If you are stuck with Visual Studio 2008 for some reason and need to compile C++ code that is using C++11 features like
unordered_set, then the TR1 may be an option for you. TR1 is an early draft of the features that were later incorporated into C++11. To get TR1 for Visual Studio 2008, download the Visual C++ 2008 Feature Pack Release from here.
Note that, the namespace for the TR1 features will be
std::tr1. For example,
std::unordered_set needs to be called as
std::tr1::unordered_set. A minor inconvenience, but easy to find and replace in the code.