Unable to use ReactiveArduinoLib in two cpp files because of emitting code. Linker errors.

[rzeldent]

When there are two cpp files present that include the ReactiveArduinoLib.h file, linking breaks.
This is probably caused because not all the definitions are templates but do generate code.
Looks like this is caused by the Serial Observables.
Project to reproduce in PlatformIO is attached.

Archive.zip

Linking .pio/build/esp32dev/firmware.elf
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<unsigned char>::Suscribe(IObserver<unsigned char>&)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialByte.h:30: multiple definition of ObservableSerial::Suscribe(IObserver&)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialByte.h:30: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<char>::Suscribe(IObserver<char>&)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialChar.h:30: multiple definition of ObservableSerial::Suscribe(IObserver&)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialChar.h:30: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<String>::Suscribe(IObserver<String>&)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialString.h:33: multiple definition of ObservableSerial::Suscribe(IObserver&)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialString.h:33: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<int>::Suscribe(IObserver<int>&)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialInteger.h:35: multiple definition of ObservableSerial::Suscribe(IObserver&)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialInteger.h:35: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<float>::Suscribe(IObserver<float>&)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialFloat.h:42: multiple definition of ObservableSerial::Suscribe(IObserver&)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialFloat.h:42: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<double>::Suscribe(IObserver<double>&)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialDouble.h:42: multiple definition of ObservableSerial::Suscribe(IObserver&)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialDouble.h:42: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<unsigned char>::ObservableSerial()': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialByte.h:25: multiple definition of ObservableSerial::ObservableSerial()'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialByte.h:25: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<unsigned char>::ObservableSerial()': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialByte.h:25: multiple definition of ObservableSerial::ObservableSerial()'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialByte.h:25: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<char>::ObservableSerial()': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialChar.h:25: multiple definition of ObservableSerial::ObservableSerial()'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialChar.h:25: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<char>::ObservableSerial()': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialChar.h:25: multiple definition of ObservableSerial::ObservableSerial()'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialChar.h:25: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<String>::ObservableSerial(char)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialString.h:27: multiple definition of ObservableSerial::ObservableSerial(char)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialString.h:27: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<String>::ObservableSerial(char)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialString.h:27: multiple definition of ObservableSerial::ObservableSerial(char)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialString.h:27: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<int>::ObservableSerial(char)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialInteger.h:29: multiple definition of ObservableSerial::ObservableSerial(char)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialInteger.h:29: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<int>::ObservableSerial(char)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialInteger.h:29: multiple definition of ObservableSerial::ObservableSerial(char)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialInteger.h:29: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<float>::ObservableSerial(char)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialFloat.h:36: multiple definition of ObservableSerial::ObservableSerial(char)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialFloat.h:36: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<float>::ObservableSerial(char)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialFloat.h:36: multiple definition of ObservableSerial::ObservableSerial(char)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialFloat.h:36: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<double>::ObservableSerial(char)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialDouble.h:36: multiple definition of ObservableSerial::ObservableSerial(char)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialDouble.h:36: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<double>::ObservableSerial(char)': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialDouble.h:36: multiple definition of ObservableSerial::ObservableSerial(char)'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialDouble.h:36: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<unsigned char>::Receive()': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialByte.h:35: multiple definition of ObservableSerial::Receive()'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialByte.h:35: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<char>::Receive()': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialChar.h:35: multiple definition of ObservableSerial::Receive()'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialChar.h:35: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<String>::Receive()': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialString.h:38: multiple definition of ObservableSerial::Receive()'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialString.h:38: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<int>::Receive()': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialInteger.h:40: multiple definition of ObservableSerial::Receive()'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialInteger.h:40: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<float>::Receive()': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialFloat.h:47: multiple definition of ObservableSerial::Receive()'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialFloat.h:47: first defined here
/pio/build/esp32dev/src/screen_connecting.cpp.o: in function ObservableSerial<double>::Receive()': ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialDouble.h:47: multiple definition of ObservableSerial::Receive()'; .pio/build/esp32dev/src/main.cpp.o:ibdeps/esp32dev/ReactiveArduino/src/Observables/ObservableSerialDouble.h:47: first defined here
collect2: error: ld returned 1 exit status
*** [.pio/build/esp32dev/firmware.elf] Error 1

[rzeldent]

Looks like there are some class functions in the ObserableSerial specialization classes that are missing the template<> before the implementations

[rzeldent]

Is solved by using inline so they the functions are not emitted by the header files. Saves memory if not used and possibility to include the files multiple times. See PR