The monkeys Speak

automatic type promotion in c++

kristo — Fri, 30 Sep 2011 08:52:33 +0000

At work, we got into a bit of a discussion, about how c++ compilers do automatic promotion of variable types, because it is somewhat unexpected sometimes (did you know, that if you do if(variable of type unsigned char), it gets promoted to int?)

So, how and if is prmotion done for signed/unsigned mismatches. Well, here a re a few test programs:

test1:

#include

int main(void)

{

unsigned int a = 3000000000;

if (a > -2)

{

printf(“yes!\r\n”);

}

return 0;

}

result: as expected, nothing is printed, since there really is no way for this to work anyway.

test2:

#include

int main(void)

{

unsigned int a = 4;

if (a > -2)

{

printf(“yes!\r\n”);

}

return 0;

}

result: the same, although the compiler could have made this work theoretically.

test3:

#include

int main(void)

{

unsigned int a = 4;

signed int b = -2;

if (a > b)

{

printf(“yes!\r\n”);

}

return 0;

}

result: the same, which does make sense, since no automatic promotion is done in this case.

now, for the really surprising bit hough:

what switches are needed for gcc to warn you about this?

I assumed, -Wall is enough, but no. So I tried -Wall -pedantic, but to my great surprise, still nothing!

Apparently you need the -Wextra switch for this to generate a warning about comparing signed and unsigned values!

Say it with me!

kristo — Tue, 08 Feb 2011 08:09:19 +0000

If you trust yourself and believe in your dreams
and follow your star, you’ll still get beaten by people
who spent their time working hard and
learning things and weren’t so lazy.

–Terry Pratchett, The Wee Free Men

Damn straight YO!

content or no content. there is no question.

admin — Tue, 25 May 2010 09:50:29 +0000

have to say – business class is the only way to fly

no, really, even on estonian air – the airline recently voted as having the worst meals in the history of all airlines. which I don’t agree with by the way.

to look at it heartlessly and only considering the true facts – yes, the seat is the same and the legroom is the same and on this particular plane there isn’t even a curtain to separate you from the rest of the plebeians (not that it makes much difference, but damn it makes you feel superior), but there is just something very nice and relaxing about looking out the window at clouds passing by 5 kilometers below you while a stewardess inquires if perhaps sir would like some more wine.

but I have to think about why that mekes me feel good. is it just the feeling of superiority (although I am here only by accident – usually my company flies me coach as does every other company I know of) or is it really better to get a sandwitch instead of a roll? empirically, of course, the difference in the actual food is minimal. there is the aspect of free booze of course and it just might be the influence of alcohol that makes all the happy juice. but, for the sake of argument, let’s say that it isn’t and look at the other possibilities.

so – the small difference in food or being seated separetely from the people who have the cheap tickets. the essence of them is of course the same – you are better than them and they can see it. you are at the top of the pack. but of course I’m not really at the top of the pack, in fact the real top is so far away I couldn’t even see it if I could somehow get access to the hubble telescope. wo, what this really is about, is desception – make things seem like they are better than they really are.

to sum up so far: I am being fooled into thinking that things are going really good for me and I am being treated like royalty and that makes me feel really good. this little theatrical play really works.

but why? I am a fairly intelligent person – I should realize that this is just a sham and should even perhaps be insulted by this sharade. for the flex ticket I got a different sandwitch, a glass of wine and a small bottle of whiskey – even the most adventurous restorant owner would not be able to justify charging an extra 3000 EEK for those things. of course, it isn’t really MY money, it’s moy employer who’s paying for it, but still.

from this it would seem that there is no real tangible difference between being fooled into feeling superior and actually being superior. another proof to the postulation that “manufactured” happiness is the same as real happiness. as some philosophe said – we only see shadows of the real world and what we percieve as reality is really only going on inside of our own heads. each of us creates their own little universe in their head and with just a small nudge from the outside world we can be the kings of our own universe.

making a product or service that induces this feeling in me, thus enables me to feel like a king. what are the properties that a device needs to have to induce in me this feeling? if we base our reasoning in the airplane industry, then it seems, that it doesn’t really matter if the content is much better (ham sandwitch in business class versus a bacon roll in coach) or different, but the way it is presented is what sets it apart. the stewardess here smiles at me and does try to make me feel as comfortable as possible. I feel more comfortable, but in every measurable aspect I am only as comfortable as everyone else on the plane.

this is of course what apple and google have figured out as well – make things that look good and are comfortable and intuitive to use, not things that break new ground technologically. using devices or software like that makes me feel in control, like I am the boss. like a king.

it seems to me, that during this flight I really have managed to convince myself here, that presentation really IS content.

happy flight experiences,
the flying monkey.

