Is there idiomatic C# equivalent to C's comma operator?

Question

I'm using some functional stuff in C# and keep getting stuck on the fact that List.Add doesn't return the updated list.

In general, I'd like to call a function on an object and then return the updated object.

For example it would be great if C# had a comma operator:

((accum, data) => accum.Add(data), accum) 

I could write my own "comma operator" like this:

static T comma(Action a, Func<T> result) {     a();     return result(); } 

It looks like it would work but the call site would ugly. My first example would be something like:

((accum, data) => comma(accum.Add(data), ()=>accum)) 

Enough examples! What's the cleanest way to do this without another developer coming along later and wrinkling his or her nose at the code smell?

Answer 1

I know this as Fluent.

A Fluent example of a List.Add using Extension Methods

static List<T> MyAdd<T>(this List<T> list, T element) {     list.Add(element);     return list; } 

Answer 2

I know that this thread is very old, but I want to append the following information for future users:

There isn't currently such an operator. During the C# 6 development cycle a semicolon operator was added, as:

int square = (int x = int.Parse(Console.ReadLine()); Console.WriteLine(x - 2); x * x); 

which can be translated as follows:

int square = compiler_generated_Function();  [MethodImpl(MethodImplOptions.AggressiveInlining)] private int compiler_generated_Function() {     int x = int.Parse(Console.ReadLine());      Console.WriteLine(x - 2);      return x * x; } 

However, this feature was dropped before the final C# release.