2010/11/7 denilsson31 <denilsson31@xxxxxxxxxx>:
> QFile is defined like this:
>
> class QFile {
> [...]
>
> public;
> [...]
>
> virtual void close();
>
> [...]
> };
>
> dbFile is an interface in sense of Java or pure virtual class if you prefer
> and is defined like this :
>
> class dbFile {
>
> public:
>
> [...]
> virtual int close() = 0;
>
> [...]
> };
>
> So, TemporaryDbFile has the duty to implement dbFile's interface with
> QTemporaryFile (derivated from QFile) :
>
> class TemporaryDbFile :public QTemporaryFile, public dbFile
> {
> [...]
>
> 42: int close()
> 44: {
> 45: QTemporaryFile::close();
> 46: return dbFile::ok;
> 47: }
>
> [...]
> }
>
> But in this nice picture, there is a sand grain : the gcc compiler 4.4.0.
> He tells, mockingly :
>
> TemporaryDbFile.h:42:error: conflicting return type specified for 'virtual
> int TemporaryDbFile::close()'
> C:\Qt\2010.03\qt\include\QtCore\..\..\src\corelib\io\qfile.h:148:error:
> overriding 'virtual void QFile::close()'
>
> Have you some tricks for me ?
You can override dbFile::close() in an intermediate class:
class dbFileWrapper : public dbFile
{
protected:
virtual void doClose() = 0;
int close()
{
doClose();
return dbFile::ok;
}
};
class TemporaryDbFile : public QTemporaryFile, public dbFileWrapper
{
void doClose()
{
QTemporaryFile::close();
}
};
Hope this helps.
Dario
