Axiom-Based Transformations: Optimisation and Testing

Programmers typically have knowledge about properties of their programs that aren't explicitly expressed in the code – properties that may be very useful for, e.g., compiler optimisation and automated testing. Although such information is sometimes written down in a formal or informal specification, it is generally not accessible to compilers and other tools. However, using the idea of concepts and axioms in the upcoming C++ standard, we may embed axioms with program code. In this paper, we sketch how such axioms can be interpreted as rewrite rules and test oracles. Rewrite rules together with user-defined transformation strategies allow us to implement program or library-specific optimisations.