C语言memcpy +memmove实现

memcpy适用于不重叠场景

void* my_memcpy(void * dest, void * src, size_t count)
{
	void * addr = dest;
	while (count--)
	{
		*(char*)dest = *(char*)src;
		dest = (char*)dest + 1;
		src = (char*)src + 1;
	}

	return addr;
}
int arr1[] = { 1,2,3,4,5,6,7,8,9,10 };
	int arr2[20] = { 0 };
	my_memcpy(arr2, arr1, 40);
	for (int i = 0; i < 20; i++)
	{
		printf("%d ", arr2[i]);
	}
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memmove适用于重叠场景(画图，区分前后拷贝顺序)

void* my_memmove(void * dest, const void * src, size_t count)
{
	void * addr = dest;
	if (dest < src)
	{
		//前--->后
		while (count--)
		{
			*(char*)dest = *(char*)src;
			dest = (char*)dest + 1;
			src = (char*)src + 1;
		}
	}
	else
	{
		//后--->前
		while (count--)
		{
			*((char*)dest + count) = *((char*)src + count);
		}
	}
	return addr;
}
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