When is a unary operator not a unary operator?

[jskeet]

#1195 claims that the null-forgiving operator is not a unary operator.

I would like that to not be so, given that it's a (postfix) operator with a single operand, which has always been my understanding of "unary operator".

This may prove to be more controversial than I'd expected.

Note that unary_expression and primary_expression are not up for being changed here - even though unary_expression doesn't include all expressions using unary operators.

This bug is for research around how feasible it is to make this consistent without being too disruptive.

Note that await already counts as a "unary operator" but can't be overloaded, so "unary operator" doesn't actually mean "overloadable operator with one operand".