why do I have to explicitly ask whether a nullable boolean var is true?

Question

bool? nullableVar;
if(nullableVar) 

gives me an error but

if(nullableVar==true) 

evaluates fine.

Not sure I follow on why that is given that if the bool wasn't nullable would evaluate fine?

Answer 1

The condition expression of an if has to be implicitly convertible to bool. Nullable<bool> is not convertible to bool, but the second expression is already of type bool, so it's okay. Looking at the IL, I believe the second expression is really being compiled to:

if (nullableVar.GetValueOrDefault())