- some functionality similar to what the standary library <iterator>
provides.
* stdFoam::begin() and stdFoam::end() do type deduction,
which means that many cases it is possible to manage these types
of changes.
For example, when managing a number of indices:
Map<labelHashSet> lookup;
1) Longhand:
for
(
Map<labelHashSet>::const_iterator iter = lookup.begin();
iter != lookup.end();
++iter
)
{ .... }
1b) The same, but wrapped via a macro:
forAllConstIter(Map<labelHashSet>, lookup, iter)
{ .... }
2) Using stdFoam begin/end templates directly
for
(
auto iter = stdFoam::begin(lookup);
iter != stdFoam::end(lookup);
++iter
)
{ .... }
2b) The same, but wrapped via a macro:
forAllConstIters(lookup, iter)
{ .... }
Note that in many cases it is possible to simply use a range-based for.
Eg,
labelList myList;
for (auto val : myList)
{ ... }
for (const auto& val : myList)
{ ... }
These however will not work with any of the OpenFOAM hash-tables,
since the standard C++ concept of an iterator would return a key,value
pair when deferencing the *iter.
The deduction methods also exhibits some slightly odd behaviour with
some PtrLists (needs some more investigation).
- to the referenced object via a method name, which may be clearer
than deferencing the iterator
[key, value] => iter.key(), *iter
[key, value] => iter.key(), iter()
[key, value] => iter.key(), iter.object()
