Doesn't C# Extension Methods allow passing parameters by reference?

Question

Is it really impossible to create an extension method in C# where the instance is passed as a reference?

Here’s a sample VB.NET console app:

Imports          


        

Answer 1

Yikes - you're making a mutable immutable struct. It breaks what people expect to see in C#, but if you must, then you can always directly call the method:

Ext.Add(ref value, arg1);

Any extension method is directly callable.

Also, a clarification:

SomeReferenceType value = ...;
SomeReferenceType copy = value;
value.ExtensionMethodByRef(...);
// this failing is semantically ridiculous for reference types, which
// is why it makes no sense to pass a `this` parameter by ref.
object.ReferenceEquals(value, copy);