I'm investigating CLion EAP release 138.1965.
I suggest there is a bug or possible feature in Implement Methods... I have header file test.h with Test class definition. My test class has constructor declaration only. Then I'm using Implement Methods tool, and there is obviously only constructor in suggested methods to implement list. I'm pressing OK, and IDE generates every time an boilerplate implementation for my constructor despite of there is an implemetation already. Here is couple of sceenshots illustrating that issue.