function-pointers

I have two functions with variable number and types of arguments double my_func_one(double x, double a, double b, double c) { return x + a + b + c } double my_func_two(double x, double p[], double c) { return x + p[0] + p[1] + c } I want to use a pointer to a function to the functions I defined above based on a some condition getting true e.g. if (true == condition_1) pfunc = my_func_one; else if (true == condition_2) pfunc = my_func_two; // The function that will use the function I passed to it swap_function(a, b, pfunc); My question is, for this scenario, Can I at all define a function

I've been playing around with Rust the past week. I can't seem to figure out how to pass a function that is defined as a parameter when calling the method, and haven't come across any documentation that shows them being used in that fashion. Is it possible to define a function in the parameter list when calling a function in Rust ? This is what I've tried so far... fn main() { // This works thing_to_do(able_to_pass); // Does not work thing_to_do(fn() { println!("found fn in indent position"); }); // Not the same type thing_to_do(|| { println!("mismatched types: expected `fn()` but found `||`")

I'm trying to figure out how to send a function through a channel, and how to avoid extra cloning in order to execute the function at the other end. If I remove the extra cloning operation inside the closure, I get the following error: error: cannot move out of captured outer variable in an 'Fn' closure Ignoring the fact that this code does absolutely nothing, and makes use of a global mutable static Sender<T> , it represents what I'm trying to achieve while giving the proper compiler errors. This code is not meant to be ran , just compiled. use std::ops::DerefMut; use std::sync::{Arc, Mutex};

I remember once seeing a website, which deciphered complex C++ typedefs including function pointers returning function pointers to functions which return an array with … It would turn such definitions into readable English text: »Pointer to function, returning an array of int-pointers, taking a long and a callback function (taking an int) as parameters«. (something along that lines) typedef int * (*f)(long, void (*)(int))[]; Anybody remember that tool/website? Any hints greatly appreciated iceaway I think you are looking for https://cdecl.org/ . You can find the program itself at https:/

I'm using the Visual Studio 11 beta and I'm curious about a compilation error i'm getting storing a std::function object in my class. typedef std::function<void (int, const char*, int, int, const char*)> MyCallback; In my class I have, MyCallback m_callback; This compiles just fine. If I add one more argument to the list it fails. typedef std::function<void (int, const char*, int, int, const char*, int)> MyCallback; The failure is: >c:\program files (x86)\microsoft visual studio 11.0\vc\include\functional(535): error C2027: use of undefined type 'std::_Get_function_impl<_Tx>' 1> with 1> [ 1>

Generally, we use typedef to get alternate names for datatypes. For example -- typedef long int li; // li can be used now in place of long int But, what does the below typedef do? typedef int (*pf) (int, int); Yu Hao typedef int (*pf) (int, int); This means that variables declared with the pf type are pointers to a function which takes two int parameters and returns an int . In other words, you can do something like this: #include <stdio.h> typedef int (*pf)(int,int); int addUp (int a, int b) { return a + b; } int main(void) { pf xyzzy = addUp; printf ("%d\n", xyzzy (19, 23)); return 0; }

Pointers can be declared as pointing to mutable (non-const) data or pointer to constant data. Pointers can be defined to point to a function. My coworkers and I were discussing the use of "const" with pointers and the question came up regarding the use of const with function pointers. Here are some questions: What is the meaning of a pointer to a constant function versus a pointer to a non-constant function? Can a function be const? Can a function be non-const (mutable)? What is the proper (safe) syntax for passing a function pointer? Edit 1: Function pointer syntax typedef void (*Function