Question

I want to create an extension method which I can invoke on an object .

The return value will be defined by a function.

Something like this : ( this is just an example )

bool isMature= thePerson.Age.Apply<bool>(d =>   {    if (d >18) return true;
                                                        return false;
                                                 })

and here is the extension method :

  public static Tout Apply<Tout>(this Object obj, Func< Tout> f)  
        {

            return f( );
        }

The error : incompatible anonymous function signature

What am I doing wrong ?

Answer 1

Your method takes just a Func<Tout> – which is a function taking no parameters, but returning a value.

Your lambda expression has a parameter (d) – and it looks like you’re assuming that’s an integer. It’s not clear what you’re trying to do, but if you want to use a parameter in the lambda expression, you’re going to have to change the signature from Func<TResult> to Func<TArg, TResult> or something similar – and provide an argument in the invocation.