v1806 Developer Upgrade Guide

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Dictionary input compatibility

Removed deprecated support for compressed/uncompressed as selector names for the writeCompression type. These were deprecated DEC-2009 and now finally removed. If these are encountered, a warning will be emitted

Unknown compression specifier 'compressed', assuming no compression

Update your dictionaries to use a normal switch value:

writeCompression on;
writeCompression off;

Source code incompatibilities

Numerous internal changes have been to several low-level containers for improved memory usage and to provide better guards against memory leaks. Some of the changes may affect the compilation of existing user code.

Compiler define for the API level

The compiler define for the API level is simplified:

#if OPENFOAM < 1806
    ... old code
#endif

The older OPENFOAM_PLUS define is provided (in stdFoam.H) for existing code.

List

The List constructor from two arbitrary iterators has been removed since it was fragile and interfered with constructor resolution. The new ListOps::create factory methods provide robuster and more flexible solutions.

HashTable

Removed const access version of HashTable::operator()(key, default) const since there is a non-const version with an identical signature, which in some cases could lead to the wrong version being called.

Read accessed are now handled more explicitly via the HashTable::lookup(key, default) method.

This helps avoids unintentional insertions.

String construction

Previously it was possible to implicitly create a string from a single character, which could lead to very curious situations.

Both of these would have previously worked:

str.replace('(', '_');     // Sure
str.replace('(', true);    // Compiled, but a bad idea

This constructor is now marked as being explicit, to avoid dubious automatic conversions. This means that some existing code will not compile.

For example, the following

str.replace('(', '_');     // Sure

should be changed to this

str.replace("(", "_");

regExp

The API for matching with groups has changed.

Element 0 now contains the entire match instead of group 1 and element 1 contains the match for group 1.

Additionally, the matches are no longer stored as copies in a List container, but stored by iterator pairs for the matched ranges.

The aligns the behaviour with the C++11 regex conventions in anticipation of a future change to C++11 regex. This is currently not possible due to incomplete coverage with various compilers.

The regExp::results_type now behaves similarly to the C++11 std::smatch type.

• Old:

  List<std::string> mat;
  if (re.match(text, mat))  Info<< "group 1: " << mat[0] << nl;

• New:

  regExp::results_type mat;
  if (re.match(text, mat))  Info<< "group 1: " << mat.str(1) << nl;

Foam::name

The two-parameter form introduced in a previous version has been replaced by word::printf() to avoid ambiguity and clarify the expected output and behaviour.

For example,

word::prinf("index_%05d", idx);

HashTable, HashSet, string::hash

The string::hash function, which is used by HashTable and HashSet now operates on std::string directly, to further eliminate inadvertent automatic conversions.

This means that the following type of code will no longer compile:

HashSet<label>  set;
HashTable<scalar, label> table;

since there is correct way to use a string hash function on a label. This did compile in previous versions (through the automatic conversions), but would have been incorrect and resulted in very slow hash tables.

The easy correction is to use a container with the suitable hasher, e.g.,

labelHashSet  set;
Map<scalar> table;

HashPtrTable, PtrMap

Using an insert() with raw pointers is now disallowed, since a failed insertion , i.e. where the entry already existed, would result in an unmanaged pointer and a potential memory leak.

Change your code to insert() using an autoPtr or else using the set() method with an autoPtr or a raw pointer.

IOobjectList

Similar to potential memory leakage with HashPtrTable.

• IOobjectList::add() now takes an autoPtr instead of an object reference.
• IobjectList::remove() now returns an autoPtr instead of a raw pointer.

stringListOps

Removed direct use of C-string or string, which was previously implicitly converted to a regExp:

findStrings()
subsetStrings()
subsetStrings()
inplaceSubsetStrings()

For most cases, this conversion would be largely unintentional and also less efficient. If the regex is desirable, the caller should invoke it explicitly.

For example,

findStrings(regExp(str), listOfStrings);

Or use one of the more standard keyType, wordRe, wordRes variants instead.

If string is to be used as a plain (non-regex) matcher, the ListOps function should be used:

findIndices(listOfStrings, str);

ListOps namespace change

Relocated some functions into the ListOps namespace for better code isolation and documentation of purpose.

