Compilare: user.cpp: In member function ‘int ifbuffer::getnr()’: user.cpp:38:31: warning: array subscript has type ‘char’ [-Wchar-subscripts] while ( !isDigit[c] ) ^ user.cpp:41:30: warning: array subscript has type ‘char’ [-Wchar-subscripts] while ( isDigit[c] ) { ^ user.cpp: At global scope: user.cpp:177:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main() { ^ user.cpp: In function ‘int main()’: user.cpp:178:30: warning: deprecated conversion from string constant to ‘char*’ [-Wwrite-strings] ifbuffer fin( "great.in" ); ^ user.cpp: In member function ‘void ifbuffer::refill()’: user.cpp:22:41: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread( text, 1, size, file ); ^