function pointer that returns void and takes a void pointer, is that correct? (void (*)(void *))SGENT_1_calc Yes it is correct. I find that not very readable, so I suggest declaring the signature of the function to be pointed: typedef void sigrout_t(void*); I also have the coding convention that types ending with rout_t are such types for functions signatures. You might name it otherwise, since _t is a suffix reserved by Posix latter on I am casting, perhaps to call it like ((sigrout_t*) SGENT_1_calc) (someptr); Yes it