added HashSet::operator[]() const

- can use the same syntax for boolList, PackedBoolList and labelHashSet
    if (myHashedSet[x]) ...
    if (myBoolList[x]) ...
    if (myPackedList[x]) ...

src/OpenFOAM/containers/HashTables/HashSet/HashSet.C

@@ -51,6 +51,13 @@ Foam::HashSet<Key, Hash>::HashSet(const HashTable<AnyType, Key, Hash>& ht)
 
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
+template<class Key, class Hash>
+inline bool Foam::HashSet<Key, Hash>::operator[](const Key& key) const
+{
+    return found(key);
+}
+
+
 template<class Key, class Hash>
 bool Foam::HashSet<Key, Hash>::operator==(const HashSet<Key, Hash>& rhs) const
 {

src/OpenFOAM/containers/HashTables/HashSet/HashSet.H

@@ -133,9 +133,11 @@ public:
             return HashTable<nil, Key, Hash>::insert(key, nil());
         }
 
-
     // Member Operators
 
+        //- Return true if the entry exists, same as found()
+        inline bool operator[](const Key&) const;
+
         //- Equality. Two hashtables are equal when their contents are equal.
         //  Independent of table size or order.
         bool operator==(const HashSet<Key, Hash>&) const;