问题转载自:https://stackoverflow.com/questions/4937180/a-base-class-pointer-can-point-to-a-derived-class-object-why-is-the-vice-versa 看到这个问题,我的想法就是这不就是包含和被包含的关系吗,所以基类指针可以指向派生类对象,但是派生类指针不可以指向派生类对象.但是这又是为什么呢?这是理论上来回答这个问题,但是实现上呢? 下面有几个网友的回答: 1 jk.举了一个例子:如果你告…

#include <iostream> struct CloneableBase { ; }; template<class Derived> struct Cloneable : CloneableBase { virtual CloneableBase* clone() const { return new Derived(static_cast<const Derived&>(*this)); } }; struct D1 : Cloneable<D…

PS: http://stackoverflow.com/questions/7934540/when-exactly-does-the-virtual-table-pointer-in-c-gets-set-for-an-object This is strictly Implementation dependent. For Most compilers, The compiler initializes this->__vptr within each constructor's Memb…

致谢 本文是基于对<Inside the c++ object model>的阅读和gdb的使用而完成的.在此感谢Lippman对cfront中对象模型的解析,这些解析帮助读者拨开迷雾.此外,Linux下无比强大的gdb工具更是驱散"黑暗"的"明灯".  :) No-Inheritance class Base { public: ; static int b; ; void showBase1(); static int showBase2(); };…

Programming language evolves always along with Compiler's evolvement The semantics of constructors One of the most often heard complaints about C++ is that the compiler does things behind the programmer’s back. We shall know how underlying compiler d…

1:多重继承 对于一个继承了多个base class 的对象,将其地址指定给最左端(也就是第一个)base class的指针, 情况将和单一继承时相同,因为两者都指向相同的其实地址.至于第二个或者更后面的base class的 地址指定操作(把derived class对象地址 赋给 第二个base class类型的指针),则需要将地址修改 加上,介于中间的base class subobject(s)大小 如果有这样的继承关系 则布局情况 2:虚拟继承 虚拟继承 一般的布局策略是先安排好der…

Access Control And Inheritance Protected Member Like private, protected members are unaccessible to users of the class Like public, protected members are accessible to members and friends of classes derived from this class. Members and friends of a d…

http://stackoverflow.com/questions/3523145/pointer-arithmetic-for-void-pointer-in-c When a pointer to a particular type (say int, char, float, ..) is incremented, its value is increased by the size of that data type. If a void pointer which points to…

There is a base class at the root of the hierarchy, from which the other class inherit, directly or indirectly. These inheriting classes are known as derived calsses. The key ideas in Object-Oriented Programming are data abstraction, inheritance and…

For Developers‎ > ‎ Smart Pointer Guidelines What are smart pointers? Smart pointers are a specific kind of "scoping object". They are like regular pointers but can automatically deallocate the object they point to when they go out of scope.…