Eroare de compilare: /tmp/cclaywpL.o: In function `FindSol()': user.cpp:(.text+0xce4): undefined reference to `std::tr1::hash<Package>::operator()(Package) const' /tmp/cclaywpL.o: In function `std::tr1::_Hashtable<Package, std::pair<Package const, int>, std::allocator<std::pair<Package const, int> >, std::_Select1st<std::pair<Package const, int> >, std::equal_to<Package>, std::tr1::hash<Package>, std::tr1::__detail::_Mod_range_hashing, std::tr1::__detail::_Default_ranged_hash, std::tr1::__detail::_Prime_rehash_policy, false, false, true>::_M_rehash(unsigned int)': user.cpp:(.text._ZNSt3tr110_HashtableI7PackageSt4pairIKS1_iESaIS4_ESt10_Select1stIS4_ESt8equal_toIS1_ENS_4hashIS1_EENS_8__detail18_Mod_range_hashingENSC_20_Default_ranged_hashENSC_20_Prime_rehash_policyELb0ELb0ELb1EE9_M_rehashEj[std::tr1::_Hashtable<Package, std::pair<Package const, int>, std::allocator<std::pair<Package const, int> >, std::_Select1st<std::pair<Package const, int> >, std::equal_to<Package>, std::tr1::hash<Package>, std::tr1::__detail::_Mod_range_hashing, std::tr1::__detail::_Default_ranged_hash, std::tr1::__detail::_Prime_rehash_policy, false, false, true>::_M_rehash(unsigned int)]+0xb8): undefined reference to `std::tr1::hash<Package>::operator()(Package) const' /tmp/cclaywpL.o: In function `std::tr1::__detail::_Map_base<Package, std::pair<Package const, int>, std::_Select1st<std::pair<Package const, int> >, true, std::tr1::_Hashtable<Package, std::pair<Package const, int>, std::allocator<std::pair<Package const, int> >, std::_Select1st<std::pair<Package const, int> >, std::equal_to<Package>, std::tr1::hash<Package>, std::tr1::__detail::_Mod_range_hashing, std::tr1::__detail::_Default_ranged_hash, std::tr1::__detail::_Prime_rehash_policy, false, false, true> >::operator[](Package const&)': user.cpp:(.text._ZNSt3tr18__detail9_Map_baseI7PackageSt4pairIKS2_iESt10_Select1stIS5_ELb1ENS_10_HashtableIS2_S5_SaIS5_ES7_St8equal_toIS2_ENS_4hashIS2_EENS0_18_Mod_range_hashingENS0_20_Default_ranged_hashENS0_20_Prime_rehash_policyELb0ELb0ELb1EEEEixERS4_[std::tr1::__detail::_Map_base<Package, std::pair<Package const, int>, std::_Select1st<std::pair<Package const, int> >, true, std::tr1::_Hashtable<Package, std::pair<Package const, int>, std::allocator<std::pair<Package const, int> >, std::_Select1st<std::pair<Package const, int> >, std::equal_to<Package>, std::tr1::hash<Package>, std::tr1::__detail::_Mod_range_hashing, std::tr1::__detail::_Default_ranged_hash, std::tr1::__detail::_Prime_rehash_policy, false, false, true> >::operator[](Package const&)]+0x99): undefined reference to `std::tr1::hash<Package>::operator()(Package) const' collect2: ld returned 1 exit status