Should I pass a shared_ptr by reference?
Should we pass a shared_ptr by reference or by value?
Is there a single word that describes both Witches and Wizards? In the Harry Potter world, there's the term "muggle" for people with no magical abilities, "muggle-born" for those with magical abilities who's parents are muggles and "squib" for those with no magical abilities who's parents are magical.  But is there any collective term for all magical people (as opposed to wizards for males and witches for females)?  I don't recall seeing any word that refers to all men and women and children with magical abilities, and it's the only group left without noun or collective noun to describe them. Find the center of the symmetry group $S_n$. Find the center of the symmetry group $S_n$.   Attempt:  By definition, the center is $Z(S_n) = \{ a \in S_n : ag = ga \forall\  g \in S_n\}$. Then we know the identity $e$ is in $S_n$ since there is always the trivial permutation. Suppose $a$ is in $S_n$, but not equal to identity. Now we can imagine the permutation as bijective function that maps from $\{1,2,\dotsc,n\}$ to $\{1,2,\dotsc,n\}$.  So suppose $p$ is a permutation map. Then $p$ maps from a location $i$ to a location $j$. Take $p(i) = j$ where $i\neq j$. Let $k$ be in $\{1,2,\dotsc,n\}$, where $k$, $i$ and $j$ are all different elements. The cycle $r = (jk)$, then we will see if this commutes.  $rp(i) = rj$    Can someone please help me, I am stuck?  Thank you. Given that , I wonder if every intelligent biological species is capable of producing beings that are Force-Sensitive?   Or are there some species characteristics that can make it 100% impossible for them ever to produce a Force-sensitive individual.  NOTE: Let's exclude - if they exist in EU - things like random new-species-creating mutations - e.g. the individual should be 100% the same species, able to interbreed. how can I reset a lost administrative password ,considering that Ubuntu and windows7 are both installed on the computer , considering also that "Boot up the machine,and after the BIOS screen, hold down the left Shift key." didn't logged me to any thing, just continue the loading of the system as normal?? Please show changed titles separately in edit diffs In an edit diff, when the revision changes the title, removed words are shown struck out in red and added words are shown with a green background. This is fine when there are only removed words, or only added words, but when there are both, the result is difficult to read.        Getting default accessible fields of… No. Getting accessible fields of an object in a Salesforce object… No. Getting accessible fields of a Salesforce object using REST API. Phew. Yeah, ok.        Program causes run. Time error? Oh, Program causes run-time error … when run on specific machine. Yeah, sounds sensible. What was the old title? Oh dear…  Please show both the old title and the new title, one below the other. How many points in RSA, such that $m^e = m \bmod n$ For every RSA-cryptosystem, there exist some messages $m$, for which it holds that $m^e \equiv m \pmod n$ As to the question, how many such messages exist, this question has already been asked and answered here:  However, I do only understand the answer up to a certain point Suppose that $n$ is only 1 prime. Then it holds that the number of unconcealable messages is $\gcd(e-1, p-1)+1$ This is because in $m^e \equiv m \pmod  p$ , either $m = 0$ or $m \not= 0$. In the latter case $m$ can be expressed as $g^t$, where $g$ is a Generator in $\mathbb{Z_p}$ $g^{t*e} \equiv g^t \pmod p$ $g^{t(e-1) \bmod p -1 } \equiv g^{0 \bmod p -1} \pmod p$ $t(e-1) \equiv 0 \pmod {p-1} $ has exactly $\gcd(e-1, p-1)$  solutions, so the total number of unconcealable messages is, together with $m=0$ , $\gcd(e-1, p-1)+1$ When we now look at real RSA, which has two prime factors in its modulus, it holds that the number of unconcealable messages is $(\gcd(e-1, p-1)+1)\cdot(\gcd(e-1, q-1)+1)$ Why is that so? I suppose it has to do with CRT, but I just cant understand why. Can a Linux user belong to more than one group?  If it is allowed, then one use may access files from two groups, that would be quite nice!  If not, is there any alternative way to have this function?  This issue is not the same as  or Why does C++ not let baseclasses implement a derived class' inherited interface? How to change an input button image using CSS So, I can create an input button with an image using &lt;INPUT type=&quot;image&quot; src=&quot;/images/Btn.PNG&quot; value=&quot;&quot;&gt;  But, I can't get the same behavior using CSS. For instance, I've tried &lt;INPUT type=&quot;image&quot; class=&quot;myButton&quot; value=&quot;&quot;&gt;  where &quot;myButton&quot; is defined in the CSS file as .myButton {     background:url(/images/Btn.PNG) no-repeat;     cursor:pointer;     width: 200px;     height: 100px;     border: none; }  If that's all I wanted to do, I could use the original style, but I want to change the button's appearance on hover (using a myButton:hover class). I know the links are good, because I've been able to load them for a background image for other parts of the page (just as a check). I found examples on the web of how to do it using JavaScript, but I'm looking for a CSS solution. I'm using Firefox 3.0.3 if that makes a difference. Are the contents of a loot box determined at the time it is awarded or when it is opened?  For example, if you collect multiple loot boxes before a special event but opened them during the special event, would they have the potential of spawning rewards from that event? When starring a message from the star board, it's not reflected in the main chat window If you click to star a post on the side (in the starred list), it changes color but not the star by the main chat area (it does add one to the number, but it doesn't change the color). Then when you click the star on the main chat area, it changes color to yellow but lowers the number by one  After clicking in sidebar:     After clicking in the main chat: First, … Secondly, … &c Take it for granted that enumerations have secondly, …; thirdly, …; finally, … Is there any reason, except tradition, to prefer the traditional first to firstly? There is no continuous injective function $f:\mathbb{R}^n\longrightarrow\mathbb{R}^m$ How do I set Titanfall in-game language to English (Russian version)? This question was initially about Russian PC version of Titanfall, available in Russian Origin store.  