Built-In ?=-Operator in C#

[therealhappy]

A built-in operator like '?=' to assign a value to variable, if the current value is null.

The expected behavior

Instead of writing

    List<short> listOfNumbers = null;
    [...]
    if (listOfNumbers == null)
    {
        listOfNumbers = new List<short>();
    }

Simply write this

    List<short> listOfNumbers = null;
    [...]
    listOfNumbers ?= new List<short>();

[dsaf]

#10556, #10249, #9529, #8894, #5163, #3366, #205

[HaloFour]

listOfNumbers = listOfNumbers ?? new List<short>();