- Hashes trivially scalar types
- For the non scalar types calls unqualified hash_value activating ADL (boost::hash protocol)
- If ADL does not find a viable candidate, a boost::hash direct call is performed via a forward declaration, so that additional candidates are looked up if the user has included boost/container_hash/hash.hpp.
This maintains a high level of compatibility with boost::hash but making Boost.Intrusive independent from Boost.ContainerHash, so that different C++ standard levels can be used and users using different hash functions don't need direct and indirect dependencies brought by Boost.ContainerHash.
