Re: [Boost-users] [boost-users] [parameter] Error using positional arguments

Cromwell Enage writes:

MinGW reports: 'static const T& boost::random::detail::ptr_helper::ref(const T&) [with T = const boost::mt19937]' and 'static T& boost::random::detail::ptr_helper::ref(T&) [with T = const boost::mt19937]' cannot be overloaded

When I wrap boost::ref around rng, the program runs fine.

I'm curious as to why I get this error only when specifying positional arguments. Have I run afoul of something fundamental, such as the forwarding problem?

I take it back; I'm pretty sure this has nothing to do with forwarding. On what line of *your code* does that error appear? I bet it actually appears in the random library. Thus, I bet this has nothing whatever to do with the parameter library. I suggest you reduce your problem to the minimal example that reproduces the problem. But first I suggest you make rng const in main and see what happens. I bet you get the same error. Remember, positional arguments are passed by const& unless you use ref(). -- Dave Abrahams Boost Consulting www.boost-consulting.com