Is there a simple way to check if value is null for every case?

[SG]

On Monday, 27 August 2018 at 03:21:04 UTC, rikki cattermole wrote:
> Templates make it the easiest way, since common patterns, like 
> arrays, classes and pointers have the exact same null check 
> syntax.

I see.

> That code is only for classes. C# also has structs which are a 
> value type. Which it would not work for.

The same thing for struct in C#

Struct S{
    public int? i;
}

S.i == null; // This works nicely.

> You don't need isNull function for Nullable because it has a 
> method called it. That will be preferred (hence I specifically 
> used isNull as the name).
>
> For Variant, use hasValue.
>
> bool isNull(Variant value) {
> 	return !value.hasValue;
> }

The problem I'm trying to solve is beyond that. This is just an 
example. But bear with me, right now all I want is a function to 
check the value from 'a' type and return if it is null.

The type could be a: Class, Struct, a Basic data type, Variant, 
Nullable and so.

And what I see, these types has different behaviors, while in C# 
at least for this same case, I would write the same thing in few 
lines to perform it, in D I found very hard.

Isn't counter intuitive the way D works? Because for each type 
Class/Nullable you check with .isNull, for Variant with 
.hasValue, for string (variable is null).

Thanks.