SonarSource has been working all year to improve C++ support. Recently we adjusted standard-specific rules to run only on code compiled to that standard. So C++98 rules will no longer raise issues on your C++17 code, and vice versa! 

C++ analyzer helps developers to write C++17 compliant code

by Alexandre Gigleux

From the article:

C++17 standard is out for a while now and supported by the C++ analyzer running on SonarCloud. We did an effort in the past years to fix false-positives/false-negatives related to the new constructs/features of C++17. That was great but not enough to help you be more familiar with the standard and take the best out of it.
This is why we are happy to introduce a first set of rules dedicated to C++17. With these rules, we hope you will take advantage of the new features of C++17 and write more reliable and maintainable C++17 code.

C++ analysis is available free for open source projects in SonarCloud, and in commercial editions of SonarQube.