Late Initializers

[RandyBuchholz]

One of the things I miss when working with Tasks and DI is simple initialization.

var foo = new Bar() {
   a : "One",
   b : 2
}

It would be nice to be able to do this with injected things

var foo = _factory.GetNewBar() {
   a : "One",
   b : 2
}

or Task results

var foo = async GetNewBar() {
   a : "One",
   b : 2
}

[DavidArno]

I'm not opposing this idea, but isn't it just introducing a with statement to C#? It (probably) could just let me do:

var foo = new Bar();
foo {
   a : "One",
   b : 2
}

I'm sure I read recently that there are problems with with in VB.Net, but I may be imagining this.

[RandyBuchholz]

@DavidArno I think a difference is one line vs multiple lines, and expression body everything idea.

public Bar Bar { get => _factory.GetNewBar() { a : "One", b : 2 }; }

or did you mean something like

var foo = new Bar() with
foo {
   a : "One",
   b : 2
};

[DavidArno]

No, I didn't mean that, so I guess my code isn't clear. With what you propose, I could do:

var foo = new Bar();
// some code
var bar = foo {
   a : "One",
   b : 2
}

But foo already have a reference to that instance of Bar, so I don't need a second one. I could there do:

var foo = new Bar();
// some code
_ = foo {
   a : "One",
   b : 2
}
// foo.a is now "One", foo.b is 2

But why have that _ =? Lose that and it becomes:

var foo = new Bar();
// some code
foo {
   a : "One",
   b : 2
}

At this point we have a with-like feature. So maybe just expand it to allow method invocations too:

var foo = new Bar();
// some code
foo {
   a : "One",
   b : 2,
   SomeMethod()
}

And now it's a complete with statement...