[Boost-users] pimpl and Qt

17 May 2005

      Hi!

I'm having trouble implementing Pimpl idiom with Qt. Look at the following 
code:

class IndispFilterWidget : public QHBox {
    Q_OBJECT
public:
    IndispFilterWidget(QWidget* parent = 0);

private:
    struct Private;
    boost::scoped_ptr<Private> d;
};

struct IndispFilterWidget::Private {
    QIntDict<BrushButton> buttons;
};

IndispFilterWidget::IndispFilterWidget(QWidget* parent)
    : QHBox(parent)
    , d(new Private)
{
}

and see the error:

/usr/include/boost/checked_delete.hpp: In function 'void 
boost::checked_delete(T*) [with T = 
exames::calendario::IndispFilterWidget::Private]':
/usr/include/boost/scoped_ptr.hpp:77:   instantiated from 
'boost::scoped_ptr<T>::~scoped_ptr() [with T = 
exames::calendario::IndispFilterWidget::Private]'
/home/fsousa/projects/GAL/BUILD/modules/exames/calendario/../../../../modules/exames/calendario/IndispFilterWidget.h:31:   
instantiated from here
/usr/include/boost/checked_delete.hpp:32: error: invalid application of 
'sizeof' to incomplete type 'exames::calendario::IndispFilterWidget::Private' 
/usr/include/boost/checked_delete.hpp:32: error: creating array with size zero 
('-0x000000001')
/usr/include/boost/checked_delete.hpp:33: error: invalid application of 
'sizeof' to incomplete type 'exames::calendario::IndispFilterWidget::Private' 
/usr/include/boost/checked_delete.hpp:33: error: creating array with size zero 
('-0x000000001')
/usr/include/boost/checked_delete.hpp:34: warning: possible problem detected 
in invocation of delete operator:
/usr/include/boost/checked_delete.hpp:29: warning: 'x' has incomplete type
/home/fsousa/projects/GAL/BUILD/modules/exames/calendario/../../../../modules/exames/calendario/IndispFilterWidget.h:45: 
warning: forward declaration of 'struct 
exames::calendario::IndispFilterWidget::Private'

If I remove Q_OBJECT macro or add a destructor the code compiles fine. I don't 
have a problem with shared_ptr, only with scoped_ptr.

-- 
Filipe Sousa