Being a moderate time coder, I saw things like the following many times:  if (a != nullptr &amp;&amp; a-&gt;data != nullptr) {   // do something good with a and a-&gt;data }   However, I never really referred to documentation regarding such a simple case.     To my mind, the following is happening:   First, a != nullptr is checked Second, a-&gt;data != nullptr is checked   The thing now here is: if a != nullptr returns false and we have a conjunction via &amp;&amp; then there's no point to check the second statement a-&gt;data != nullptr being true or false:  since the first statement results in a false expression, the code inside the if-statement will not be executed, we don't need to check the second expression    But recently I have returned to the question yet again:  Is if safe to have a construction like this: if (a != nullptr &amp;&amp; a-&gt;data != nullptr) {}? Can it happen so that both* statements are checked and what I get is the nullptr dereference?  *- no multi-threading involved    What I'm asking is: is the above situation has a well defined behavior (and where can I find documentation for that) or this is generally UB that must be avoided? Is the behavior any different depending on the operating system (say, Windows vs. Linux-based)?
Does the ANSI standard mandate the logical operators to be short-circuited, in either C or C++?  I'm confused for I recall the K&amp;R book saying your code shouldn't depend on these operations being short circuited, for they may not. Could someone please point out where in the standard it's said logic ops are always short-circuited? I'm mostly interested on C++, an answer also for C would be great.  I also remember reading (can't remember where) that evaluation order isn't strictly defined, so your code shouldn't depend or assume functions within an expression would be executed in a specific order: by the end of a statement all referenced functions will have been called, but the compiler has freedom in selecting the most efficient order.  Does the standard indicate the evaluation order of this expression?  if( functionA() &amp;&amp; functionB() &amp;&amp; functionC() ) cout&lt;&lt;"Hello world";
Adding Image to a Polygon How do I install the latest OpenOffice? How can I backup my RAW photos while travelling without Internet access? This question seems similar to , but my needs are different :   I shoot in RAW exclusively I'm looking for a 100% offline solution: while traveling, Internet won't be accessible the "laptop" solution is too heavy for me: I'm looking for a lightweight solution the simplest, the better: one device to rule them all   EDIT:  I'm using good old Compact Flash cards (yes, the bigger ones), so I need a device that can read it. If it can read from other cards, this question might be interesting for more people than myself  - that's the whole purpose of the website.    Also asked by :  Portable Storage Device while traveling  I need storage device which is able to read CF cards and make a backup of my photos while traveling. I do not want to carry laptop (it's bulky) and tablet (too little storage) but looking into some other solutions.   So far I found:   Epson PXXXX - price is blocker for me Jobo Giga Vu - same as above Nexto DI - bit better, but still a lot Hyperdrive Colorspace UDMA - this looks the best for price/options Wolwerine PicPac - cheap, bad opinions DigitalFoci PhotoSafe - same as above Ex-Pro® Picture 2 Drive - didn't find much about it   So ladys &amp; gents what do you use? The conditions $a^2b^2=b^2a^2$ and $a^3b^3=b^3a^3$ make the group $G$ abelian? Drupal is fast at develop, but the performance is so poor.  It is hard to reach 50 request per second.  And there are so many SQL queries in a simple web page.  If you test the request time of a form submit in Drupal.org it will always take seconds to finish.  How do you improve the speed of your web site? Change MySQL default character set to UTF-8 in my.cnf? Is the Nintendo 3DS region-locked? I am thinking of buying a 3DS when the price drop comes into place in America, however I live in Australia. Will Australian 3DS games work on a North American 3DS? Two "offtopic" flag reasons How to make skill use on investigations "important" but failure not derail the plot? Well guys, following previous recommendations here I was able to build a Horror Themed Savage Worlds campaign that has made my players excited. However they're still getting used to the style, as well as I am. In order for them to hurt the major evils of the adventures they have to find their Form (physical appearance, name), Truth (How the creature came to be) and Reason (What the creature wants to), so they have to do research, kill lesser creatures, and run away from the big baddie of the adventure as they seek what it is.  