Re: [Boost-users] functional/hash: hash_value with context

Boris Mansencal wrote:

std::tr1::unordered_map<point, myType, ptHasher> map_point_to_myType(10, ptHasher(height));

Is there any drawback to do things like that ? Is there any portability issue ?

I can't think of any; this seems to be a good way. For p.y() in 0 .. height-1, you hash function is now "perfect", that is, hash( p1 ) != hash( p2 ) when p1 != p2.