title: Does C# 7.0 work for .NET 4.5?
body: <p>I created a project in Visual Studio 2017 RC to check whether I can use new C# 7.0 language features in a .NET Framework 4.5 project. It seems to me that after referencing <code>System.ValueTuple</code> NuGet, new tuples are working fine. Is there anything else I should think about, or is this going to work?</p>
  
  <p>After checking <code>System.ValueTuple</code> NuGet dependencies, it looks like .NET Framework 4.0 is not supported. Is this the case, or is there some way to make the new language work in this runtime also?</p>