Func<T> with out parameter

c# .net linq generics func
blu picture blu · Aug 16, 2009 · Viewed 51.9k times · Source

Can I pass a method with an out parameter as a Func?

public IList<Foo> FindForBar(string bar, out int count) { }

// somewhere else
public IList<T> Find(Func<string, int, List<T>> listFunction) { }

Func needs a type so out won't compile there, and calling listFunction requires an int and won't allow an out in.

Is there a way to do this?

Answer

Mehrdad Afshari picture Mehrdad Afshari · Aug 16, 2009

ref and out are not part of the type parameter definition so you can't use the built-in Func delegate to pass ref and out arguments. Of course, you can declare your own delegate if you want:

delegate V MyDelegate<T,U,V>(T input, out U output);

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