[Rcpp-devel] Compilation errors creating qtdensity example (on Mac OS X)

[Paul Johnson]

I'm getting numerous errors when I try to create the RInside qtdensity example.

This is my first experience with Qt so I suspect there's some simple
thing I'm not doing right.

The first two fatal compilation errors I get are:

---
qtdensity.cpp:37:31: error: allocation of incomplete type 'QLineEdit'
    QLineEdit *cmdEntry = new QLineEdit(m_cmd);
                              ^~~~~~~~~
/usr/local/Qt-5.0.2/include/QtWidgets/qabstractspinbox.h:55:7: note: forward
      declaration of 'QLineEdit'
class QLineEdit;
      ^
qtdensity.cpp:38:14: error: no matching member function for call to 'connect'
    QObject::connect(cmdEntry,  SIGNAL(textEdited(QString)), this,...
    ~~~~~~~~~^~~~~~~
/usr/local/Qt-5.0.2/include/QtCore/qobject.h:199:36: note: candidate function
      not viable: cannot convert argument of incomplete type 'QLineEdit *' to
      'const QObject *'
    static QMetaObject::Connection connect(const QObject *sender, const...
---

The fatal errors occur when processing Qt header files, so perhaps I
have a problem with my Qt installation.