How to use hash_setS in adjacent_list?
If I define BOOST_HAS_HASH the compiler will generate
"error C2977: 'stdext::hash_set' : too many template arguments".
Unfortunately, MS and SGI/GCC disagree on the definition of ext/hash_set. The SGI implementation takes 4 parameters, MS appears to take 3. Eventually, I plan to migrated to tr1::unordered_set, so this shouldn't be a problem.