Warns when using Qt emit keyword.
This check is disabled by default and must be explicitly enabled.
Note that C++20 has a method named emit(), therefore it's advisable to switch to using the Q_EMIT macro to prevent name conflicts (perferably before starting to use Qt code with C++20). See https://cplusplus.github.io/LWG/issue3399 if you're interested in the details.
This check is mainly useful due to its fixit to automatically convert the emit keyword to its Q_ variant. Once you've converted all usages, then simply guard against emit being reintroduced in your codebase with ADD_DEFINITIONS(-DQT_NO_EMIT) (CMake) or CONFIG += no_keywords (qmake).
This check is a "subset" of the qt-keywords check, which warns about emit and other Qt keywords.