The Old New Thing

Why can't I declare a type that derives from a generic type parameter?

August 14, 2009 Aug 14, 2009 08/14/09
Raymond Chen
A lot of questions about C# generics come from the starting point that they are just a cutesy C# name for C++ templates. But while the two may look similar in the source code, they are actually quite different. C++ templates are macros on steroids. No code gets generated when a template is "compiled"; the compiler merely hangs onto the ...

Landing the Space Shuttle is hard enough as it is

August 13, 2009 Aug 13, 2009 08/13/09
Raymond Chen
I was at The Museum of Flight and was waiting my turn at the Space Shuttle landing simulator. A six-year-old settled into the control seat, and as the simulation began I heard him ask his father, "Where are the bad guys?" I'm pretty sure the Space Shuttle doesn't come with onboard missiles. That didn't stop the kid from pressing the ...

Common gotchas when writing your own p/invoke

August 13, 2009 Aug 13, 2009 08/13/09
Raymond Chen
If you're looking to get into some p/invoke action, you'd be well-served to check out the pinvoke wiki to see if somebody else has done it too. If what you need isn't there, you may end up forced to write your own, and here are some gotchas I've seen people run into: C++ and Win32 are not the same as C# (aka ). In Win32...

The wisdom of sev^H^H^Heighth graders: What it means to be an adult

August 12, 2009 Aug 12, 2009 08/12/09
Raymond Chen
Since I'm obviously a glutton for punishment, I also helped read eighth grade essays on the same topic: Describe the qualities you consider to be those which make someone an adult. As always, remember that these are just the funny sentences/excerpts. Let me tell you about my parents Entering a no fun zone It's harder than I thought ...

Why can't I pass a reference to a derived class to a function that takes a reference to a base class by reference?

August 12, 2009 Aug 12, 2009 08/12/09
Raymond Chen
"Why can't I pass a reference to a derived class to a function that takes a reference to a base class by reference?" That's a confusing question, but it's phrased that way because the simpler phrasing is wrong! Ths misleading simplified phrasing of the question is "Why can't I pass a reference to a derived class to a function that takes a ...

The wisdom of seventh graders: What it means to be an adult

August 11, 2009 Aug 11, 2009 08/11/09
Raymond Chen
I didn't participate in the reading of the seventh grade essays, but I did get some of the more entertaining sentences from that batch. As you may recall, the topic was to describe the qualities you consider to be those which make someone an adult. Students were given 90 minutes, plus one additional hour upon request, equipped only with paper ...

Actually, FlagsAttribute can't do more; that's why it's an attribute

August 11, 2009 Aug 11, 2009 08/11/09
Raymond Chen
A few years ago, Abhinaba wondered why FlagsAttribute didn't also alter the way enumeration values are auto-assigned. Because attributes don't change the language. They are instructions to the runtime environment or (in rarer cases) to the compiler. An attribute can instruct the runtime environment to treat the function or class in a ...

The wisdom of seve^H^H^H^Hsixth graders: What it means to be an adult

August 10, 2009 Aug 10, 2009 08/10/09
Raymond Chen
I was out of town for the grading of the seventh grade essays, so I pitched in with the sixth grade essays instead. The students were asked to think of an adult and describe the qualities that make that person an adult. This topic was not very well received by the students, who deemed it uncreative and boring. While I understand their lack of ...

Not beany enough

August 7, 2009 Aug 7, 2009 08/7/09
Raymond Chen
The other night, I was playing a friendly game of Scrabble®, and I managed to play BEANIER* (meaning "with a stronger flavor of beans") onto a triple-word score, crossing the B with an open Y, scoring over 100 points in the process. This sufficiently demoralized the other players that the game turned into "play anything that ...