unique_ptr 指针与其所指对象的关系:在智能指针生命周期内,可以改变智能指针所指对象,如创建智能指针时通过构造函数指定、通过 reset 方法重新指定、通过 release 方法释放所有权、通过移动语义转移所有权,unique_ptr 还可能没有对象,这种情况被称为 empty。[6] ^{[6]} [6] 。 unique_ptr的基本操作有: //
假设sp2 是一个初始化的shared_ptr。 //Initialize with copy constructor. Increments ref count.auto sp3(sp2);//Initialize via assignment. Increments ref count.auto sp4 =sp2;//Initialize with nullptr. sp7 is empty.shared_ptr<Song>sp7(nullptr);//此指针有指向类型,但是指向nullptr//Initialize with ...
no arguments -- the resulting object is an empty shared_ptr object or an empty weak_ptr object. ptr -- a pointer of type Other* to the resource to be managed. Ty must be a complete type. If the function fails (because the control block cannot be allocated) it evaluates the expression...
no arguments: The resulting object is an empty shared_ptr object or an empty weak_ptr object. ptr: A pointer of type Other* to the resource to be managed. T must be a complete type. If the function fails (because the control block can't be allocated), it evaluates the expression dele...
no arguments -- the resulting object is an emptyshared_ptrobject or an emptyweak_ptrobject. ptr -- a pointer of type Other* to the resource to be managed. Ty must be a complete type. If the function fails (because the control block cannot be allocated) it evaluates the expression delete...
no arguments -- the resulting object is an empty shared_ptr object or an empty weak_ptr object. ptr -- a pointer of type Other* to the resource to be managed. Ty must be a complete type. If the function fails it evaluates the expression delete ptr. ptr, dtor -- a pointer of type...
no arguments -- the resulting object is an empty shared_ptr object or an empty weak_ptr object. ptr -- a pointer of type Other* to the resource to be managed. Ty must be a complete type. If the function fails (because the control block cannot be allocated) it evaluates the expression...
no arguments -- the resulting object is an emptyshared_ptrobject or an emptyweak_ptrobject. ptr-- a pointer of typeOther*to the resource to be managed.Tmust be a complete type. If the function fails (because the control block cannot be allocated) it evaluates the expressiondelete ptr. ...
// Use make_shared function when possible. auto sp1 = make_shared<Song>(L"The Beatles", L"Im Happy Just to Dance With You"); // Ok, but slightly less efficient. // Note: Using new expression as constructor argument // creates no named variable for other code to access. shared_pt...
no arguments -- the resulting object is an emptyshared_ptrobject or an emptyweak_ptrobject. ptr -- a pointer of type Other* to the resource to be managed. Ty must be a complete type. If the function fails (because the control block cannot be allocated) it evaluates the expression delete...