Lex Wennmacher writes:
> 
>      char *
>      svis(char *dst, int c, int flag, int nextc, const char *extra);
> 
>      int
>      strsvis(char *dst, const char *src, int flag, const char *extra);
> 
>      int
>      strsvisx(char *dst, const char *src, size_t len, int flag,
>              const char *extra);

Will we see the `unvis' equivalent of these?