ref: eb52c928b122d6bf4d1c9f8ea7460f3640658c43
dir: /sys/src/libString/s_terminate.c/
#include <u.h>
#include <libc.h>
#include "String.h"
void
s_terminate(String *s)
{
if(s->ref > 1)
sysfatal("can't s_terminate a shared string");
if (s->ptr >= s->end)
s_grow(s, 1);
*s->ptr = 0;
}