What is an xtree is Visual C++?

Question

I'm learning about the various data structures and templates available in C++. While include the header for vectors, I came across a header called xtree. I can't find any documentation on this header file from Microsoft (using VS10). My question is what exactly is this header used for and what does it contain? Is it even a data structure? Is it an obsolete header? An example would be helpful.

Answer 1

AFAIK, it contains helper stuff used for implementing std::set and std::map, which have (this is the only sane way to achieve the required big-O performance characteristics and provide the required functionality) a tree structure internally. I can't guess why <vector> would need it - were you just browsing around in the folder?