namespace faces {
  enum face {
    normal    = 0x00,
    bold      = 0x01,
    dark      = 0x02,
    uline     = 0x04,
    invert    = 0x07,
    invisible = 0x08,
    cline     = 0x09
  };
}


static inline char* set_face_s(char** buff, size_t &size,
             faces::face face = faces::normal) {
  char* output = *buff;
  uintptr_t offset = 0;
  assert(size > (  1 /* '' */
       + 2 /* "33[" */
       + 1 /* face */
       + 1) /* "m" */
     && "set_face_s::insufficient memory");
  output[0] = '';
  strcat(output,"33[");
  offset += 2;

  if (!face) {
    strcat(output, "0"); // reset everything
    offset+=1;
  }
  if (face) {
    sprintf(output+offset, "%d", face);
  }
  strcat(output,"m");
  offset+=1;
  (*buff) += (offset+1);
  size -= (offset+1);
  return output;
}

void f() {
  char buffer[1024];
  char* arr = buffer;
  size_t bytesLeft = 1024;
  char* c = strcat(set_face_s(&arr, bytesLeft, faces::uline),
                   set_face_s(&arr, bytesLeft, faces::bold))
}

void g() {
  char buffer[1024];
  char* arr = buffer;
  size_t bytesLeft = 1024;
  char* c1 = set_face_s(&arr, bytesLeft, faces::uline);
  char* c2 = strcat(c1, set_face_s(&arr, bytesLeft, faces::bold));
}