Issue: var does not handle Generic anonymous functions

[pmunin]

Expected Behavior:

var selector = (Node n) => {
     return new {Node = n, ChildrenCount = n.Children.Count };
}

Actual Behavior:

public static class Workaround
{
    public static Func<T1,TResult> Function<T1,TResult>(Func<T1,TResult> func)
    {
        return func;
    }
}

///...

var selector = Workaround.Function( (Node n) => {
     return new {Node = n, ChildrenCount = n.Children.Count };
});

[HaloFour]

Dupe of #14 which was already closed.

In short, delegates are all different types according to the CLR and they are incompatible with each other even if their signature matches. The C# language has no special knowledge of any specific delegate types, including the Func<...> or Action<...> delegate families. If lambda inference were to decide to use Func<...>, assuming that could be done unambiguously, assigning that to a variable or parameter of a different-but-compatible signature would involve wrapping the delegate with another delegate. That doubles the overhead when invoking the delegate, each call costing about the same as a virtual instance method call, which isn't a lot but can add up in aggregate.

[aluanhaddad]

I still think this is worth reconsidering, especially if collection literals are on the table, because they will also have to somewhat arbitrarily target clandestine types that are conventionally used.

If lambda inference were to decide to use Func<...>, assuming that could be done unambiguously, assigning that to a variable or parameter of a different-but-compatible signature would involve wrapping the delegate with another delegate.

But isn't the suggestion here to only use Func<....> when it would otherwise be an error?

[CyrusNajmabadi]

Closing out. This is legal now in the language.