# Extra Clang Tools 4 documentation

## clang-tidy - cppcoreguidelines-pro-type-const-cast

# cppcoreguidelines-pro-type-const-cast

This check flags all uses of `const_cast` in C++ code.

Modifying a variable that was declared const is undefined behavior, even with `const_cast`.

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-constcast.