Where is shared_ptr?

There are at least three places where you may find shared_ptr:

1. If your C++ implementation supports C++11 (or at least the C++11 shared_ptr), then std::shared_ptr will be defined in <memory>.

2. If your C++ implementation supports the C++ TR1 library extensions, then std::tr1::shared_ptr will likely be in <memory> (Microsoft Visual C++) or <tr1/memory> (g++’s libstdc++). Boost also provides a TR1 implementation that you can use.

3. Otherwise, you can obtain the Boost libraries and use boost::shared_ptr, which can be found in <boost/shared_ptr.hpp>.