- additional dummy template parameter to assist with supporting
derived classes. Currently just used for string types, but can be
extended.
- provide hash specialization for various integer types.
Removes the need for any forwarding.
- change default hasher for HashSet/HashTable from 'string::hash'
to `Hash<Key>`. This avoids questionable hashing calls and/or
avoids compiler resolution problems.
For example,
HashSet<label>::hasher and labelHashSet::hasher now both properly
map to Hash<label> whereas previously HashSet<label> would have
persistently mapped to string::hash, which was incorrect.
- standardize internal hashing functors.
Functor name is 'hasher', as per STL set/map and the OpenFOAM
HashSet/HashTable definitions.
Older code had a local templated name, which added unnecessary
clutter and the template parameter was always defaulted.
For example,
Old: `FixedList<label, 3>::Hash<>()`
New: `FixedList<label, 3>::hasher()`
Unchanged: `labelHashSet::hasher()`
Existing `Hash<>` functor namings are still supported,
but deprecated.
- define hasher and Hash specialization for bitSet and PackedList
- add symmetric hasher for 'face'.
Starts with lowest vertex value and walks in the direction
of the next lowest value. This ensures that the hash code is
independent of face orientation and face rotation.
NB:
- some of keys for multiphase handling (eg, phasePairKey)
still use yet another function naming: `hash` and `symmHash`.
This will be targeted for alignment in the future.
- If the underlying type is contiguous, FixedList hashes its storage directly.
- Drop labelPairHash (non-commutative) from fvMeshDistribute since
FixedList::Hash does the right thing anyhow.
- Hash<edge> specialization is commutative, without multiplication.
- Hash<triFace> specialization kept multiplication (but now uLabel).
There's not much point optimizing it, since it's not used much anyhow.
Misc. changes
- added StaticAssert to NamedEnum.H
- label.H / uLabel.H : define FOAM_LABEL_MAX, FOAM_ULABEL_MAX with the
values finally used for the storage. These can be useful for pre-processor
checks elsewhere (although I stopped needing them in the meantime).
- not much speed difference between SuperFastHash and Jenkin's lookup3 but
both are 5-10% faster than what is currently implemented in Foam::string,
albeit inlining probably helps there.
- TODO: integration with existing infrastructure
