This paper explains a tool-based approach to detect source-code patterns that can be substituted with calls to the C++ standard template library (STL). The goal of the tool is to support developers in the process of refactoring a legacy code base to make use of modern library interfaces and standardized algorithms. This way, the intention of the programmer is encoded more explicitly in the code to increase readability. In addition, the STL is well tested, i.e., its use can improve robustness. We show early results from applying our tool to the High-Performance Conjugate Gradient (HPCG) benchmark. The current prototype creates roughly 50% false positives, all of which a human can easily identify.