Compilare: main.cpp: In member function 'InParser& InParser::operator>>(int&)': main.cpp:33:9: warning: variable 'sgn' set but not used [-Wunused-but-set-variable] int sgn = 1; ^~~ main.cpp: In member function 'char InParser::read_ch()': main.cpp:20:33: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, 4096, file); ^