- Since 'bool' and 'Switch' use the _identical_ input mechanism
(ie, both accept true/false, on/off, yes/no, none, 1/0), the main
reason to prefer one or the other is the output.
The output for Switch is as text (eg, "true"), whereas for bool
it is label (0 or 1). If the output is required for a dictionary,
Switch may be appropriate. If the output is not required, or is only
used for Pstream exchange, bool can be more appropriate.
- The iterator for a HashSet dereferences directly to its key.
- Eg,
for (const label patchi : patchSet)
{
...
}
vs.
forAllConstIter(labelHashSet, patchSet, iter)
{
const label patchi = iter.key();
...
}
- 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());
}
- both autoPtr and tmp are defined with an implicit construct from
nullptr (but with explicit construct from a pointer to null).
Thus is it safe to use 'nullptr' when returning an empty autoPtr or tmp.
- eliminate iterators from PackedList since they were unused, had
lower performance than direct access and added unneeded complexity.
- eliminate auto-vivify for the PackedList '[] operator.
The set() method provides any required auto-vivification and
removing this ability from the '[]' operator allows for a lower
when accessing the values. Replaced the previous cascade of iterators
with simpler reference class.
PackedBoolList:
- (temporarily) eliminate logic and addition operators since
these contained partially unclear semantics.
- 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.
- more consistent use of PackedBoolList test(), set(), unset() methods
for fewer operation and clearer code. Eg,
if (list.test(index)) ... | if (list[index]) ...
if (!list.test(index)) ... | if (list[index] == 0u) ...
list.set(index); | list[index] = 1u;
list.unset(index); | list[index] = 0u;
- deleted the operator=(const labelUList&) and replaced with a setMany()
method for more clarity about the intended operation and to avoid any
potential inadvertent behaviour.
Improve alignment of its behaviour with std::unique_ptr
- element_type typedef
- release() method - identical to ptr() method
- get() method to get the pointer without checking and without releasing it.
- operator*() for dereferencing
Method name changes
- renamed rawPtr() to get()
- renamed rawRef() to ref(), removed unused const version.
Removed methods/operators
- assignment from a raw pointer was deleted (was rarely used).
Can be convenient, but uncontrolled and potentially unsafe.
Do allow assignment from a literal nullptr though, since this
can never leak (and also corresponds to the unique_ptr API).
Additional methods
- clone() method: forwards to the clone() method of the underlying
data object with argument forwarding.
- reset(autoPtr&&) as an alternative to operator=(autoPtr&&)
STYLE: avoid implicit conversion from autoPtr to object type in many places
- existing implementation has the following:
operator const T&() const { return operator*(); }
which means that the following code works:
autoPtr<mapPolyMesh> map = ...;
updateMesh(*map); // OK: explicit dereferencing
updateMesh(map()); // OK: explicit dereferencing
updateMesh(map); // OK: implicit dereferencing
for clarity it may preferable to avoid the implicit dereferencing
- prefer operator* to operator() when deferenced a return value
so it is clearer that a pointer is involve and not a function call
etc Eg, return *meshPtr_; vs. return meshPtr_();
- use succincter method names that more closely resemble dictionary
and HashTable method names. This improves method name consistency
between classes and also requires less typing effort:
args.found(optName) vs. args.optionFound(optName)
args.readIfPresent(..) vs. args.optionReadIfPresent(..)
...
args.opt<scalar>(optName) vs. args.optionRead<scalar>(optName)
args.read<scalar>(index) vs. args.argRead<scalar>(index)
- the older method names forms have been retained for code compatibility,
but are now deprecated