Well, this is my problem:  How can I make them use skills significantly?  I'm used to railroading my players, even with mysteries, and I don't know how to put their skills for significant use. An example is, they usually require Streetwise or Investigation to gather clues and such, however, I wonder what to do if they fail the roll... If they fail they're not supposed to find anything, so chances they never finish the adventure are well, high, that and I have no idea how to give them additional, interesting ways for them to find the truth. So do I give it no matter what they rolled? How do I make use of their skills important and not just busy-work without having a failure on a roll completely stop their progress in the investigation? This is a  about avoiding outgoing mail being classified as spam.   Also related:                    I'm wondering how to prevent my emails from my site being marked as spam? I'm using sendmail.  I'm trying to send emails through my ruby-on-rails application. The mails are all written in swedish (if that does make a difference?). I don't know why they keep getting marked as spam.  Are there any things that I can do to minimize the risk? I just received a PhD invitation letter from a German University which mentions that my remuneration will be 2/3 of full TV-L 13 position. I do not know what a TV-L 13 position is (Google is of no help here), and didn't want to be rude, so I am asking here first. Is this a common position or specific to Germany? If anyone knows, currently how much remuneration corresponds to a TV-L position? Ubuntu Software not loading categories Asymptotic expansion for Fresnel Integrals If you take the fresnel integrals to be $$S(x) = \int_{0}^{x}\sin \left(\frac { \pi \cdot  t^2}{2} \right) dt$$ How do you find the asymptotic expansion? I know it begins with a $1/2$ but how? How do I recover or "undelete" files that I accidentally deleted? I've accidentally deleted some really important files on my machine, and I'm looking to find out how to recover them.  Using the Trash bins "restore" isn't an option, as the files aren't there (mostly likely I wasn't paying attention and permanently deleted them from there).  Is there any way that I can un-delete these files? Is there a difference between "Joe said" and "said Joe"? Does the subject/verb order make a difference when writing a dialog tag?  &quot;The sky is blue,&quot; Joe said. &quot;The sky is blue,&quot; said Joe.  Is one preferable over the other? Does one emphasize the speaker (or the method of speech, such as shout) more than the other? (Personally, I would use the second form to emphasize that Joe made the statement) My port of entry and exit is Frankfurt, Germany. However i will only be spending a day or two there. I am visiting Spain and Portugal for a week each. So should I be applying to Spain embassy or German embassy? I am an Indian citizen. Limit of Multivariate Probability Density Function as one or more or all variables approach positive or negative infinity Could someone point out a good source or provide justification as to whether the limit of a multivariate probability density function, as one or more or all variables tends to positive or negative infinity, goes to zero.  $$\lim_{x_{1}\to\pm\infty}f(x_{1},x_{2},...,x_{n})=0$$  $$\lim_{x_{1},x_{2}\to\pm\infty}f(x_{1},x_{2},...,x_{n})=0$$  $$\lim_{x_{1},x_{2},...,x_{n}\to\pm\infty}f(x_{1},x_{2},...,x_{n})=0$$  I have found this related question for the univariate case: How do I get query string value from script path? how to reset a lost admin password? How can I install Ubuntu 13.04 + without USB, CD, DVD or Net? (hard drive only) I have an older i386 Sony Vaio desktop PC where the BIOS only allows boot from floppy, CD or very specific USB device types, none of which seem to recognize USB flash drives for some reason. Floppy is not an option because the drive no longer works and I have no media for it if it did. I've tried assorted CD and DVD drives, the CD drives all give read errors and DVD drives all say "unsupported emulation".  My next possible option that I would like to try, is to install the hard drive into another machine as a second HD and figure out a way to format it and save an Ubuntu installation to run from that HD once it is moved back into the target machine. IS this possible and if so, how would I go about doing so? The currently running machine uses Windows XP.