Is there a signal/slot library for embedded that is similar to Qt Signals & Slots?

Question

Programming

Is there a handy signal and slot library that works together seamlessly in RTOS (like FreeRTOS)?
STM32 level microcontroller. So that you can connect signals and slots from different threads.
I saw several signal/slot implementations. Somewhere more, somewhere less template magic, macros.
But I haven't seen code generation like Qt has.
The code generation idea seems to me to be more productive. You can achieve a more beautiful syntax.
In general, I'm looking for "Qt for the smallest".
UPD:
If I'm going to deal with this issue, I'll start with this project woboq.com/blog/moc-with-clang.html
Its author repeated the MOC functionality using Clang.

Answer 1

signal/slot from Qt is a normal "observer" poster.
What is stopping you from implementing your own version for your own purposes?

Answer 2

Look towards Clang. He can

Answer 3

Qt first processes the source code, replacing signals and slots in constructs understood by the C++ compiler, and only then compiles. As a result - user-friendliness and violation of the C ++ standard. You can try to write your own precompiler for the same needs.