Runtime: Add ForEach() extension method for IEnumerable

[vsfeedback]

_This issue has been moved from a ticket on Developer Community._

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ForEach is an useful method for all sorts of collections but strangely is only present as a direct method of List<T> when it would be useful in all sorts of collections or IEnumerable types. I noticed this when trying to find the method on ObservableCollection<T> (and found it was missing).

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Original Comments

Feedback Bot on 4/14/2020, 11:58 PM:

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[ygra]

I'm not sure much has changed since Eric Lippert's (IMHO) rather convincing explanation.

[eiriktsarpalis]

The foreach keyword provides a much better way to achieve the same effect. I'd be inclined to close this cc @adamsitnik

[pinkfloydx33]

My biggest pet peeve is seeing code that does the following:

IEnumerable<T> enumerable = GetSomeEnumerable();
enumerable.ToList().ForEach(c => { /* do something */ });

I think this is one of the worst antipatterns I come across regularly. There's at best a single array allocation (though likely more), plus the delegate, closure, two method calls, the enumerators and the list itself.

At my previous job I wrote an analyzer that designated this pattern as a compiler error. Adding an extension method on IEnumerable smells of the same thing. Please don't do this, let people use foreach.

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[eiriktsarpalis]

Closing since the prefered approach is to use the foreach keyword.