Qt Creator always prompts red information In included file: unknown type name 'b', how to solve it?

1. Problem description

As the title, Qt Creator always prompts red information In included file: unknown type name 'b', how to solve it?

2. Solution

In fact, these prompt information will not affect the compilation of the source code, but it looks annoying, so how to remove these information?

In the C++ option, uncheck [Use clangd]

3. Essential reasons

Because Clang Code Model is enabled by default starting from Qt Creator 4.7.0. Using ClangCodeModel to check for grammatical errors will result in the above errors. For details, please refer to the official documentation:

https://doc.qt.io/qtcreator/creator-clang-codemodel.html