C++ Templates: Separating declaration from implementation

I found out the hard way that it isn't as easy to separate declaration and implementation of template classes (via .h and .cpp files) as it is for regular classes. In fact, it's not even possible to do so. The following questions and answers on StackOverflow shed some light on why this limitation exists:

• Why can templates only be implemented in the header file?
• Why should the implementation and the declaration of a template class be in the same header file?
• Splitting templated C++ classes into .hpp/.cpp files--is it possible?