Хороший, годный обзор новых фич C# 7
http://www.c-sharpcorner.com/article/c-sharp-7-2-new-features-with-visual-studio-2017/
http://www.c-sharpcorner.com/article/c-sharp-7-2-new-features-with-visual-studio-2017/
C-Sharpcorner
C# 7.2 New Features With Visual Studio 2017
This article explains the new features of C# 7.2. It covers ‘ref readonly’, ‘private protected’ access modifier, Digit Separator After Base Specifier (Leading Digit Separator) and Non-trailing named arguments.