Sort mit selbstgeschriebenem Vergleichsfunctor auf vector anwenden

[Pumuckl@work]

Moin moin. Ich hab ein kleines Problem beim Compilieren folgenden Codes, hat jemand Ahnung was da schief läuft?:

#include <algorithm>
#include <functional>
#include <utility>
#include <vector>

struct Chiquadresult
  {
  float period;
  float err_period;
  float amplitude;
  float err_amplitude;
  float magmed;
  float err_magmed;
  float fase;
  float err_fase;
  float chimin;
  float desvstchi;
  float firstmax;
  float errfirstmax;
  int pn; //minimal period searched in
  };

//...

class PerComptor : public binary_function<Chiquadresult,Chiquadresult,bool>
  {
  public:
  bool operator()(const Chiquadresult& lhs, const Chiquadresult& rhs)
    { return (lhs.period < rhs.period); };
  };

//...
int main()
  {
  //...
  vector<Chiquadresult> cqrtempvec();
  //vector wird gefuellt...

  //erstelle Comparator-Objekt:
  PerComptor pc();

  //sortiere den vector nach "period" der Chiquadresult-structs
  sort(cqrtempvec.begin(), cqrtempvec.end(), pc); // Zeile 155, siehe Fehlermeldung
  }

An dieser Stelle spuckt er mir folgende Fehlermeldung (und einige ähnliche mehr):

/usr/include/g++/bits/stl_heap.h: In function `void 
   std::__adjust_heap(_RandomAccessIterator, _Distance, _Distance, _Tp, 
   _Compare) [with _RandomAccessIterator = 
   __gnu_cxx::__normal_iterator<Chiquadresult*, std::vector<Chiquadresult, 
   std::allocator<Chiquadresult> > >, _Distance = int, _Tp = Chiquadresult, 
   _Compare = PerComptor (*)()]':
/usr/include/g++/bits/stl_heap.h:268:   instantiated from `void std::make_heap(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<Chiquadresult*, std::vector<Chiquadresult, std::allocator<Chiquadresult> > >, _Compare = PerComptor (*)()]'
/usr/include/g++/bits/stl_algo.h:2557:   instantiated from `void std::partial_sort(_RandomAccessIter, _RandomAccessIter, _RandomAccessIter, _Compare) [with _RandomAccessIter = __gnu_cxx::__normal_iterator<Chiquadresult*, std::vector<Chiquadresult, std::allocator<Chiquadresult> > >, _Compare = PerComptor (*)()]'
/usr/include/g++/bits/stl_algo.h:2140:   instantiated from `void std::__introsort_loop(_RandomAccessIter, _RandomAccessIter, _Size, _Compare) [with _RandomAccessIter = __gnu_cxx::__normal_iterator<Chiquadresult*, std::vector<Chiquadresult, std::allocator<Chiquadresult> > >, _Size = int, _Compare = PerComptor (*)()]'
/usr/include/g++/bits/stl_algo.h:2211:   instantiated from `void std::sort(_RandomAccessIter, _RandomAccessIter, _Compare) [with _RandomAccessIter = __gnu_cxx::__normal_iterator<Chiquadresult*, std::vector<Chiquadresult, std::allocator<Chiquadresult> > >, _Compare = PerComptor (*)()]'
LC_normal.cpp:155:   instantiated from here
/usr/include/g++/bits/stl_heap.h:187: error: too many arguments to function
/usr/include/g++/bits/stl_heap.h:187: error: could not convert `__comp()' to `
   bool'

[FireFlow]

//erstelle Comparator-Objekt:
  PerComptor pc();

Hier deklarierst du eine Funktion und erstellst kein Objekt.

[pumuckl]

autsch. danke