These functions dynamic cast a reference to a type, and return a null
object reference if the cast fails. The standard dynamicCast and refCast
functions, by contrast, throw an error if the cast fails.
Topology change occurs before the time-increment and hence the oldest time
field (old-time in the case of 1st order time schemes, old-old-time in the case
of 2nd-order time schemes) is not actually needed as it is replaced by the
current time-field after time-increment so there is no purpose to mapping this
field. However, it is necessary to keep track of the existence of the
oldest-time field to ensure the correct number of old-time fields are cached for
the time-scheme. This development allows fvMesh to delete the redundant
oldest-time fields in such a manner that GeometricField can reinstate them
correctly after time-increment which is more efficient and more reliable than
attempting to map them and done previously.
Additionally fvMesh movement, which occurs after time-increment, now ensure all
old-time fields are up-to-date before NCC stitcher mapping so that both fields
and their old-time values are mapped consistently. This removes the need for
old-time field caching calls in MapGeometricFields, fvMeshAdder and
fvMeshStitcher, thus simplifying the code and improving maintainability.
Currently these deleted function declarations are still in the private section
of the class declarations but will be moved by hand to the public section over
time as this is too complex to automate reliably.
Replaced all uses of complex Xfer class with C++11 "move" constructors and
assignment operators. Removed the now redundant Xfer class.
This substantial changes improves consistency between OpenFOAM and the C++11 STL
containers and algorithms, reduces memory allocation and copy overhead when
returning containers from functions and simplifies maintenance of the core
libraries significantly.
