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Thread: "ambiguous base" error

  1. #1
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    Default "ambiguous base" error

    Hi,

    I'm porting a co-worker's code to Qt4. It controls a huge vat of great-tasting lemonade. I think great-tasting lemonade should be controlled by a great-looking GUI. That's why I'm going to Qt4.

    It compiles great with Qt3, but when I use Qt4 I get this error:

    lemonDiag.C:590: error: 'QObject' is an ambiguous base of 'CHWController'
    The line causing the problem looks like this:

    Qt Code:
    1. QObject::connect(hwc,SIGNAL(ph_off_balance(double)),temp1A,SLOT(setValue(double)));
    To copy to clipboard, switch view to plain text mode 

    And the constructor looks like this:

    Qt Code:
    1. class CHWController: public QObject, public QThread
    To copy to clipboard, switch view to plain text mode 

    Could the dual inheritance be a problem? Is there a simple fix?
    What should I do?

  2. #2
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    Default Re: "ambiguous base" error

    In Qt4 QThread inherits QObject. In Qt3 it is a really bad idea to mix threads and signals.

  3. The following user says thank you to jacek for this useful post:

    mhoover (13th June 2006)

  4. #3
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    Default Re: "ambiguous base" error

    Oh ... Interesting.

    So could I then declare his class without explicitly inheriting from QObject?

    Qt Code:
    1. class CHWController: public QThread
    To copy to clipboard, switch view to plain text mode 

    Or would a more drastic solution be in order?

  5. #4
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    Default Re: "ambiguous base" error

    Quote Originally Posted by mhoover
    So could I then declare his class without explicitly inheriting from QObject?
    Yes, because QObject is already there.

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