UIUtilDisp is some strange....

[sunny an]

template <typename ErrorDispatch = ETPrintWarning>
struct UIUtilDisp
{
    template <typename ContainerType, typename UIType>
    static bool Assign(ContainerType *container, UIType *&item,
                       const QString &name, bool *err = NULL)
    {
        if (!container)
        {
            if (err)
                *err |= ErrorDispatch::Container(name);
            else
                ErrorDispatch::Container(name);
            return true;
        }

        item = dynamic_cast<UIType *>(container->GetChild(name));

        if (item)
            return false;
        
        /* from here, item had NULL definitely. Where err value is set from? */

        if (err)
            *err |= ErrorDispatch::Child(container->objectName(), name);
        else
            ErrorDispatch::Child(container->objectName(), name);
        return true;
    }
};

above code snippet is in lib/libmythui/mythuiutls.h

In following codes, event though GetChild?("ex") failed, err get false.
But I think that err should have get true after run UIUtilE::Assign.

bool err = false;
UIUtilE::Assign(this, m_example, "ex", &err);

[stuartm]

Although I'd agree that this code does not read easily, with all the templating etc it's obscure to say the least, the logic appears correct.

if item is null, then we evaluate if (err) (true, err is a pointer not a bool), we then do a OR (|) bit op to *err (address of err, a bool).