It appears that there exists a Worldwide PC version of Titanfall for which .  Tech support said that Russian users can only buy Russian version of Titanfall (both normal and Deluxe editions) and that they will not have any other in-game language available. They also offered me a refund, which I accepted.    I'm living in Russia and I recently pre-purchased Titanfall from here. My version doesn't have an option to select game language other than Russian.  Russian version has awful localization, many mistranslated technicalities and poorer game UI fonts than its English counterpart. Titan's on-board AI voice is pretty lame. The campaign briefing lines are cut off to fit the English files' length. Voice actors took liberty to change a few things to their liking. Audio effects like reverberation, echo and such are distinctively more basic. Overall audio quality is much lower, which greatly hinders immersion.  When I was playing open beta, it was all in English and considerably better. The game also doesn't support Russian characters so everyone is using transliteration in chat.  Switching Origin UI language to English didn't change the game's language. It's still all Russian.  How do I change Titanfall UI and audio to English?    Also: the support person didn't explicitly say tampering with localization files was against any rules or policy, so this may or may not be okay to do. Gotta find some hard info on that.  Although, adding launch parameters -language english, -language "english" in case of Russian version does not help. Players with other versions report that it does help.  As can be seen during game installation, the sound files alone take up about ~33 GB of disk space, and according to Origin's solution to Worldwide PC version, these files contain localization for every language available. It's just the rights to access them depend on version.    Note: it's important that the solution does not break any rules and is not outright illegal. Otherwise it may be removed from this site by a moderator, or, in worst case scenario, lead to some player's game and account being locked. So if you post something suspicious looking, be sure to include some links to official statements that allow such actions. How does an isolated body in deep space 'know' it's rotating? We can imagine an object floating in the known universe, maximally distant from any other large mass. Maybe it has been there since coalescing after the big bang.  What physical phenomena tell it whether it is rotating relative to the rest of the universe and therefore experiencing a centrifugal (?) force.  Is it the combined gravity of all other matter? Is it 'spooky action at a distance'?  Is it because it is rotating relative to 'empty space'? One of the big new features for Windows is the fact that multiple "virtual" desktops are now natively supported, allowing you to organise collections of windows together and separate groups of tasks.  This is good.  You can move windows between desktops by clicking the "tasks" button and then right clicking an application window and selecting "Move to..."  This is a bit clunky and not quite so good.  I have two monitors and often like to have a film playing on my second monitor, either in a web browser or media player, while I have a browser and some other applications on the main screen. Doing this isn't a problem in my current setup, it just works.   With the advent of virtual desktops I was wanting to put the browser on one virtual desktop and another app on another virtual desktop and still be able to watch the video when I switch desktops, effectively having it visible on both virtual desktops. Using the default Film &amp; TV app to play a video and then moving to another desktop simply results in your video stopping without any warning.   This is not good.  What I was hoping was that either the two monitors would have their own virtual desktop or their would be some "pin to all desktops" option similar to the "sticky window" feature that I have seen in many Linux based window managers.  Is there some way to achieve this? Let's say you want to save a bunch of files somewhere, for instance in BLOBs. Let's say you want to dish these files out via a web page and have the client automatically open the correct application/viewer.  Assumption: The browser figures out which application/viewer to use by the mime-type (content-type?) header in the HTTP response.  Based on that assumption, in addition to the bytes of the file, you also want to save the MIME type.  How would you find the MIME type of a file? I'm currently on a Mac, but this should also work on Windows.   Does the browser add this information when posting the file to the web page?  Is there a neat python library for finding this information? A WebService or (even better) a downloadable database? What does a linear transformation do to a vector in $\mathbb{R}^2$ $\newcommand{\Reals}{\mathbb{R}}$Doing some linear algebra. This question has me intrigued. I imagine it causes the vector to rotates the $x$ axis. But I mean, is there more to it?  $$ T_{A(\theta)}: \Reals^2 \to \Reals^2,\qquad A(\theta) =  \left[\begin{array} {rr}\cos \theta &amp; -\sin \theta \\   \sin \theta &amp; \cos \theta \\ \end{array}\right]. $$ What, geometrically, does the linear transformation $T_{A(\theta)}$ do to a vector in $\Reals^2$? Using Blender Game Engine for VR 360 tour on Mobile, is it doable? I'm sorry if my question sounds clumsy, I'm not a seasoned BGE user.  I'd like to make a virtual tour for Gear VR and/or Google Cardboard in the BGE that works on Mobile.  Is this doable in a user friendly way using the BGE? Can I export to Mobile (android, IOS, Windows Phone)? I know this is possible using Unity, but I find Unity difficult to use. I've tried UE4, but the process is a big mess, it requires a buggy multi-level hack that only results in wasting my time. Requires installation of untrusted packages?