Emulating C++0x concepts

A library for the emulation of C++0x concepts developed using the emerging C++11 programming language is presented. The library integrates existing techniques for concept checking and template metaprogramming to provide a uniform interface to defining and using concepts. The purpose of this work is to establishing a concrete foundation for experimentation of design techniques for concepts and to motivate and evaluate language design. The viability of the approach is demonstrated by applying it to characterize a number of previously identified usability problems with concepts in the proposed C++0x language. In particular, issues related to the use of explicit and automatic concepts in generic library design from the perspective of this experiment are examined. Issues related to concept refinement, default implementations of requirements, and the generation of error messages are also discussed.