void *Memcpy(void *dest, const void *src, size_t count)
{ cout<<"sizeof(dest)是："<<sizeof(dest)<<endl;int bytelen=count/sizeof(dest); /*按CPU位宽拷贝*/int slice=count%sizeof(dest); /*剩余的按字节拷贝*/unsigned int* d = (unsigned int*)dest; unsigned int* s = (unsigned int*)src; if (((int)dest > ((int)src+count)) || (dest < src)) { while (bytelen--) *d++ = *s++; while (slice--) *(char *)d++ = *(char *)s++; } else /* overlap重叠 */ { d = (unsigned int*)((unsigned int)dest + count - 4); /*指针位置从末端开始，注意偏置 */ s = (unsigned int*)((unsigned int)src + count -4); while (bytelen --) *d-- = *s--; d++;s++;char * d1=(char *)d;char * s1=(char *)s;d1--;s1--;while (slice --) *(char *)d1-- = *(char *)s1--; } return dest;
} 
