with "setter"

[TonyValenti]

It would be great if I could use with to set multiple properties on an existing object, similar to what I can do with object initializer syntax.

Here's an a example of what I'd like to do:

var P = new Person();
...

with P {
   First_Name = "John",
   Age = 21,
   Children = {
     new(){ First_Name = "James" },
   }
};

[333fred]

Duplicate of #1534.