Execute lambda expression immediately after its definition?

Question

Is there a way to execute a lambda expression immediately after its definition?

In other words (Invalid C# code):

Answer 1

For my own projects I've sometimes written a tiny reusable helper function to make the syntax for an immediately invoked lambda look shorter. This 'Inv' was inspired by the similar 'fun' function in the LanguageExt library.

// Helper utility functions
public static void Inv(Action a) => a();
public static T Inv(Func f) => f();

private static void TestMethod()
{
    // Action example
    Inv(() => Console.WriteLine("Hello World!"));
    // Func example with no parameters
    bool result = Inv(() =>
    {
        if (1 == 1)
            return true;
        else
            return false;
    });
}

You could also extend this with a few other overloads to make it so you could pass in parameters, but these look a bit more cumbersome syntax wise and may not be as helpful.

public static Func Inv(Func f) => f;
public static Func Inv(Func f) => f;

string printNumber = Inv((int number) => $"This is the number {number}")(5);
int addedNumbers = Inv((int x, int y) => x + y)(5, 6);