Version 4.0 of the .NET Framework included a new CLR which is almost entirely backwards compatible with the 2.0 version of the CLR. However, by default, mixed-mode assemblies targeting .NET 3.5sp1 and earlier will fail to load in a .NET 4 application. Fixing this requires setting useLegacyV2RuntimeActivationPolicy in your app.Config for the application. While there are many good reasons for this decision, there are times when this is extremely frustrating, especially when writing a library. As such, there are (rare) times when it would be beneficial to set this in code, at runtime, as well as verify that it’s running correctly prior to receiving a FileLoadException.
Donald Knuth is a fairly amazing guy. I consider him one of the most influential contributors to computer science of all time. Unfortunately, most of the time I hear his name, I cringe. This is because it’s typically somebody quoting a small portion of one of his famous statements on optimization: “premature optimization is the root of all evil.”
I mention that this is only a portion of the entire quote, and, as such, I feel that Knuth is being quoted out of context. Optimization is important. It is a critical part of every software development effort, and should never be ignored. A developer who ignores optimization is not a professional. Every developer should understand optimization – know what to optimize, when to optimize it, and how to think about code in a way that is intelligent and productive from day one. Read more