Chapter 44. Casts

Difficulty: 6

How well do you know C++'s casts? Using them well can greatly improve the reliability of your code.

The new-style casts in standard C++ offer more power and safety than the old-style (C-style) casts. How well do you know them? The rest of this problem uses the following classes and global variables:

class  A { public: virtual ~A(); /*...*/ }; 
A::~A() { }

class B : private virtual A  { /*...*/ };

class C : public  A          { /*...*/ };

class D : public B, public C { /*...*/ };

A a1; B b1; C c1; D d1;
const A  a2;
const A& ra1 = a1;
const A& ra2 = a2;
char c;

This Item presents four questions.

  1. Which of the following new-style casts are not equivalent to a C-style cast?

    const_cast 
    dynamic_cast
    reinterpret_cast
    static_cast
    
  2. For each ...

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