[Boost-users] Tuple access on Solaris

From: darren.gilbert_at_[hidden]
Date: 2004-12-20 18:19:55

Hello,

I was using the boost tuples library (from boost 1.31) to create a cache key. However, the Solaris compiler (SUNWspro v6.2.p1) complained when I tried to access the last element in the tuple. My class looked something like this:

typedef enum result_type_id {
        ...
} ResultTypeID;

class ParamStateKey;

class Cache
{
        typedef boost::tuple<ParamStateKey, ResultTypeID, int, int, int> key_type;

        // cache implementation
        ...

        // some helper functions defined to hide the boost::tuple interface
        static ParamStateKey &GetState(key_type &k) { return boost::tuples::get<0>(k); }
        static ResultTypeID &GetGreek(key_type &k) { return boost::tuples::get<1>(k); }
        static int &GetProduct(key_type &k) { return boost::tuples::get<2>(k); }
        static int &GetSubpage(key_type &k) { return boost::tuples::get<3>(k); }
        static int &GetBucket(key_type &k) { return boost::tuples::get<4>(k); }

        static key_type MakeKey(const ParamStateKey &psk, ResultTypeID r, int p1, int p2, int bkt)
        {
                return boost::tuples::make_tuple(psk, r, p1, p2, bkt);
        }
};

The solaris compiler complained whenever I tried to call Cache::GetBucket() with the following error:
"../../../../incl/3rd/boost/tuple/detail/tuple_basic.hpp", line 105: Error: Could not find a match for boost::tuples::detail::get_class<0>::get<boost::tuples::detail::get_class<0>::RET, boost::tuples::detail::get_class<0>::HT, boost::tuples::detail::get_class<0>::TT>(boost::tuples::cons<int, boost::tuples::null_type>).
"../../../../incl/3rd/boost/tuple/detail/tuple_basic.hpp", line 105:     Where: While instantiating "static boost::tuples::detail::get_class<1>::get<int&, int, boost::tuples::cons<int, boost::tuples::null_type>>(boost::tuples::cons<int, boost::tuples::cons<int, boost::tuples::null_type>>&)".
"../../../../incl/3rd/boost/tuple/detail/tuple_basic.hpp", line 105:     Where: Instantiated from non-template code.

Firstly, I have no way of deciphering that error message. Through trial and error, I found that removing the GetBucket() calls solved the problem. However, I needed these calls. I reasoned that since the other helper functions worked, it was a problem accessing the last element of the tuple. So I created a dummy entry in the tuple and redefined my typedef:
        typedef boost::tuple<ParamStateKey, ResultTypeID, int, int, int, int> key_type;

This work-around is fine, so this is not an urgent problem. But it seems like this should not be necessary.

________________________________________
Darren Gilbert
Associate Director 
UBS - Equities Quantitative Strategies
Phone: [phone]

Stein's law: "When a trend cannot continue it will stop."
         -- Herb Stein, Chairman of the Council of Economic Advisors under Nixon 

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