[graph] king ordering: get rid of "comparison between signed and unsigned" warning

This patch allows to get rid of the "comparison between signed and unsigned" warning, issued by gcc 3.4.4 at -Wall. I'm not sure of the correctness of the (int)Qptr->size() cast. Regards, Marco Morandini --- /home/marco/Programmi/boost_1_33_0/boost/graph/king_ordering.hpp 2005-09-06 19:20:56.000000000 +0200 +++ king_ordering.hpp 2005-09-08 13:55:10.000000000 +0200 @@ -63,7 +63,7 @@ //heap the vertices already there std::make_heap(rbegin, rend, boost::bind<bool>(comp, _2, _1)); - int i = 0; + typename Buffer::size_type i = 0; for(i = index_begin; i != Qptr->size(); ++i){ colors[get(vertex_map, (*Qptr)[i])] = 1; @@ -168,7 +168,7 @@ int parent_location = Qptr->size() - heap_parent_location; bool valid = (heap_parent_location != 0 && child_location > index_begin + offset && - parent_location < Qptr->size()); + parent_location < (int)Qptr->size()); while(valid && comp((*Qptr)[child_location], (*Qptr)[parent_location])){