Clang matchers for verified usage of the C++ Standard Template Library. The C++ Standard Template Library (STL) is the exemplar of generic libraries. Professional C++ programs cannot miss the usage of this standard library because it increases quality, maintainability, understandability and efficacy of the code. However, the usage of C++ STL does not guarantee error-free code. Contrarily, incorrect application of the library may introduce new types of problems. Unfortunately, there is still a large number of properties which are tested neither at compilation-time nor at run-time. It is not surprising that in implementation of C++ programs so many STL-related bugs are occurred.par We match patterns on abstract syntax trees (AST) with the help of predicates. The predicates can be combined and define an embedded language. We have developed a tool which finds the potential missuses of the STL as a validation of our approach. The software takes advantage of the Clang AST Matcher technology. The tool is in-use in Ericsson. We advise new matchers that have get into the Clang code base.