The updated functions also have many more alternative selectors possible and parameter options than previously.

ListOps functions removed

Removed deprecated and unused ListOps functions which were deprecated MAR-2017.

subset(const UList<T>& select, const T& value, const ListType&);
inplaceSubset(const UList<T>& select, const T& value, ListType&);

The subsetList/inplaceSubsetList variants with a unary predicate provide more flexible and robuster solutions.

Removed the deprecated (deprecated MAR-2017) initList methods

initList(const T[mRows]);
initListList(const T[mRows][nColumns]);

These have be replaced by List constructors and std::initializer_list

Remove usage of Xfer class

The Xfer class was a remnant from C++98 code and has now been been removed from the code in favour of using C++11 movable references. This change largely affects internal library use.

A visible change for advanced users is the polyMesh constructor, which now takes movable references, and the polyMesh::resetPrmimitives method, which now takes autoPtr instead.

autoPtr

Was significantly revised and improved. In the course of doing so, the method names for direct, unchecked pointer access were changed:

• renamed rawPtr() to get()
• renamed rawRef() to ref()

The method name get() was chosen for consistency with std::unique_ptr naming. The method name ref() was chosen for similarity with the tmp.

PackedList, PackedBoolList

PackedBoolList has been removed and replaced by the new bitSet class that offers more functionality. In most cases bitSet can be treated as a drop-in replacement.

Compilation of existing code will generally be unaffected and the PackedBoolList name is still available as a compatiblity typedef and header. However, there are some differences of behaviour.

Access to non-existent entries

In previous versions of PackedList and PackedBoolList, the array-like access was treated indirectly. So that code with list[i] created a somewhat large intermediate proxy object. This means that it could be used to query non-existent elements or, when assigned to, it could resize the list and set the value. In some cases this automatic behaviour was convenient, in other cases it could be used inadvertently and cause subtle bugs.

• Old code:

  PackedBoolList items(10);
  
  items[20] = true;    // OK. auto vivifies a new element
  items.get(30);       // OK. lazy evaluation (out-of-bounds) = false
  items.set(40);       // OK. auto vivifies a new element
  if (items[50]) ...   // OK. lazy evaluation (out-of-bounds) = false

• New code:

  bitSet items(10);
  
  items[20] = true;      // Error. Out of bounds.
  items.get(30);         // OK. lazy evaluation (out-of-bounds) = false
  items.set(40);         // OK. auto vivifies a new element
  if (items[50]) ...     // Error. Out of bounds.
  if (items.test(50))... // OK. lazy evaluation (out-of-bounds) = false

For read-only (const) access, the behaviour is similar to previously.

bitSet items(10);

items.get(30);         // OK. lazy evaluation (out-of-bounds) = false
if (items[50]) ...     // OK. lazy evaluation (out-of-bounds) = false
if (items.test(50))... // OK. lazy evaluation (out-of-bounds) = false

Iterators

Iterators for the PackedList class have been removed for performance reasons. The usual forAll macro can still be used.

The PackedBoolList iterators have changed behaviour in bitSet. The regular iterator has been full removed (can use forAll macro as an alternative).

The bitSet const_iterator has changed behaviour. It now only iterates over values that are true, skipping intermediate values. Dereferencing the iterator returns the location.

• Old code:

  PackedBoolList selected(...);
  
  forAllConstIters(selected, iter)
  {
      if (*iter)
      {
          // Value is true, but where am I?
      }
  }
  
  forAll(selected, celli)
  {
      if (selected[celli])
      {
          sumVol += mesh_.cellVolumes()[celli];
      }
  }

• New code:

  bitSet selected(...);
  
  for (const label celli : selected)
  {
      sumVol += mesh_.cellVolumes()[celli];
  }

This change increases usability and improves performance since the iterator internally skips empty elements block-wise with many fewer looping operations.

Applications

foamToTecplot360 has again been removed. It was previously broken, but updated for OpenFOAM-v1612. However, the cryptic API-versioned calls, limited availability of the SDK and lack of adequate testing made proper maintenance very difficult.