That would measure how easy it is to perform arithmetic in the two systems... which is not the same as readability. Similarly it's a good idea not to confuse "easy for a computer to read (and execute)" vs "easy for a human to read (and understand)" - both are important in different ways, but they are entirely separate concerns!

QNX, not QMX. It's a hard-realtime microkernel OS. That doesn't mean it can do process control on its own, but the realtime features are handy if that is what you want to do with it.

LOL. Actually there's a better reason such a thread launch facility doesn't commonly get written - which is that, in most circumstances, it really doesn't help performance that much, if at all - and the added complexity makes for a big net minus. There are a number of issues:

Firstly, spawning threads is expensive. Yes, on Linux it's "cheap", but that's "cheap" compared to other implementations - it's still a lot compared to doing a modest amount of work on the local CPU. (Why is it so expensive? Basically because there's a lot of housekeeping to do. In addition to the kernel creating new kernel structures for the new thread of execution (similar to creating a process), the process's thread library must allocate a stack for the new thread (involving modifying the process's page tables), iterate through all loaded shared libraries in order to allocate any thread-local storage they require, and so on, requiring multiple syscalls, a TLB flush, at least one context switch, and so on. To some extent the impact of this overhead can be reduced by maintaining a pool of ready-created threads, but this either takes away control of performance (if done automatically by your language/library) or substantially increases complexity (if you implement it yourself, since you then have to synchronise the threads carefully).

The second problem is that, unless you're very careful, extra threads don't buy you much performance, and can indeed hurt. Take the example you gave - doing some processing on each struct in an array, where each such struct contains an int and a double (16 bytes total, including alignment padding). With 64-byte cache lines (typical on x86), there are 4 such structs per cache line. If you distribute the processing over threads running on different cores, then instead of one core waiting for the cache line to come in to main memory, and then processing the 4 structs very rapidly (since they're now all in cache), you'll have 4 cores each waiting for the data to be available - i.e. up to a 4x slowdown for memory-bound tasks. And that's assuming the structure is only read from; if it's written to as well then the cache line will have to bounce between cores, and the multithreading slowdown will be many times worse. Now, if you ensure that structs in the same cache line get processed by the same core (ideally in sequence, and by the same kernel thread), then you do potentially get a big speedup - provided you don't hit any other gotchas - but the C++ code you're promoting doesn't seem to guarantee this in any way.

Third, and perhaps most importantly, data dependencies matter. In your example you're detaching all the threads; this is not realistic, because that means you cannot ever depend on their operations having finished. In the vast majority of cases you do need to know when an operation has finished: you're generally doing work for a reason - i.e. that you're going to use the result - and you can't begin to use that result until you know it has been produced. That, in of itself, adds complexity: you have to analyse your program's dataflow much more carefully in the presence of threads, because C/C++ will quite happily let you use a variable before another thread has finished assigning to it, without any sort of warning or exception. The analysis can certainly be done, and synchronisation put in place to eliminate the problems - but that is further overhead, both in the program's performance but also in the complexity of the program itself, and hence the time taken to write it (and especially to enhance it later, when the synchronisation model may not be so fresh in one's mind).

Used correctly and in the right circumstances, threads on an N-core system can give a N-times speedup (or greater, due to caching effects). Used badly, at best they'll reduce performance, and usually they'll increase complexity and lead to subtle bugs that are hard to debug.

The new thread features in modern C++ are very cool, but the fact they didn't exist before is not what's been preventing competent programmers from using threads all over the place :)

The trouble is that, even with a UPS, my PC can decide to go bang of its own accord - so I need to solve that problem too :-/

Are you sure about that? Note the following (from the American Law Institute):

i.e. if you put terms into a contract that you know your customers aren't likely to agree to, then they're not binding, even if the contract is signed.

The majority religion in India is Hinduism; many adherents do not eat meat or eggs, but will generally eat dairy products, including cheese. So yes, vegetarian rather than vegan :-)

I couldn't find a source to back that up; instead, googling showed that the University of Utah prepared to enhance their security as a direct result of the threat. Or did I miss something? It's admittedly quite hard to search for without the results getting swamped with gamergate coverage of one sort or another...

I've missed all this... do you have any links?

I haven't seen any of this; do you perhaps have a link?

I did see that one (only once though); at least the idiot in question apologised...

Do you have any links about these?

I've got to confess I haven't seen any of this. Do you have a link?

There is another possible interpretation: that programmers who are very concerned about quality - and hence are happy when their language gives them lots of information about potential mistakes - like using languages with features (such as a strong type system) designed to allow detection of certain types of mistake. That is, it's specific features of the languages, rather than the fact that the languages are "unpopular", that draws quality-focussed programmers to them.

Of course, that is just as much conjecture as any other interpretation :-)

What I said was that there is no distance information in the message received from the satellite. Of course you can derive distance information, or else GPS wouldn't work at all :-)

Right - but there are two problems with this. One is that, by taking measurements over time, you do indeed get more information - but you also introduce more unknowns, because now you have to take into account the fact that you are likely to be moving - so you can't tell what part of the difference in the satellite signal is due to the satellite's motion, and which is due to yours. The other is that, even if you're guaranteed to be stationary, for your different readings from the same satellite to be useful, the satellite has to have moved a substantial distance, or else the errors in measurement will be relatively large compared to the change in timestamp difference - so you can't do an accurate calculation of your position. (This is why receivers won't give you a position readout even if they have 4 satellites, if those 4 satellites are very close together in the sky.) In practice it takes of the order of hours for the satellite to move sufficiently (which then introduces other problems - the quartz-based clocks in typical GPS receivers are not sufficiently accurate over such long periods.)

Yes - which is exactly what I said :-) But differences only give you N-1 measurements for N satellites.

Umm... if you're claiming you can find your elevation, then you can find your distance from the centre of the Earth. It's more or less the same thing :-). I agree you can use the measurements from the satellites though (i.e. you don't need to know any information about your elevation a priori).

I agree that the position of each satellite is known, to high accuracy. That's not the issue - the issue is that, if you have a signal from one satellite, that doesn't tell you your distance from that satellite. The signal basically says "I am satellite 7, I am at (position), and the time by my clock is (time)", and that is all your receiver receives. Receiving that signal tells you nothing about your position (well, possibly you can tell which hemisphere you're in from the fact that the satellite is visible at all, but that doesn't narrow things down much!). You only start getting information about your position when you have signals from more than one satellite, because then you can compare the timestamps - the difference in the timestamps gives you information about the difference in the distance from you to the two satellites.

I agree that 3 points and 3 distances is all you need. The trouble is that the signal from 3 satellites only gives you 2 distances (unless, as jfengel mentions, you happen to be carrying round an atomic clock with you - which is generally not practical!).

I mention probability because, even in the absence of 3 distances to give you a full 3D fix, you can use the fact that, statistically speaking, most people spend most of their time very close to the Earth's surface, to give a good estimate for one of the distances (i.e. estimate "I'm probably at or near ground level"), which then generally gives a pretty good estimate of your horizontal position. This is why even a 2D GPS fix is very useful in practice. But even if you have a signal from 4+ satellites, probability still comes into play: you have to account for radio interference, atmospheric effects and multipath effects, inaccuracies in the receiver's clocks, rounding errors, etc. etc., each of which adds uncertainty to the measurements and calculations and hence to the ultimate position readout.