Okay then it must be Micro$oft's fault. Some how Visual Studio .Net 2003's C++ compiler has problem with the queue family of class templates. Very gay...

This compiles fine:



Yet, this does not compile:

It could simply be that MSVC 2003 implements deque (and other queue classes) in such a way were you can't use a partially defined types without generating a compile error, by whatever internal rule it uses.

Oh, and Micro$oft. I've never heard that one before. The cleverness has stupefied me to the point where it isn't funny, just tired and cliché. Weird.

Quote:Original post by Tybon
If I have to hold pointers in my priority_queue, how are the comparisons done? Does it compare the pointers (which is not what I want) or the objects themselves?

if you checked documentation you would see that priority_queue is also parameterized by comparator type which defaults to std::less<T> allowing you to provide a custom comparator type be it free/member function or a functor you do something like this:

struct Q_Less {    bool operator()(const Q* const a, const Q* const b) const {             return /* some comparisons */    }};typedef std::priority_queue< Q*, std::vector<Q*>, Q_Less > pq_of_Qs;

Quote:Original post by Tybon
Some how Visual Studio .Net 2003's C++ compiler has problem with the queue family of class templates.

if you actually checked vc++ 2k3's deque you would see what line is giving you problems:

template< class _Ty,	 class _Ax >class deque : public _Deque_val<_Ty, _Ax> {public:    enum { _DEQUESIZ = _DEQUESIZ_VALUE };//..

where _DEQUESIZ_VALUE is defined to be:

#define _DEQUESIZ_VALUE	(sizeof (_Ty) <= 1 ? 16                       : sizeof (_Ty) <= 2 ? 8                       : sizeof (_Ty) <= 4 ? 4                       : sizeof (_Ty) <= 8 ? 2 : 1) /* elements per block (a power of 2) */

There for the type parameter _Ty needs to be fully defined at compile-time regardless of making it class/static member or not.

Either you change what the value of _DEQUESIZ is, or you store (smart) pointers to Q, or you do template specialization for Q, or you download a different implementation of STL (something like STLport), or you try a different container.

If i was you i would go for just storing smart pointers to Q this will give you expected behaviour on all different compiler implementations of STL not just vc++ 2k3.

Thanks for the suggestions snk_kid. At least I now know why the problem is happening and have some options.