- unfriend HashSet, HashTable IO operators
- global min(), max(), minMax() functions taking a labelHashSet and an
optional limit. For example,
labelHashSet set = ...;
Info<< "min is " << min(set) << nl;
Info<< "max (non-negative) " << max(set, 0) << nl;
- make HashTable iterator '->' dereferencing more consistent by also
supporting non-pointer types as well.
- read HashTable values in-situ to avoid copying
- can be used as a more natural test on the iterator.
For example, with
HashTable<..> table;
auto iter = table.find(...);
Following are now all equivalent:
1. if (iter != table.end()) ...
2. if (iter.found()) ...
3. if (iter) ...
- improves backward compatibility and more naming consistency.
Retain setMany(iter1, iter2) to avoid ambiguity with the
PackedList::set(index, value) method.
- relocated HashSetPlusEqOp and HashTablePlusEqOp to
HashSetOps::plusEqOp and HashTableOps::plusEqOp, respectively
- additional functions for converting between a labelHashSet
and a PackedBoolList or List<bool>:
From lists selections to labelHashSet indices:
HashSetOps::used(const PackedBoolList&);
HashSetOps::used(const UList<bool>&);
From labelHashSet to list forms:
PackedBoolList bitset(const labelHashSet&);
List<bool> bools(const labelHashSet&);
- Eg instead of using labelHashSet, used HashSet<label> which uses
the string::hash for hashing. Other places inadvertently using the
string::hash instead of Hash<label> for hashing.
STYLE: use Map<..> instead of HashTable<.., label, Hash<label>>
- reduces clutter
- the zero::null and one::null sub-classes add an additional null
output adapter.
The function of the nil class (special-purpose class only used for
HashSet) is now taken by zero::null.
- improve functional compatibility with DynList (remove methods)
* eg, remove an element from any position in a DynamicList
* reduce the number of template parameters
* remove/subset regions of DynamicList
- propagate Swap template specializations for lists, hashtables
- move construct/assignment to various containers.
- add find/found methods for FixedList and UList for a more succinct
(and clearer?) usage than the equivalent global findIndex() function.
- simplify List_FOR_ALL loops
- lookup(): with a default value (const access)
For example,
Map<label> something;
value = something.lookup(key, -1);
being equivalent to the following:
Map<label> something;
value = -1; // bad value
if (something.found(key))
{
value = something[key];
}
except that lookup also makes it convenient to handle const references.
Eg,
const labelList& ids = someHash.lookup(key, labelList());
- For consistency, provide a two parameter HashTable '()' operator.
The lookup() method is, however, normally preferable when
const-only access is to be ensured.
- retain(): the counterpart to erase(), it only retains entries
corresponding to the listed keys.
For example,
HashTable<someType> largeCache;
wordHashSet preserve = ...;
largeCache.retain(preserve);
being roughly equivalent to the following two-stage process,
but with reduced overhead and typing, and fewer potential mistakes.
HashTable<someType> largeCache;
wordHashSet preserve = ...;
{
wordHashSet cull(largeCache.toc()); // all keys
cull.erase(preserve); // except those to preserve
largeCache.erase(cull); //
}
The HashSet &= operator and retain() are functionally equivalent,
but retain() also works with dissimilar value types.
- provide key_iterator/const_key_iterator for all hashes,
reuse directly for HashSet as iterator/const_iterator, respectively.
- additional keys() method for HashTable that returns a wrapped to
a pair of begin/end const_iterators with additional size/empty
information that allows these to be used directly by anything else
expecting things with begin/end/size. Unfortunately does not yet
work with std::distance().
Example,
for (auto& k : labelHashTable.keys())
{
...
}
- make construct from UList explicit and provide corresponding
assignment operator.
- add construct,insert,set,assignment from FixedList.
This is convenient when dealing with things like edges or triFaces.
- explicitly mention the value-initialized status for the operator().
This means that the following code will properly use an initialized
zero.
HashTable<label> regionCount;
if (...)
regionCount("region1")++;
... and also this;
if (regionCount("something") > 0)
{
...
}
Note that the OpenFOAM HashTable uses operator[] to provide read and
write access to *existing* entries and will provoke a FatalError if
the entry does not exist.
The operator() provides write access to *existing* entries or will
create the new entry as required.
The STL hashes use operator[] for this purpose.
- makes it easier to use as a wordHashSet replacement for situations
where we want to avoid duplicates but retain the input order.
- support construction from HashTable, which means it works like the
HashTable::sortedToc but with its own hashing for these keys.
- expose rehash() method for the user. There is normally no need for
using it directly, but also no reason to lock it away as private.
DynamicList
-----------
- construction, assignment and append
HashSet
-------
- construction, insert, set.
- assignment will use the implicit List constructor
hashedWordList
--------------
- construction, assignment
- additional sort() and uniq() methods.
- Readonly access to HashTable information via lookup() method.
- NB: could avoid 'const char**' constructors in the future
