[Qt-creator] Debugging helper for forward declared classes (PIMPL)

[resurrection at centrum.cz]

And I will answer myself. One needs to use d.putItem instead of d.putValue and then all works like a charm.
______________________________________________________________
> Od: resurrection at centrum.cz
> Komu: "André Pönitz" <apoenitz at t-online.de>, qt-creator at qt-project.org
> Datum: 12.05.2019 17:05
> Předmět: Re: [Qt-creator] Debugging helper for forward declared classes (PIMPL)
>

 Thanks, this works!
  
 I have only one problem with this. When the type of a field is another complex type for which a debugging helper exists (e.g. QString) instead of using that helper for that type it puts there the Python object representation, e.g.: 
  
 def qdump__MyType(d, value):
     address = d.extractPointer(value["d"])
     ptr = d.createValue(address, "void*")
     name = ptr.split("{QString}")
     with Children(d):
         with SubItem(d, "Name"):
             d.putName("Name")
             d.putValue(name)
  
 The value that appears during debugging is:
  
 Value(name='None',type=QString,bsize=None,bpos=None,data=40E3A8DBFE7F0000,address=0x23f1f3888d0)
  
 I can work around this by copying the logic from the particular debugging helper (mine or Qt's) but I would expect it to be picked up automatically or that I could somehow call it myself. I must be missing something yet.
  
 ______________________________________________________________
 > Od: "André Pönitz" <apoenitz at t-online.de>
 > Komu: resurrection at centrum.cz
 > Datum: 12.05.2019 13:50
 > Předmět: Re: [Qt-creator] Debugging helper for forward declared classes (PIMPL)
 >
 On Sun, May 12, 2019 at 12:42:33PM +0200, resurrection at centrum.cz wrote:
 > I have a problem creating a debugging helper for classes that does use only
 > forward-declared data member like when using PIMPL:
 
 > - MyClass.h
 >     struct MyClassPrivate;
 >     class MyClass
 >     {
 >         MyClassPrivate *d;
 >     };
 >  
 > - MyClass.cpp
 >     struct MyClassPrivate
 >     {
 >         int i;
 >     };
 >     //...
 >  
 > And the debugging helper:
 >  
 > def qdump__MyClass(d, value):
 >     with Children(d):
 >         d.putSubItem("Number", value["d"]["i"])
 >
 > Only place when debugging helper for MyClass works is in the implementation file of
 > MyClass.cpp. In all other places the MyClassPrivate is just forward declared type and
 > the pointer to it is completely opaque to the debugging helper engine unless I step into
 > the MyClass.cpp where the type is defined.    I may be asking for the impossible, but is
 > there a way to work around this somehow? 
 
 When you know the layout of the private class, you can direcly operate on that. 
 E.g.  value.split('...') e.g. works similar to Python's  struct.unpack('...')
 
 I actually prefer this approach nowadays for rarely changing types as it does
 not require any debug information for the type, just the address of an instance. 
 
 Andre'