# Extra Clang Tools 8 documentation

## clang-tidy - cppcoreguidelines-pro-type-static-cast-downcast

# cppcoreguidelines-pro-type-static-cast-downcast

This check flags all usages of `static_cast`, where a base class is casted to a derived class. In those cases, a fix-it is provided to convert the cast to a `dynamic_cast`.

Use of these casts can violate type safety and cause the program to access a variable that is actually of type `X` to be accessed as if it were of an unrelated type `Z`.

This rule is part of the “Type safety” profile of the C++ Core Guidelines, see https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#Pro-type-downcast.