Eroare de compilare: In file included from /usr/include/c++/4.4/algorithm:62, from user.cpp:4: /usr/include/c++/4.4/bits/stl_algo.h: In function ‘const _Tp& std::__median(const _Tp&, const _Tp&, const _Tp&, _Compare) [with _Tp = segment, _Compare = bool (*)(segment&, segment&)]’: /usr/include/c++/4.4/bits/stl_algo.h:2301: instantiated from ‘void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<segment*, std::vector<segment, std::allocator<segment> > >, _Size = int, _Compare = bool (*)(segment&, segment&)]’ /usr/include/c++/4.4/bits/stl_algo.h:5258: instantiated from ‘void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = __gnu_cxx::__normal_iterator<segment*, std::vector<segment, std::allocator<segment> > >, _Compare = bool (*)(segment&, segment&)]’ user.cpp:32: instantiated from here /usr/include/c++/4.4/bits/stl_algo.h:124: error: invalid initialization of reference of type ‘segment&’ from expression of type ‘const segment’ /usr/include/c++/4.4/bits/stl_algo.h:125: error: invalid initialization of reference of type ‘segment&’ from expression of type ‘const segment’ /usr/include/c++/4.4/bits/stl_algo.h:127: error: invalid initialization of reference of type ‘segment&’ from expression of type ‘const segment’ /usr/include/c++/4.4/bits/stl_algo.h:131: error: invalid initialization of reference of type ‘segment&’ from expression of type ‘const segment’ /usr/include/c++/4.4/bits/stl_algo.h:133: error: invalid initialization of reference of type ‘segment&’ from expression of type ‘const segment’