使用这种swap实现的最大威胁是什么？除了线程安全和差的优化.什么时候失败(反例)？
template<typename T>
void swapViaMemory(T& left,T& right) {
if(&left == &right) { return ; }
unsigned int tSize = sizeof(T);
unsigned char* lPtr = reinterpret_cast<unsigned char*>(&left);
unsigned char* rPtr = reinterpret_cast<unsigned char*>(&right);
for(unsigned int i = 0; i < tSize; ++i) {
*(lPtr + i) ^= *(rPtr + i);
*(rPtr + i) ^= *(lPtr + i);
*(lPtr + i) ^= *(rPtr + i);
}
}
