Re: How to use specific methods with a generic widget pointer?

[Hubert Figuiere <hub figuiere net>]

On 03/17/2009 10:33 AM, Paulo Flabiano Smorigo wrote:
> Hello,
>
> What can I do to solve the following error? I need to use a different
> kind of pointer?
>
> The code:
> Gtk::ToggleButton btnOK;
> Gtk::Widget *ptrElement = NULL;
>
> ptrElement =&btnOK;
>
> ptrElement->set_active(true);
>
> The error:
> error: ‘class Gtk::Widget’ has no member named ‘set_active’

But why do you want to do that, assigning a pointer to a stack object, 
given that as soon as you leave the scope the pointer will be invalid.

Unlike the other said, you'd better use static_cast<> because at that 
point you do know that ptrElement points to a Gtk::ToggleButton.

And no it can't guess. C++ is a statically typed, which means that it 
needs to know at compile time about the method.

Hub