- the values from non-overlapping blocks were simply ignored,
which meant that ('111111111111' & '111111') would not mask out
the unset values at all.
- similar oddities in other operations (|=, ^= etc)
where the original implementation tried hard to avoid touching the
sizing at all, but now better resolved as follows:
- '|=' : Set may grow to accommodate new 'on' bits.
- '^=' : Set may grow to accommodate new 'on' bits.
- '-=' : Never changes the original set size.
- '&=' : Never changes the original set size.
Non-overlapping elements are considered 'off'.
These definitions are consistent with HashSet behaviour
and also ensures that (a & b) == (b & a)
ENH: improve short-circuiting within bitSet ops
- in a few places can optimise by checking for none() instead of
empty() and avoid unnecessary block operations.
ENH: added bitSet::resize_last() method
- as the name says: resizes to the last bit set.
A friendlier way of writing `resize(find_last()+1)`
- additional default construct
- add explicit zero-size constructor for ITstream.
For tagged dispatching, without ambiguity
- elminate mandatory name for parsing versions.
This makes it easier to use ITstream, IStringStream, UListStream
interchangeable.
- the NullObject singleton can also be cast to a bitSet
(sufficient size and bit-pattern). Useful for places that
need to hold a reference on construction
- improves backward compatibility and more naming consistency.
Retain setMany(iter1, iter2) to avoid ambiguity with the
PackedList::set(index, value) method.
For example, with some HashTable or Map container of models
{ model0 => 1, model1 => 4, model2 => 5, model3 => 12, model4 => 15, }
specify the remapping
Map<label> mapper({{1, 3}, {2, 6}, {3, 12}, {5, 8}});
inplaceMapValue(mapper, models) then yields
{ model0 => 3, model1 => 4, model2 => 8, model3 => 12, model4 => 15, }
--
ENH: extend bitSet::count() to optionally count unset bits instead.
--
ENH: BitOps compatibility methods for boolList.
- These ease coding that uses a boolList instead of bitSet and use
short-circuit logic when possible.
Eg, when 'bitset' and 'bools' contain the same information
bitset.count() <-> BitOps::count(bools)
bitset.all() <-> BitOps::all(bools)
bitset.any() <-> BitOps::any(bools)
bitset.none() <-> BitOps::none(bools)
These methods can then be used directly in parameters or in logic.
Eg,
returnReduce(bitset.any(), orOp<bool>());
returnReduce(BitOps::any(bools), orOp<bool>());
if (BitOps::any(bools)) ...
- The bitSet class replaces the old PackedBoolList class.
The redesign provides better block-wise access and reduced method
calls. This helps both in cases where the bitSet may be relatively
sparse, and in cases where advantage of contiguous operations can be
made. This makes it easier to work with a bitSet as top-level object.
In addition to the previously available count() method to determine
if a bitSet is being used, now have simpler queries:
- all() - true if all bits in the addressable range are empty
- any() - true if any bits are set at all.
- none() - true if no bits are set.
These are faster than count() and allow early termination.
The new test() method tests the value of a single bit position and
returns a bool without any ambiguity caused by the return type
(like the get() method), nor the const/non-const access (like
operator[] has). The name corresponds to what std::bitset uses.
The new find_first(), find_last(), find_next() methods provide a faster
means of searching for bits that are set.
This can be especially useful when using a bitSet to control an
conditional:
OLD (with macro):
forAll(selected, celli)
{
if (selected[celli])
{
sumVol += mesh_.cellVolumes()[celli];
}
}
NEW (with const_iterator):
for (const label celli : selected)
{
sumVol += mesh_.cellVolumes()[celli];
}
or manually
for
(
label celli = selected.find_first();
celli != -1;
celli = selected.find_next()
)
{
sumVol += mesh_.cellVolumes()[celli];
}
- When marking up contiguous parts of a bitset, an interval can be
represented more efficiently as a labelRange of start/size.
For example,
OLD:
if (isA<processorPolyPatch>(pp))
{
forAll(pp, i)
{
ignoreFaces.set(i);
}
}
NEW:
if (isA<processorPolyPatch>(pp))
{
ignoreFaces.set(pp.range());
}
