How to use std::async on a member function?

Question

How can I operate std::async call on a member function?

Example:

class Person{ public:     void sum(int i){         cout << i << endl;     } };  int main(int argc, char **argv) {     Person person;     async(&Person::sum,&person,4); } 

I want to call to sum async.

Person p; call async to p.sum(xxx) 

I didnt figure out if i can do it with std::async. Dont want to use boost. Looking for a one line async call way.

Answer 1

Something like this:

auto f = std::async(&Person::sum, &p, xxx); 

or

auto f = std::async(std::launch::async, &Person::sum, &p, xxx); 

where p is a Person instance and xxx is an int.

This simple demo works with GCC 4.6.3:

#include <future> #include <iostream>  struct Foo {   Foo() : data(0) {}   void sum(int i) { data +=i;}   int data; };  int main() {   Foo foo;   auto f = std::async(&Foo::sum, &foo, 42);   f.get();   std::cout << foo.data << "\n"; }