If I try to write signals/slots with trailing-return-type as described here(https://en.cppreference.com/w/cpp/language/function), that feature become available with C++11 standard decltype.

signals:
    auto testSignal() -> void;

public slots:
    auto testSlot() -> void;

But my compilation faild, as I understand moc cannot parse this signature, and gives error like that:

\AutoReturn\TestClass.hpp -o debug\moc_TestClass.cpp
..\AutoReturn\TestClass.hpp(12): Parse error at ":"

You could reproduce this issue on my small example AutoReturn.zip