I created a template class EWMA in my project, but when using the class in my main.cpp, I get an undefined reference to EWMA<int, 2>::EWMA(float) Error. The .h and .cpp files of this class are inside lib/EWMA/. The .h file looks as following: #ifndef _EWMA_H #define _EWMA_H #include <Filter.h> temp…

[image] colmear: The .cpp file [image] colmear: template<typename T, int dimensions> EWMA<T, dimensions>::EWMA(float alpha[dimensions]) { this->alpha = alpha; } You cannot implement templates in cpp files that way. See Standard C++ . Not a PlatformIO error, purely C++ error.