How to call a template class from a Qt designer class

Asked Mar 28 '17 at 06:26

Active Mar 28 '17 at 06:28

Viewed 14 times

I have created a template class as following. I am new to this template concept.

template<class T>
class tem_class
{

private:
    T obj;
public:
    tem_class();
    void set_values(T x);
    T disp_fun();

};

Then I tried to invoke this class in Widget class.

void Widget::on_pushButton_clicked()
    {
       int a,b;
        a=5;
        tem_class<int> obj2 ;
        obj2.set_values(a);
        b = obj2.disp_fun();
    }

But I am getting following errors. error: undefined reference to tem_class<int>::tem_class() error: undefined reference totem_class::set_values(int) error: undefined reference to `tem_class::disp_fun() error: collect2: ld returned 1 exit status

edited Mar 28 '17 at 06:28

SingerOfTheFall

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asked Mar 28 '17 at 06:26

Div

1

Where are the definitions of `tem_class()`, `set_values()` and `disp_func()`? – SingerOfTheFall Mar 28 '17 at 06:28
template tem_class::tem_class() { } template void tem_class::set_values(T x) { obj = x; } template T tem_class::disp_fun() { return obj; } – Div Mar 28 '17 at 06:29
I mean where are they physically defined - you haven't placed them into a cpp file, have you? – SingerOfTheFall Mar 28 '17 at 06:30
yeah.in cpp file – Div Mar 28 '17 at 06:32
in that case that is your problem. Basically move them into the .h file and you should be fine. The dupe I linked has some additional information about defining template members. – SingerOfTheFall Mar 28 '17 at 06:34
ok..I understood.now I palced defintion in .h file. Thanks – Div Mar 28 '17 at 06:34

How to call a template class from a Qt designer class

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