It would be useful to have a possibility to add bolierplate implementations for all class methods which are not yet implemented, instead of applying refactoring to each method one by one.

Probably it should have same options as existing "Add Definition" for single methods: in <filename>, inside class, outside class. I think "in <filename>" (with <filneame> being .cpp file) will be used in most cases, however "outside class" would be useful for templates.