Nicolás Brailovsky

Long time without updates. I guess I needed vacations from the blog. It was not the first time and it probably won’t be the last one I take, but I’m back now with another truckload of C++ ramblings and misc stuff. Like this one:

Even though I have vim a Vim fan for a long time there still is a lot of stuff which amazes me about this little editor,  and this thing I last learned about it is in the “ZOMG that’s so cool I’m about to pee my pants” category. Unfortunately, if I were to draw a Venn diagram of the people who may find it cool I’d have to intersect the group of people reading my blog (yes, very small) with the group of people who like Vim and Monty Python. So, here’s to the null group:

Type :Ni! in Vim and be amazed, it’ll reply back: Do you demand a shrubbery?

Just how cool is that?

It’s been too long since the last time this image appeared on my blog:

I bet 90% of enterprisey architecture diagrams are more or less like this one.

From Geek and Poke

In the I bet somebody got a really nice bonus category, I found this one while trying to compile MySQL++ on Solaris: http://lists.mysql.com/plusplus/7811.

Don’t worry though. Now it’ll be renamed to #define ORACLE.

PS: Kind of related is the story about Oracle breaking everything after a %s/Sun/Oracle in the JVM [1], though in that case I’m more inclined to blame sloppy programmers.

[1] http://it.slashdot.org/story/10/07/28/2121259/Oracles-Java-Company-Change-Breaks-Eclipse

Remember:

Also, because otherwise this post would be empty:

It is a commonly accepted fact that a succesfuly compiled application serves as enough proof of its correctness, but common wisdom doesn’t say a thing about linking. If you like linker WTF moments, you’ll love this snippet. Can you guess why won’t it compile?

Well, it does compile (gotcha!) but it just won’t link. Yet it seems so simple… let’s add some more mistery to this WTF moment, try this change:

Holy shit, now it compiles? WTF? Some more strangeness:

And again, now it compiles. WTF? I’ll make a final change, this one should give you a clue about why it won’t compile. Revert all changes back to the original code but add this two lines after Foo:

Though weird at first, now you should have a clear picture:

• The first case doesn’t compiles: x and y are declared in struct Foo, yet the linker doesn’t know in which translation unit they should be allocated.
• The second and third cases… well I’m not sure why does this compiles but it’s probably because the linker can asume in which translation unit x and y should be allocated. I’m to lazy to check.
• In the last case we explicitly say where should x and y be. According to standard, this is how these two ints should be declared.

So, some linker strangeness. Beware, it’s easy to get trapped by this one.

Another one to add to my growing list of bad things about Ubuntu. For some reason my clock froze. I only noticed it when it started to be dark outside, for me the time had frozen at about 17pm.