I noticed that Loki for MSVC6 doesn't compile with
STLport (www.stlport.org) due to std::lower_bound()
being used without a comparator. I don't see why this
change was made, because to my knowledge
std::lower_bound() is correctly implemented in MSVC6's
So here's a patch which makes Loki compile on MSVC6
with and without STLport.