Why don't tuples work?

Question

C++ / C#

I'm working in a brand new Visual Studio 2017.
C# 7 code with tuples doesn't compile.

How to fix it?

Answer 1

Add using System.ValueTuple. The pop-up message tells you directly. Links should include this item:

Answer 2

update/download the .Net Framework
in VS2015 at the exit (and still) there were/are different bugs. And in VS2017 with a probability of 99.9% they are also there.