Eroare de compilare: /usr/include/c++/4.2/bits/stl_algo.h: In function 'const _Tp& std::__median(const _Tp&, const _Tp&, const _Tp&) [with _Tp = pConcerte]': /usr/include/c++/4.2/bits/stl_algo.h:2758: instantiated from 'void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size) [with _RandomAccessIterator = pConcerte*, _Size = int]' /usr/include/c++/4.2/bits/stl_algo.h:2829: instantiated from 'void std::sort(_RandomAccessIterator, _RandomAccessIterator) [with _RandomAccessIterator = pConcerte*]' user.cpp:90: instantiated from here /usr/include/c++/4.2/bits/stl_algo.h:91: error: no match for 'operator<' in '__a < __b' user.cpp:20: note: candidates are: bool pConcerte::operator<(pConcerte&) /usr/include/c++/4.2/bits/stl_algo.h:92: error: no match for 'operator<' in '__b < __c' user.cpp:20: note: candidates are: bool pConcerte::operator<(pConcerte&) /usr/include/c++/4.2/bits/stl_algo.h:94: error: no match for 'operator<' in '__a < __c' user.cpp:20: note: candidates are: bool pConcerte::operator<(pConcerte&) /usr/include/c++/4.2/bits/stl_algo.h:98: error: no match for 'operator<' in '__a < __c' user.cpp:20: note: candidates are: bool pConcerte::operator<(pConcerte&) /usr/include/c++/4.2/bits/stl_algo.h:100: error: no match for 'operator<' in '__b < __c' user.cpp:20: note: candidates are: bool pConcerte::operator<(pConcerte&)