.. title:: clang-tidy - misc-forward-declaration-namespace misc-forward-declaration-namespace ================================== Checks if an unused forward declaration is in a wrong namespace. The check inspects all unused forward declarations and checks if there is any declaration/definition with the same name existing, which could indicate that the forward declaration is in a potentially wrong namespace. .. code:: c++ namespace na { struct A; } namespace nb { struct A {}; } nb::A a; // warning : no definition found for 'A', but a definition with the same name // 'A' found in another namespace 'nb::' This check can only generate warnings, but it can't suggest a fix at this point.