https://www.lonecpluspluscoder.com/tags/object-oriented/Recent content in Object Oriented on The Lone C++ Coder's BlogHugo -- gohugo.ioenWed, 19 Nov 2014 22:24:02 +0000https://www.lonecpluspluscoder.com/2014/11/19/polymorphism-and-boost-shared_ptr/Wed, 19 Nov 2014 22:24:02 +0000Timo Geuschhttps://www.lonecpluspluscoder.com/2014/11/19/polymorphism-and-boost-shared_ptr/<p><em>Reposted from my old blog. Here&rsquo;s the news from 2009&hellip;</em></p> <p>I&rsquo;m currently in the final stages of converting a library from raw pointers to <a href="http://www.boost.org/doc/libs/1_57_0/libs/smart_ptr/shared_ptr.htm">boost::shared_ptr</a>. I&rsquo;m mainly doing this to ensure the correct pointer/pointee ownership rather than the outright prevention of memory leaks, but the latter is a nice side effect of the former.</p> <p>One problem I ran into was that the library I&rsquo;m updating and its clients make rather heavy use of polymorphism. Of course in 99% of the code that was fine as the objects were accessed through pointers to base classes, but the last 1% was causing problems because that part of the code contained lots of <code>dynamic_cast</code> statements. These classes unfortunately need to know the exact type they were dealing with so there was no easy way around the use of these idioms. It probably isn&rsquo;t news to most of the people reading this blog that dynamic_cast and boost::shared_ptr don&rsquo;t play that nicely.</p>