title: C++ atoi with unsigned char
body: <p>I got an unsigned char with the value of 1, I need to put this in a string like "1".
  But if I try to put this directly into a stringstream it will get the value of char(1) and I need it to be "1".
  I know that if I can get this into the function atoi it will return the "1" value.
  But I tried to cast it to char and put it in the atoi function, but it throws an exception.
  Already tried to put it in a string and them cast c_str() into atoi function, but without success yet.
  If someone can help me I'll apreciate.</p>