Immutable and unique in C#

[bearophile]

Walter Bright:

> Unique as a type qualifier comes with all kinds of subtle 
> problems. For one thing, unique is more of a property of an 
> expression rather than a property of the type.

Unfortunately I am not able to fully understand the paper linked 
by Sönke Ludwig in this thread, but maybe you are able to 
understand its main points.

Generally in this complex field I suggest to build on the ideas 
invented by researchers, and to not try to invent too much.

Bye,
bearophile