以二进制格式输出对象

以二进制格式输出对象基本思路是直接将对象的内存数值以二进制的格式输出，但是如何获取对象内存的二进制结构 o m9zb&{tu  
是关键。解决方法是通过位操作找出对象内存的每一个bit的值。并把该方法封装成一个迭代器。 oY Y?`<N#  
要注意的问题是位操作符只能对整数类型进行操作，为了对所有类型的对象都有效，必须将对 fu 0]BdM  
象当作char数组来处理。 !.\-l2f  
template<class Container> {jVEstP  
class bit_iterator : public std::iterator<bidirectional_iterator_tag, j\SvfZ0"  
void, void> Y9^;TQ+#  
{ xn1=@0 a  
public: ZDffR:An  
explicit bit_iterator(Container& c) : m_container(&c) Km/#\$|}  
{ nG Bjxhl  
m_size = 8*sizeof(Container); yex4A)n9"'  
m_index = 0; R8"qDj  
} H!6nIS9yxt  
explicit bit_iterator() : m_container(0) V'n4iM  
{ ZP*(ZU@j=Z  
m_size = 8*sizeof(Container); PO1|l-v<Yq  
m_index = m_size; )o51QgPy  
} #21t8  
bool operator* () 3/d`s0O  
{ $K-od3h4=  
char mask = 1; r*Iu6  
char* pc = (char*)m_container; @xu/&pbI  
int i   = (m_size-m_index-1)/8; *21foBfqh  
int off   = (m_size-m_index-1)%8; b&iJui"7k  
mask <<=off; \9FWH}|  
return pc & mask; Y\cQ"9  
} 8y$c\Eu(mF  
bit_iterator<Container>& operator++() xNLvK:@0p  
{ IgxZ_2hO  
m_index++; (A<'{J#5,  
return *this; (bT3 r_  
} iRwlK5(&  
bit_iterator<Container>& operator++(int) F@C^nX9  
{ A]x'!qa@=  
m_index++; TOUP.,f/!  
return *this; \7l%@  
} &uX|Ksq  
bool operator==(bit_iterator<Container>& bitIt) cwK+{*ZH/
 
{ ;`p!/9il  
return m_index == bitIt.m_index; %+Az X  
} o>G^)aRa  
bool operator!=(bit_iterator<Container>& bitIt) /C: rr_4=  
{ FXF#v>&  
return !(*this == bitIt); >R&=mo~  
} N7}Y\1-8  
protected: cbHb!Lbg  
Container* m_container; ueimTXk  
private: aC
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int m_size; S zqY@  
int m_index; BkO)hze  
}; C{"uz_Gh  

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用该迭代器可以将任意类型对象以二进制格式输出： "M`ehgCBr  
double a = 10; 0SJ7Q
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copy(bit_iterator<double>(a), bit_iterator<double> (), ostream_iterator<bool>(cout, ""));