Compilare: user.cpp: In function ‘int main()’: user.cpp:172: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:173: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:176: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:179: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In member function ‘int Cuckoo<type>::parse(type) [with type = int]’: user.cpp:109: instantiated from ‘Cuckoo<type>& Cuckoo<type>::operator<(type) [with type = int]’ user.cpp:182: instantiated from here user.cpp:31: warning: suggest parentheses around ‘-’ inside ‘<<’