How to debug C++ functor in gdb?

How to debug C++ functor in gdb?

[Peng Yu]

Hi,

I have a test program using functor below.

I set a break point at the line indicated in the comment. Then I call
the following command in gdb. It failed. Is there any way that I can
call the functor _f?

(gdb) p _f(10)
Couldn't find method functor<function<int> >::_f


Thanks,
Peng

#include <functional>

template <typename F>
class functor {
  public:
    functor(const F &f) : _f(f) { }
    typename F::result_type operator()(double x) const { return
_f(static_cast<int>(x)); }//set break point here in gdb
  private:
    F _f;
};

template <typename T>
struct function : public std::unary_function<T, double> {
  double operator()(T x) const { return static_cast<double>(x); }
};

int main() {
  functor<function<int> > g((function<int>()));
  g(1.1);
}

Re: How to debug C++ functor in gdb?

[Andreas Schwab]

"Peng Yu" <pengyu.ut@gmail.com> writes:

> I set a break point at the line indicated in the comment. Then I call
> the following command in gdb. It failed. Is there any way that I can
> call the functor _f?
>
> (gdb) p _f(10)
> Couldn't find method functor<function<int> >::_f

(gdb) p _f.'operator()'(10)
$1 = 10

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: How to debug C++ functor in gdb?

[Peng Yu]

On 10/29/06, Andreas Schwab <schwab@suse.de> wrote:
> "Peng Yu" <pengyu.ut@gmail.com> writes:
>
> > I set a break point at the line indicated in the comment. Then I call
> > the following command in gdb. It failed. Is there any way that I can
> > call the functor _f?
> >
> > (gdb) p _f(10)
> > Couldn't find method functor<function<int> >::_f
>
> (gdb) p _f.'operator()'(10)
> $1 = 10
>
> Andreas.

Hi,

Is it syntax described in the manual somewhere?

Thanks,
Peng

Re: How to debug C++ functor in gdb?

[Andreas Schwab]

"Peng Yu" <pengyu.ut@gmail.com> writes:

> On 10/29/06, Andreas Schwab <schwab@suse.de> wrote:
>> "Peng Yu" <pengyu.ut@gmail.com> writes:
>>
>> > I set a break point at the line indicated in the comment. Then I call
>> > the following command in gdb. It failed. Is there any way that I can
>> > call the functor _f?
>> >
>> > (gdb) p _f(10)
>> > Couldn't find method functor<function<int> >::_f
>>
>> (gdb) p _f.'operator()'(10)
>> $1 = 10
>>
>> Andreas.
>
> Hi,
>
> Is it syntax described in the manual somewhere?

operator() is normal C++ syntax.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."