Have you ever seen these mysterious ‘in’ and ‘out’ keywords in generic interfaces’ definitions? If so, you’ve probably already checked what it means, but if not… You better read this and the next post. So today we will talk about the basics of variance in our own generic interfaces.

It’s pretty funny to me when you think that you know some programming language quite well and suddenly you find out some feature, you’ve never heard before. I mean at all. That’s exactly what happened to me yesterday. Let’s see what’s that. Generics are very useful in programming since we can avoid writing similar code multiple times. But when we start to complicate them too much, it quickly reduces the legibility of the code. Of course, I don’t claim that whe...

I've seen many posts about generics in C# lately. And while they cover basics pretty well, most of them doesn't contain information about constraints which are things that causing generics to be really fun.

A więc zaczynamy przygodę z LINQ! Na pierwszy ogień biorę ‘generyczność’ czy ‘generics’ jak kto woli. Wspaniały, cudowny, dodaj swoje fjuczer, który zostal wprowadzony wraz z C# 2 i .NET 2.0.  Dlaczego na pierwszy ogień? Bo według mnie to najważniejsza rzecz wprowadzona w tamtych czasach. Zapewne niewielu czytających pamięta czasy sprzed kolekcji generycznych. Śpieszę z przypomnieniem.

I would like this blog post to serve as a quick reference that recalls the basic concept of covariant and contravariant type parameters of generic interfaces in the C# language.I tried to keep the example as simple as possible. Included comments explain the key points. No long stories and no dissertations.