- naming like std::map::try_emplace(), it behaves like emplace_set()
if there is no element at the given location otherwise a no-op
ENH: reuse existing HashPtrTable 'slot' when setting pointers
- avoids extra HashTable operations
- clearer coding intent. Mark operator() as 'deprecated'
- add bounds checking to get(label) and set(label) methods.
This gives failsafe behaviour for get() that is symmetric with
HashPtrTable, autoPtr etc and aligns the set(label) methods
for UPtrList, PtrList and PtrDynList.
- use top-level PtrList::clone() instead of cloning individual elements
ENH: support HashPtrTable set with refPtr/tmp (flexibility)
- 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.
- naming similarity with autoPtr, unique_ptr and other containers.
For UPtrList derivatives, this is equivalent to the existing
operator(). The read-only variant is also equivalent to the
single-parameter 'set(label)' method.
With PtrList<T> list(...) :
const T* ptr = list.get(10);
if (ptr)
{
ptr->method();
}
vs.
if (list.set(10))
{
list[10].method();
}
For HashPtrTable there is only a read-only variant which is equivalent
to testing for existence and for value.
With HashPtrTable<T> hash(...) :
const T* ptr = list.get("key");
if (ptr)
{
ptr->method();
}
vs.
if (list.found("key"))
{
// Fails on null pointer!!
list["key"].method();
}
Use of get() is largely a matter of taste or local coding requirements
- forwarding like the emplace() method, but overwriting existing
entries as required
- propagate similar changes to HashPtrTable
For example, with HashPtrTable<labelList> table(...) :
With 'insert' semantics
table.emplace("list1", 1000);
vs
if (!table.found("list1"))
{
table.set("list1", new labelList(1000));
}
or
table.insert("list1", autoPtr<labelList>::New(1000));
Note that the last example invokes an unnecessary allocation/deletion
if the insertion is unsuccessful.
With 'set' semantics:
table.emplace_set("list1", 15);
vs
table.set("list1", new labelList(15));
- support move insert/set and emplace insertion.
These adjustments can be used for improved memory efficiency, and
allow hash tables of non-copyable objects (eg, std::unique_ptr).
- extend special HashTable output treatment to include pointer-like
objects such as autoPtr and unique_ptr.
ENH: HashTable::at() method with checking. Fatal if entry does not exist.
- disallow insert() of raw pointers, since a failed insertion
(ie, entry already existed) results in an unmanaged pointer.
Either insert using an autoPtr, or set() with raw pointers or autoPtr.
- IOobjectList::add() now takes an autoPtr instead of an object reference
- IOobjectList::remove() now returns an autoPtr instead of a raw pointer
