【c++】簡單類比實現boost庫下的shared-ptr

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//簡單類比實現boost庫下的shared_ptr   #include <iostream>#include <string.h>using namespace std;class shared_ptr_Rep{friend class shared_ptr;public:shared_ptr_Rep(const char *str = " ") :count(0){px = new char[strlen(str) + 1];strcpy(px, str);}~shared_ptr_Rep(){delete[]px;}public:void increment(){count++;}void decrement(){if (--count == 0){delete this;// 哪一個rep的count為0了釋放當時的rep  }}char* get(){return px;}private:char *px;int count;};//////////////////////////////////////////////////////////////////////class shared_ptr{public:shared_ptr(const char *str = " ") :rep(new shared_ptr_Rep(str)){rep->increment();}shared_ptr(const shared_ptr &s) :rep(s.rep){rep->increment();}shared_ptr& operator=(const shared_ptr &s){if (this != &s){rep->decrement();    // 迭代器  rep = s.rep;rep->increment();}return *this;}~shared_ptr(){rep->decrement();}public:char& operator*(){return *(rep->px);}char* operator->(){return rep->px;}private:shared_ptr_Rep *rep;  };int main(){char *p = new char('a');char *q = new char('b');shared_ptr s1(p);cout << *s1 << endl;shared_ptr s2 = s1;cout << *s2 << endl;shared_ptr s3(q);s3 = s2;cout << *s3 << endl;shared_ptr s4(q);cout << *s4 << endl;shared_ptr s5 = s4;cout << *s5 << endl;return 0;}

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【c++】簡單類比實現boost庫下的shared-ptr