Transition to C++17 as the minimum standard

I propose that on 2022-07-04T04:00:00Z Slicer transition to set the minimum C++ standard to C++17. See the following pull request for previous discussion and what will be integrated to complete this change.

Visual Studio 2017 (15.7) was announced to officially conform with the C++ standard of C++11, C++14 and C++17


Reminder to developers that this will happen in a week. You can like the original post to serve as your acknowledgment.

A approval to my PR is needed from another developer to be able to execute on the original proposed timeline.

To follow up, the corresponding PR has been merged.