thread/tutorial/factorial.cpp
2006-09-14 23:02:29 +00:00

33 lines
698 B
C++

// Copyright (C) 2001-2003
// William E. Kempf
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#include <boost/thread/thread.hpp>
#include <iostream>
class factorial
{
public:
factorial(int x, int& res) : x(x), res(res) { }
void operator()() { res = calculate(x); }
int result() const { return res; }
private:
int calculate(int x) { return x <= 1 ? 1 : x * calculate(x-1); }
private:
int x;
int& res;
};
int main()
{
int result;
factorial f(10, result);
boost::thread thrd(f);
thrd.join();
std::cout << "10! = " << result << std::endl;
}