Compilare: user.cpp: In function ‘int main()’: user.cpp:275:12: warning: variable ‘it’ set but not used [-Wunused-but-set-variable] for(auto it: updt) { ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:60:41: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:28:39: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^