“The space shuttles’ retirement follows almost 30 years of service and will after September leave the US without any major way of launching astronauts into space”

admin — Tue, 06 Apr 2010 09:49:34 +0000

I like rockets. Really, space is way cool! After the iron curtain opened and information about the outside world started coming in, I started hearing about NASA and the cool rockets they send to space and the astronauts who fly them. And ever since that it has always been my opinion that working for NASA is the ultimate job for common people, being an astronaut the job that every single person who wants to be the best in the world should strive towards.

I have always dreamed that when my son is maybe 7 or something around that age, we’d go take a trip to the US and see a shuttle launch and then I could point to it taking off and say that look, son, there’s people in that thing and they are going into space. They are doing the greatest thing any person in the world can possibly do. And if you study real hard and make the right choices, there is a chance that you will be able to do that as well some day.

And today my dream was broken, because it seems they really are going to end the shuttle flights – the last one is scheduled to take off in September. It will probably be extended a bit, but not the four years it will take for my son to turn seven. After that the ISS servicing crews will be launched by Russian rockets from Baikonur, I believe. And for an Estonian, getting into that program, the chances are 0% unfortunately.

There is some hope, that commercial space launches will start to happen, but that is still probably a decade away as well.

This is a sad time for the people of the earth.

http://www.networkworld.com/community/node/59718

this will be the new code monkey card

admin — Wed, 31 Mar 2010 09:48:57 +0000

oh, those open-source developers. they are all about fun-fun-fun!

admin — Tue, 30 Mar 2010 09:46:26 +0000

I just found these two macros in the jffs2 filesystem implementation in ecos:

#define JFFS2_INODE_INFO(i) (&(i)->jffs2_i)
#define OFNI_EDONI_2SFFJ(f) ((struct _inode *) ( ((char *)f) – ((char *)(&((struct _inode *)NULL)->jffs2_i)) ) )

oh boy, someone was having a good day

man, that schneier dude is smart

admin — Thu, 10 Dec 2009 09:45:38 +0000

just read this: http://www.schneier.com/essay-114.html

your friendly neighborhood privacy-monkey.

give up and use tables.com

admin — Wed, 18 Feb 2009 13:26:02 +0000

I am a programmer. always have been. In the dark old days of yesteryear, I was the kind of guy, who thought that javascript is the language of hell and css and div’s are for people with tiny brains, who find a couple of nested

Then one day I was pointed towards a javascript library, called JQuery and from that day on, nothing has ever been the same to me again. This really was the fix that javascript needed in my opinion – a well-defined set of methods that work on all browsers and work exactly the same. Of course, I understand that this could not have come from any single browser manufacturer or even the w3c – it had to be an independednt effort. And so it was, as the old saying goes – “any problem in computer science can be solved with another layer of abstraction” that the problem with javascript was solved. Now you could do lots of clever things with layers and it would actually work the same on any browser! YAY!

So I decided to learn javascript properly. It seemed to be ok at first, all the dynamic typing and other details seemed just fine. And then I read about prototypes and went – WOW – this is what has been missing from my life all these years! It’s brilliant!

And it was. And still is. I also read that javascript was basically invented and implemented at first by one guy, working at netscape. Remember this, because it will be important later.

Now, the next logical step after learning javascript is – learn xhtml and css properly. Forget about tables and single pixel gifs forever. (unless presenting tabular information, of course!)

So I decided to gove that a try as well, being excited about having learnt javascript and seen the greatness that it is, I figured css – being at it’s third version and all would be quite mature and awesome by now.

Oh boy was I in for disappointment. Just to give a small example: make a

and now, center an image inside it. or some text. or bloody well anything. Horizontally, you can, quite easily, but vertically – no. it is just impossible (you can do it if you know the heght of the item inside, but you can’t portably if you don’t). Honestly, I was just flabbergasted when I found this out. Unbelievable.

How can this be – probably hundreds of people have spent years designing this thing, the standard is hundreds of pages long and still I can find several items that are not well defined in the first 30 minutes or trying to use it. Perhaps it is just another proof of the theorem that design by committee does not work, but it seems to be even more than that. I can’t even think what exactly – Ignorance, just plain stupidity … ? Honestly, it is just awful.

Of course, some time later, I found a website http://giveupandusetables.com and have been happy ever since.

So what is the moral of the story? Simple, really – try new things but be prepared for the possibility that they suck and you will have to go back to the good old ways and use the things that have always worked, because they were created to scratch an itch somebody had, not by a committee that thought it is the right way to do things. So, no xhtml for me, thanks very much and welcome back, html 4.01 transitional.