Question

How can I iterate over a tuple (using C++11)? I tried the following:

for(int i=0; i<std::tuple_size<T...>::value; ++i) 
  std::get<i>(my_tuple).do_sth();

but this doesn’t work:

Error 1: sorry, unimplemented: cannot expand ‘Listener …’ into a fixed-length argument list.
Error 2: i cannot appear in a constant expression.

So, how do I correctly iterate over the elements of a tuple?

Answer 1

Boost.Fusion is a possibility:

Untested example:

struct DoSomething
{
    template<typename T>
    void operator()(T& t) const
    {
        t.do_sth();
    }
};

tuple<....> t = ...;
boost::fusion::for_each(t, DoSomething());