VTK/Wrapping Special Types

There are some very useful classes in VTK that are not derived from vtkObjectBase and are therefore not wrapped. Some, like vtkTimeStamp, are trivial classes. Others, like vtkVariant, are more comprehensive. The vtkStdString isn't wrapped, but is coerced to "const char *" by the wrappers in a manner that can leave dangling references to temporary objects.

State of the code

The wrapper generator code is a mess of hexidecimal literals, static variables, and badly-named functions. It should be updated to VTK code standards, in both the front-end and the back-end. This process has been started for vtkWrapPython.c through the addition of vtkParseType.h, which defines useful macros for use by the wrapper code.

Status (30 April 2010)

For python, vtkVariant and vtkTimeStamp are both automatically wrapped. There is an issue with constructors for vtkVariant that still needs to be fixed. The wrapper code tries out the various constructor signatures in order until one is able to use the constructor arguments. Because the "char" constructor is tried first, any attempt to make a "double" or "int" variant results in the creation of a "char" variant instead. Creating a variant from a string or a vtkObject works fine, though. Storing variants in a vtkVariantArray also works.

A problem was found with the parser: the leading "~" of the destructor signature is thrown away by the parser, so the destructor isn't distinguishable from a constructor.