is(this : myClass)

[Patrick]

On Friday, 20 October 2017 at 23:01:25 UTC, Steven Schveighoffer 
wrote:
> On 10/20/17 6:23 PM, Patrick wrote:
>> On Friday, 20 October 2017 at 22:15:36 UTC, Steven 
>> Schveighoffer wrote:
>>> On 10/20/17 5:55 PM, Patrick wrote:
>>>> Due to the very specific nature of the 'is' operator, why 
>>>> wouldn't the compiler know to implicitly query the class 
>>>> types? Why must it be explicitly written, typeof(this)?
>>>
>>> The compiler generally doesn't "fix" errors for you, it tells 
>>> you there is a problem, and then you have to fix it. You have 
>>> to be clear and unambiguous to the compiler. Otherwise 
>>> debugging would be hell.
>>>
>> Not asking the compiler to fix my errors.
>> 
>> When would
>> is(this, myClass) not mean: is(typeof(this) : typeof(myClass))?
>
> class C
> {
> }
>
> int c;
>
> C myC;
>
> is(myC : c);
>
> oops, forgot to capitalize. But compiler says "I know, you 
> really meant is(typeof(myC) : typeof(c)) -> false.
>
> -Steve

If I explicitly wrote: is(typeof(myC) : typeof(c)) the outcome 
would still be false and it would still require debugging. So 
your example demonstrates nothing other then a type-o was made. 
Try again...

In this unique case, the compiler should identify the class and 
primitive types are incompatible and should issue an error 
instead (and not return false).

Patrick