C语言：strncat函数的实现

#define _CRT_SECURE_NO_WARNINGS//strncat
#include<assert.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
 char* my_strncat( char*dest, const char* str, int count)
{
 assert(dest != NULL&&str != NULL);
 char* ret = dest;
 while (*++dest != '\0');
 while (count--&&(*dest++ = *str++))
 {
  
 }
 if (count > 0)
 {
  *dest++ = '\0';
 }
 return ret;
}
int main()
{
 char arr1[20] = "abcdef";
 char arr2[10] = "fuck";
 printf("%s", my_strncat(arr1, arr2, 8));
 system("pause");
 return 0;
}