Boost C++ Libraries

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libs/smart_ptr/test/pointer_cast_test.cpp

http://www.boost.org/LICENSE_1_0.txt)
//

#include <boost/pointer_cast.hpp>

#include <boost/shared_ptr.hpp>
#include <boost/scoped_ptr.hpp>
#include <boost/get_pointer.hpp>

#include <boost/detail/lightweight_test.hpp>

namespace
{

// Let's create these inheritance relationship:
//
//    base   base2
//      |     |
//      derived
//         |
//  derived_derived
//

class base
{
   public:
   virtual ~base(){}
   int filler [5];
};

class base2
{
public:

    virtual ~base2(){}
    int filler [5];
};

class derived
   : public base, public base2 
{
    int filler [5];
};

class derived_derived
   : public derived
{
    int filler [5];
};

// And now some simple check functions

template <class BasePtr>
bool check_dynamic_pointer_cast(const BasePtr &ptr)
{
   //Check that dynamic_pointer_cast versus dynamic_cast
   return
   //Correct cast with dynamic_pointer_cast
   boost::get_pointer(boost::dynamic_pointer_cast<derived>(ptr)) ==
      //Correct cast with dynamic_cast
      dynamic_cast<derived*>(boost::get_pointer(ptr)) 
   &&
   //Incorrect cast with dynamic_pointer_cast
   boost::get_pointer(boost::dynamic_pointer_cast<derived_derived>(ptr)) ==
      //Incorrect cast with dynamic_cast
      dynamic_cast<derived_derived*>(boost::get_pointer(ptr));
}

template <class BasePtr>
bool check_static_pointer_cast(const BasePtr &ptr)
{
   return
   //Cast base -> derived -> base2 using static_pointer_cast
   boost::get_pointer(
            boost::static_pointer_cast<base2>(
               boost::static_pointer_cast<derived>(ptr))) ==
   //Now the same with static_cast
   static_cast<base2*>(static_cast<derived*>(boost::get_pointer(ptr)));
}

template <class BasePtr>
bool check_const_pointer_cast(const BasePtr &ptr)
{
   return   
   //Unconst and const again using const_pointer_cast
   boost::get_pointer(
      boost::const_pointer_cast<const base>
         (boost::const_pointer_cast<base>(ptr))) ==
   //Now the same with const_cast
   const_cast<const base*>(const_cast<base*>(boost::get_pointer(ptr)));
}

}

int main()
{
    {
        // Try casts with shared_ptr

        boost::shared_ptr<base> ptr(new derived);

        BOOST_TEST( check_dynamic_pointer_cast( ptr ) );
        BOOST_TEST( check_static_pointer_cast( ptr ) );
        BOOST_TEST( check_const_pointer_cast( ptr ) );
    }
   
    {
        // Try casts with raw pointer

        boost::scoped_ptr<base> ptr(new derived);

        BOOST_TEST( check_dynamic_pointer_cast( ptr.get() ) );
        BOOST_TEST( check_static_pointer_cast( ptr.get() ) );
        BOOST_TEST( check_const_pointer_cast( ptr.get() ) );
    }
    
    return boost::report_errors();
}