OT - Replacing strings with slices in C# - high performance improvement

[rumbu]

.NET Core 2.1 was announced, with emphasis on using Span<T> 
instead of classic String class all around the framework. For 
people not familiar with C#, Span<T> is similar to a D array 
slice.

https://blogs.msdn.microsoft.com/dotnet/2018/04/18/performance-improvements-in-net-core-2-1/