Abtract parameter types?

[TheDestroyer]

Hello guys,

I don't know whether this is the right name for what I'm going to ask about. But I see often functions called or implemented in Qt and other programs in a way:

my_function(int)
{
    ...
}

this abstract "int" in the parameter list without variables names I can't understand. How is it used? and what is it? to what extend can it be used? I see it often in slots/signals connect function in Qt!

Any useful simple examples to understand this?

Thank you :)

[writetonsharma]

In connect it is used to tell the type of value a signal will emit and that will be caught by the slot. If the parameter is different than the slot will fail to catch. so for example, this is correct:

connect(buttonsOrientationComboBox, SIGNAL(currentIndexChanged(int)),
            this, SLOT(buttonsOrientationChanged(int)));

but this will fail as the slot will not know the signal type:

connect(buttonsOrientationComboBox, SIGNAL(currentIndexChanged()),
            this, SLOT(buttonsOrientationChanged(int)));

[TheDestroyer]

Thank you for the fast answer!

So this form doesn't have any other use in C++? I mean in standard C++?

[writetonsharma]

I have not seen it anywhere but wait for more replies. :)

[kbw]

I just means that the parameter passed in to the function is unused. Some compilers warn about unused parameters, so its common to leave it unnamed to avoid the warning.

[TheDestroyer]

Thanks guys :D