1.1 shared_ptr 参考:https://zh.cppreference.com/w/cpp/memory/shared_ptr std::shared_ptr是通过指针保持对象共享所有权的智能指针。多个shared_ptr对象可占有同一对象。下列情况之一出现时销毁对象并解分配其内存: 最后剩下的占有对象的shared_ptr被销毁; 最后剩下的占有对象的shared_ptr被通过operator=或reset(...
shared_ptr<int> sp(newint(10));//一个指向整数的shared_ptrassert(sp.unique());//现在shared_ptr是指针的唯一持有者shared_ptr<int> sp2 = sp;//第二个shared_ptr,拷贝构造函数assert(sp == sp2 && sp.use_count() ==2);//两个shared_ptr相等,指向同一个对象,引用计数为2*sp2 =100;//使用...
std::shared_ptr<A> ptr_a = std::make_shared<A>(); std::shared_ptr<B> ptr_b = std::make_shared<B>(); shadow_a = ptr_a; shadow_b = ptr_b; ptr_a->pb = ptr_b; ptr_b->pa = ptr_a; cout <<"reference count of A = "<< shadow_a.use_count() << endl; cout <<"...
usingVec =std::vector<int>;std::shared_ptr<int> GetSPtr() {autoelts = {0,1,2,3,4};std::shared_ptr<Vec> pvec =std::make_shared<Vec>(elts);returnstd::shared_ptr<int>(pvec, &(*pvec)[2]);}std::shared_ptr<int> sptr = GetSPtr();for(inti =-2; i <3; ++i) {printf(...
C.151: Use make_shared() to construct objects owned by shared_ptrs C.151:使用make_shared构建shared_ptr管理的对象 Reason(原因) make_shared gives a more concise statement of the construction. It also gives an opportunity to eliminate a separate allocation for the reference counts, by placing th...
weak_ptr可以解决这个问题,只会指向对象,对象的计数不会加1。 参考链接: http://www.cplusplus.com/reference/memory/shared_ptr/ 分类: C/C++ 标签: 内存泄漏 , 引用计数 , 循环引用 , 所有权 , 智能指针 , unique_ptr , shared_ptr , auto_ptr , weak_ptr 好文要顶 关注我 收藏该文 微信分享 ...
Provide valuesemantics, but use efficient reference-counting underneath to avoid copies. */ template<typename T, typename Stack> class ConstStack { struct Entry { Entry(std::shared_ptr<Entry const> parent, T value) : Value(std::move(value)) ...
所有权(ownership,auto_ptr/unique_ptr) 引用次数(reference counting,shared_ptr) explicit(显示)构造函数,指针作为参数 explicit auto_ptr(deprecated in C++11) 行为不确定 no new[]/delete[] #include<memory>auto_ptr<int>a(newint(1));auto_ptr<int>b;b=a;// a loses ownership ...
cppreference.com 3、第一个C++程序 C++兼容C语言 代码语言:javascript 复制 intmain(){printf("Hello World!\n");return0;} C++兼容C语言绝大多数的语法,所以C语言实现的hello world依旧可以运行,C++中需要把定义文件代码后缀改为.cpp,VS编译器看到是.cpp就会调用C++编译器编译,Linux下要用g++编译,不再是gcc...
// a new reference on bufCtx is returned, it does not get destoyed } void do_something(size_t init_body_len) { smart struct BufferBody *ctx = write_buffer("hello smart ptr.", init_body_len); printf("%s \n", ctx->buffer); ...