I discovered, from asking a question on the user NG, the Concept Traits Library ( mentioned at https://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction#Boost.Conce... ) in the Boost sandbox by Terje Slettebø and Tobias Schwinger last dated almost 6 years ago. From e-mailing Terje Slettebø I discovered that he did not have time to work on it further or submit it to Boost, since he has been working in other areas for many years as part of his job. Tobias Schwinger's e-mail address was not in the documentation so I was not able to contact him. Other Boost TMP programmers also seemed to have helped to contribute to this library. How did this library slip under the raider, so to speak ? This is a fantastic library with many useful metafunctions for the TMP programmer. For my own particular use the operator metafunctions alone are incredibly useful, but there are many more metafunctions testing for many concepts covering the STL and MPL. The documentation is also very good and there is a complete set of tests. Have I missed anything in terms of other later libraries superceding the functionality that was in this one ? Are the techniques used in this library flawed in any way ? I would love to see this library as part of Boost, if just for the operator metafunctions, and have told Terje Slettebø so.