memcpy 函数内部实现

#include <stdio.h>
#include <assert.h>
void* my_memcpy(void* dest, const void* ser, size_t num)
{
	assert(dest && ser);
	void* ret = dest;
	while (num--)//
	{
		*(char*)dest = *(char*)ser;
		dest = (char*)dest + 1;
		ser = (char*)ser + 1;
	}
	return ret;
}
int main()
{
	int arr1[] = { 1,2,3,4,5,6,7 };
	int arr2[10] = {0};
	my_memcpy(arr2, arr1, 4);
    return 0;
}

图片解析说明