int overflow(int c) { return log(buf->sputc((char)c), "<< "); }
int underflow() { return buf->sgetc(); }
int uflow() { return log(buf->sbumpc(), ">> "); }
int overflow(int c) { return log(buf->sputc((char)c), "<< "); }
int underflow() { return buf->sgetc(); }
int uflow() { return log(buf->sbumpc(), ">> "); }