Tertiary assignment on a nullable type wont compile if one case is non nullable and one is nullable

[KieranDevvs]

I'm trying to assign a value to a null-able type via a tertiary assignment where:
case true: assign non-nullable
case false: assign null

DateTime? assignee;
DateTime assignment;
var condition = false;

assignee = condition ? assignment: null;

This results in the compile error: Cannot convert DateTime to nullable.

I would assume that the compiler would translate this into something like:

DateTime? assignee;
DateTime assignment;
var condition = false;

if(condition) {
    assignee = assignment;
}else{
    assignee = null;
}

Which compiles fine.
Whats actually going on here?

[spydacarnage]

You can use:

assignee = condition ? assignment : default(DateTime?)

[ronnygunawan]

Related to #2823 #33

[KieranDevvs]

You can use:

assignee = condition ? assignment : default(DateTime?)

Seems like a bit of a hack, but I guess it works for now.

[333fred]

This would be addressed by #2823, which is currently on the table for c# 9

[gafter]

Closing as duplicate