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Question

I got a question about pointers:

class CAppFramework : public IBaseApp
{
public:
    CAppFramework( std::initializer_list< CClientApp* > input );
    CAppFramework( );
    ~CAppFramework( );

    void Create( ) override;
    void Release( ) override;

    template< class T > T** Request( std::string c_appname )
    {
        for ( auto c_app : m_ClientApps )
        {
            if ( c_app -> GetName( ) == c_appname )
            {
                T** t_app = reinterpret_cast< T** >( c_app );

                return t_app;
            }
       }

       return nullptr;
   }

   std::vector< CClientApp* >& GetClientApps( );

private:
   std::vector< CClientApp* > m_ClientApps;
};


void CTest::Create( )
{
    std::cout << "Ayye" << std::endl;

    CTest* test = *( m_Framework->Request< CTest >( 
    "Test" ) );
    test -> RunTest( );
}

CTest is a derived class from CClientApp.

Do I need to delete test? Cause if I do, I get an access violation. I suppose that is because "Request" is returning a pointer to a pointer that is inside a vector, so when I dereference it and delete it, it would delete the object in the vector which will / might still get used?

This is more of a general question. Do I need to delete every pointer or just pointers that are dynamically allocated using "new"?

I hope someone can help me.

Answer 1

You obviously don't need to delete every pointer, otherwise you would have to write code like this:

 int main( int argc, char ** argv ) {
      // stuff
      delete argv;
 }

If you explicitly create something with new and assign the pointer new gives you to a raw pointer, then you need to delete that pointer. Of course, this is error prone, and can't be made exception-safe, and so you should be using things like std::unique_ptr and std::make_unique instead.