hline_set
extern int hline_set(const cchar_t *, int);
#define mvhline_set(y,x,cp,n) (move(y,x)?ERR:hline_set(cp,n))
extern int hline_set(const cchar_t *, int);
(move(y, x) ? (cp, n, ERR) : hline_set(cp, n))