-void opt_show_intval_bi(char *buf, size_t len, const int *x);
-void opt_show_longval_bi(char *buf, size_t len, const long *x);
-void opt_show_longlongval_bi(char *buf, size_t len, const long long *x);
-void opt_show_uintval_bi(char *buf, size_t len, const unsigned int *x);
-void opt_show_ulongval_bi(char *buf, size_t len, const unsigned long *x);
-void opt_show_ulonglongval_bi(char *buf, size_t len, const unsigned long long *x);
+bool opt_show_intval_bi(char *buf, size_t len, const int *x);
+bool opt_show_longval_bi(char *buf, size_t len, const long *x);
+bool opt_show_longlongval_bi(char *buf, size_t len, const long long *x);
+bool opt_show_uintval_bi(char *buf, size_t len, const unsigned int *x);
+bool opt_show_ulongval_bi(char *buf, size_t len, const unsigned long *x);
+bool opt_show_ulonglongval_bi(char *buf, size_t len, const unsigned long long *x);