Submitting one problem I had a compilation error with making my own set comparator, although the program had succesfully been compiled by G++(GCC) 4.4.3 and Visual Studio 2008 compilers on my computer. By submitting some test programs I've found that the error is somehow related to the lower/upper_bound method of map and set containers. For instance, the code like this gets a compilation:

#include <set>
using namespace std;

struct Less
{
bool operator()(pair <int,int> a, pair <int,int> b)
  { return a.first < b.first; }
};

set <pair <int,int> , Less> s;
set <pair <int,int>, Less>::iterator it;

int main()
{
        s.insert(make_pair(1,1));
    it = s.lower_bound(make_pair(0,1));
    return 0;
}


The error message is following:

5bf1d001-ac4d-4354-a106-244d4befaf4e
S:\checker\compile\\Vc7\include\xtree(988): error: no instance of function "Less::operator()" matches the argument list and object (the object has cv-qualifiers that prevent a match)
            argument types are: (const std::pair<int, int>, const std::_Tree<std::_Tset_traits<std::pair<int, int>, Less, std::allocator<std::pair<int, int>>, false>>::key_type)
            object type is: const Less
              if (this->comp(_Key(_Pnode), _Keyval))

                  ^
          detected during:
            instantiation of "std::_Tree<_Traits>::_Nodeptr std::_Tree<_Traits>::_Lbound(const std::_Tree<_Traits>::key_type &) const [with _Traits=std::_Tset_traits<std::pair<int, int>, Less, std::allocator<std::pair<int, int>>, false>]" at line 801
            instantiation of "std::_Tree<_Traits>::iterator std::_Tree<_Traits>::lower_bound(const std::_Tree<_Traits>::key_type &) [with _Traits=std::_Tset_traits<std::pair<int, int>, Less, std::allocator<std::pair<int, int>>, false>]" at line 21 of "5bf1d001-ac4d-4354-a106-244d4befaf4e"

compilation aborted for 5bf1d001-ac4d-4354-a106-244d4befaf4e (code 2)


So I think that it makes some STL features unavailable and wish it to be fixed.