How to use boost::bind with non-copyable params, for example boost::promise ?
- by zhengxi
Some C++ objects have no copy constructor, but have move constructor.
For example, boost::promise.
How can I bind those objects using their move constructors ?
#include <boost/thread.hpp>
void fullfil_1(boost::promise<int>& prom, int x)
{
prom.set_value(x);
}
boost::function<void()> get_functor()
{
// boost::promise is not copyable, but movable
boost::promise<int> pi;
// compilation error
boost::function<void()> f_set_one = boost::bind(&fullfil_1, pi, 1);
// compilation error as well
boost::function<void()> f_set_one = boost::bind(&fullfil_1, std::move(pi), 1);
// PS. I know, it is possible to bind a pointer to the object instead of
// the object itself. But it is weird solution, in this case I will have
// to take cake about lifetime of the object instead of delegating that to
// boost::bind (by moving object into boost::function object)
//
// weird: pi will be destroyed on leaving the scope
boost::function<void()> f_set_one = boost::bind(&fullfil_1, boost::ref(pi), 1);
return f_set_one;
}
