classSubject{public:virtual~Subject()=default;virtualvoidattach(std::shared_ptr<Observer>observer){ob...
dynamic_pointer_cast不是语言关键字,在标准库<memory>中定义,位于std命名空间中,专用于智能指针shared_ptr的转换。可以理解为智能指针领域的dynamic_cast操作符。 总结一下:它们的基本区别,就是dynamci_cast用于裸指针和引用等动态类型的转型,而dynamic_pointer_cast主要用于智能指针的转型。 例子: //注意:dynamic_po...
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}; std::shared_ptr<Father> father; std::shared_ptr<Son> son = std::dynamic_pointer_cast<Son>(father); 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
std::tr1::shared_ptr<RectData> pData;//see Item13 for info on}; 这段代码是返回一个Point对象,考虑到封装性问题,该对象是禁止修改的,但是他的问题是返回了private内容,可能在下面场合下出现问题。 classGUIObject { ... };constRectangle//returns a rectangle byboundingBox(constGUIObject& obj);//va...
不同之处在于，shared_dynamic_cast只适用于shared_ptr<>的，而dynamic_pointer_cast适用于任何类型的...
std::shared_ptr<T> static_pointer_cast( const std::shared_ptr<U>& r ) noexcept; (1) (since C++11) template< class T, class U > std::shared_ptr<T> static_pointer_cast( std::shared_ptr<U>&& r ) noexcept; (2) (since C++20) ...
struct Father { //基类Father }; struct Son:Father { //基类Father的派生类B }; std::shared_ptr<Father> father; std::shared_ptr<Son> son = std::dynamic_pointer_cast<Son>(father);戳戳小手帮忙点个免费的赞和关注吧,嘿嘿。文章标签: C++ 关键词: C++ dynamic_cast C++强制类型转换 C++强制...
//p.h class P{ }; //s.h #include "p.h" class S : public P{ }; //main.cpp #include <iostream> #include "s.h" int main(){ //std::shared_ptr<P> x(new S); //std::shared_ptr<S> y = std::dynamic_pointer_cast<S>(x); P* x = new S; S* y = dynamic_cast<S*...
// std_tr1__memory__dynamic_pointer_cast.cpp // compile with: /EHsc #include <memory> #include <iostream> struct base { virtual ~base() { } int val; }; struct derived : public base { }; int main() { std::shared_ptr sp0(new derived); std::shared_ptr<derived> sp1 = std::dy...