#include "rune.h"
#include "mbstring.h"

char8_t *
(u8chk)(const char8_t *s, size_t n)
{
	while (n) {
		rune ch;
		int m = u8tor(&ch, s);

		if (ch == RUNE_ERROR)
			return (char8_t *)s;
		n -= m;
		s += m;
	}

	return nullptr;
}