C#, Tech

Cannot implicitly convert type ‘Abc<Derived>’ to ‘IAbc<Base>’ – Contravariance vs Covariance – part 2.

Today I will write about the way variance (<in T> and <out T>) influences type checking in C#. Yes, the fact that one type can be passed to a generic method that requires another type, depends on these 2 small keywords we write before ‘T’ (or whatever ?) in interface header. BTW this article is the continuation of my previous post that makes a dummy introduction to the variance – if you haven’t seen it, then you should :P. Not because I wrote anything important there, but because my google analytics statistics will grow. So as you can see – it’s worth it :P.

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C#, Tech

Enumerable.Empty<T>() vs new ‘IEnumerable’<T>() – what’s better?

Reading Microsoft documentation when we have all that stackoverflow questions with answers usually seems a waste of time. And as a typical, lazy programmer I admit that (much too often) I agree with that sentence ?. But today I decided to check how Enumerable.Empty<T>() works and wasn’t satisfied with the knowledge I got. I started digging a little bit deeper and wasted some of the precious beauty-sleep time  so if you want to know what’s happening when you add an element to an empty collection, let me tell you a story of today’s night.
No, not that story, you sick head! Continue Reading

C#, Tech

C# 8 features – part 1.

If you were online at least once in the previews week you probably noticed the biggest announcement from Microsoft! Yeah, everybody is talking about C# 8 planned features. And because the news is literally everywhere, I gave up and decided not to repeat what everybody already read. But that decision is no longer valid because back THEN (which means – yesterday or so) my pet project wasn’t so nasty and I wasn’t so stuck in the middle of some stupid, trivial task that seems to be unable to accomplish… So yeah, I changed my mind, I will wrote about C# 8, just to avoid touching (for at least a day 😉 ), the disaster I programmed :D. No, it’s not procrastination, not at all! ?

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C#, Tech

Imagine there’s no… NullReferenceException! (C# 8 plans)

Well, maybe not a totally ‘no’ NullReferenceException, but a whole lot less than now. Well, yeah, I had to catch your attention somehow :P. But anyway, have you heard those rumors about C# 8, how amazing it is going to be and how hard Microsoft is working on the release…? If not, you definitely should read this post! Because the promised changes sound really good and will be a must-to-know quite soon.

So today I wanted to write about one of the “louder” planned features – nullable reference types. Yes, you read it right. And yes, all the reference types we already have in C# are actually… nullable. Yeah, makes no sense, yeah, what a bullsh… No! Wait! Continue Reading

C#

C# stuff nobody told you – delegate is a class! And there is a good reason for that!

Have you ever wondered why blue screens of death happen so rarely, nowadays? Of course, we can thank Microsoft for this but the way they fixed this problem is not so obvious! According to Marino Posadas (and his book Mastering C# and .Net Framework) back in 2010, Microsoft made an analysis of this topic and they came to the conclusion that the 90% (wow!) of the blue screens were caused by drivers! So, Microsoft made manufacturers to follow the Hardware Compatibility List. That somehow solved most of the problem but what with the rest 10%? Most of them was due to the… Continue Reading