How to invert a System.Predicate<T>

Let's say I have a Predicate<T>, and I want to call method foo with said predicate returning true, and I want to call method bar with a predicate returning false, how can I do this:

Predicate<int> p = i => i > 0
foo(p);
bar(!p); // obviously this doesn't work

If the predicate was a Func<int, bool> f, I could just !f(i)

You can easily create a method to return an "inverted" predicate - you could even make it an extension method:

public static Predicate<T> Invert<T>(this Predicate<T> predicate)
{
    // TODO: Nullity checking
    return x => !predicate(x);
}

Then:

bar(p.Invert());

Basically it's exactly what you'd do if you had a Func<int, bool> - there's nothing "magic" about either of those delegate types.

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