Static analysis of functors’ mathematical properties in C++ source code

The C++ Standard Template Library (STL) is the most well-known and widely used library that is based on the generic programming paradigm. STL takes advantage of C++ templates, so it is an extensible, effective and flexible system. Professional C++ programs cannot miss the usage of the STL because it increases quality, maintainability, understandability and efficacy of the code. However, the usage of C++ STL does not guarantee perfect, error-free code. Contrarily, incorrect application of the library may introduce new types of problems. Unfortunately, there is still a large number of properties that are tested neither at compilation- time nor at run-time. It is not surprising that in implementations of C++ programs so many STL-related bugs may occur. It is clearly seen that the compilation validation is not enough to exclude STL-related bugs. For instance, the mathematical properties of user-defined sorting parameters are not validated at compilation phase nor at run-time. Contravention of the strict weak ordering property results in weird behavior that is hard to debug. In this paper, we argue for a static analysis tool which finds erroneous implementation of functors regarding the mathematical properties. The primary goal is to support Continuous Integration pipelines, using this tool during development to overcome debugging efforts.