Compilare: user.cpp: In function ‘void reteta()’: user.cpp:16:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos < buff.size() && buff[pos] != ')') { ^ user.cpp:29:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos < buff.size() && buff[pos] >= '0' && buff[pos] <= '9') ^ user.cpp:38:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos < buff.size() && buff[pos] == ' ') ^ user.cpp:42:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos < buff.size() && buff[pos] >= '0' && buff[pos] <= '9') ^