Why we have to use new operator?
Why aren't variable-length arrays part of the C++ standard?
A quark star is a hypothetical type of compact exotic star composed of quark matter. These are ultra-dense phases of degenerate matter theorized to form inside particularly massive[citation needed] neutron stars. -Wikipedia   If you add enough mass to a neutron star it forms a black hole but how much mass is needed to form a quark star? When do neutrons and protons start to break down into a mush of quarks and gluons? On the recent changes to flagging and limits Looks like flagging has been affected by releases today. Are these intended effects?   Higher daily limits (appear doubled for me, flagging of posts limit also doubled).  Explained by Shog9 below. Soft comment deletion  - e.g. for "accept rate" obsolete comments - it does in fact work, but the immediate feedback is gone.  This is fixed now. Has the throttling rate changed?  Seems possible to repeated flag without waiting 5 seconds.  If it was broken, it isn't anymore. Old soft deletions that were neither categorised as "helpful" or "declined" have all become "helpful".   If limits have been updated, can we get the new formula published? Not changed, as confirmed by Shog9. How do I translate strings in Twig templates? I am working on a (my first) Drupal 8 project witch is a multilingual site. Drupal 8 really delivers in terms of native support for content translation.  However, I have a few strings set directly in some if the theme .Twig template files printed out like ex.   {{ 'Read more'|trans }}   I am really stuck on where to handle the translation for strings like these within the Drupal 8 installation.  What steps do I need to take to be able to translate these strings into the language currently selected for on the site? Do I need any additional modules other than the ones included in Drupal 8 core?  Steps I have taken:   Activated the Content Translation &amp; Interface Translation modules Added Twig strings like {{ 'Read more'|trans }} Flushed cache and refreshed pages containing the strings Checked admin/config/regional/translate for the strings with no result How can I control a servo motor with the PWM output of a microcontroller? I wanted to control the direction of servo motor with a switch. I am using an Atmega32.  Outputs are PIND4 and PIND5 and the input is PINA3, but the two servo motors turn only in 1 direction.  #ifndef F_CPU  #define F_CPU 1000000UL   #endif  #include &lt;avr/io.h&gt; #include &lt;util/delay.h&gt; #include &lt;avr/interrupt.h&gt;   int main(void) { DDRD= 0xFF ; DDRA=0x00; PORTA =0x00; // FAST PWM TCCR1A |= 1&lt;&lt;COM1A0 | 1&lt;&lt;COM1A1 | 1&lt;&lt;WGM11 |1&lt;&lt;COM1B0|1&lt;&lt;COM1B1 ; TCCR1B= 1&lt;&lt;WGM12|1&lt;&lt;WGM13 ; ICR1 = 19999 ;  TCCR1B |=1&lt;&lt;CS10 ; while (1) {    if(PORTA==0x08) //if pina3 is 1    {     OCR1A = ICR1 -2000 ;   //turn servo 1     _delay_ms(1000);          OCR1B=ICR1-2000;    //turn servo 2     _delay_ms(1000);     }     if(PORTA==0x00)// if pina3 is 0     {       OCR1A = ICR1 -900 ; //turn servo 1 in the other direction       _delay_ms(1000);               OCR1B=ICR1-900;     //turn servo 2 in the other direction       _delay_ms(1000);      } }       return 0 ;  } Metrizable topological space $X$ with every admissible metric complete then $X$ is compact How to prove:      If $X$ is a metrizable topological space and every admissible metric on $X$ is complete then $X$ is compact.    I was trying with an idea of contradiction and thereby to construct an incomplete metric on $X$. But not able to construct. It is well known that $\sqrt{2}$ is irrational, and by modifying the proof (replacing 'even' with 'divisible by $3$'), one can prove that $\sqrt{3}$ is irrational, as well.  On the other hand, clearly $\sqrt{n^2} = n$ for any positive integer $n$.  It seems that any positive integer has a square root that is either an integer or irrational number.        How do we prove that if $a \in  \mathbb N$, then $\sqrt a$ is an integer or an irrational number?      I also notice that I can modify the proof that $\sqrt{2}$ is irrational to prove that $\sqrt[3]{2}, \sqrt[4]{2}, \cdots$ are all irrational.  This suggests we can extend the previous result to other radicals.        Can we extend 1? That is, can we show that for any $a, b \in \mathbb{N}$, $a^{1/b}$ is either an integer or irrational? How do I print a double value with full precision using cout? What is the appropriate statistical test when calculating the busiest day of the week? We have 10 years of data and Monday is the busiest (most visits to the hospital) on average. If we wanted to assess whether that is true and report a p-value, what is the appropriate statistic?   We believe the answer is chi-square as we found a peer-reviewed medical article from the Annals of Emergency Medicine (highest circulating journal for that specialty) that used chi-square for this very calculation.   If chi-square is appropriate, what values do we use for observed and expected values for chi-square? One approach would be to list all the values for Monday as observed values, or all the means for Mondays averaged across a month, or all the means for Mondays averaged across a year.  If there were no busiest or least busy days, we would assume that the visits would be the same every day of the week. That means our "expected values" for Chi-Square would be the mean of the visits for any given week. How can I script the settings made by gnome-tweak-tool? I like to be able to configure things from the command line, so that when I reinstall the OS I can just run a script and get my preferred configuration back.  Since "upgrading" to Ubuntu 17.10, I found I had to use gnome-tweak-tool to get some settings the way I want them.  Once I find a setting in the gnome-tweak-tool GUI, how can I figure out its scriptable translation?  For example the following gsettings lines match the relevant entries in the gnome-tweak-tool screen shot below...  gsettings set org.gnome.desktop.wm.preferences titlebar-font "Tahoma Bold 8" gsettings set org.gnome.desktop.interface font-name "Tahoma 8" gsettings set org.gnome.desktop.interface document-font-name "Tahoma 8" gsettings set org.gnome.desktop.interface monospace-font-name "FixedSC 10"    ...but how could anyone guess that? And how would I, for example, figure out where to get the corresponding settings for hinting and antialiasing? If I have bought 3 tickets for the same flight, can I bring three times the cabin allowance allowed per ticket?  The way I see it I am doing the airline a favor  Related: Does it mean neither a muslim nor a pakistani anymore? Or it means muslim and ex pakistani. I will be very thankfull if you people kindly elaborate this for me. I am very confused. Unless I am mistaken, I know "it" has to be a noun of some sort, but I am unable to figure out what noun "it" is referring to.   What is "it" in the following sentence:      It is clear that Bob likes doughnuts.   Heres another couple of examples:     It is impossible to fly. Creating a query that uses criteria from two tables? Sort arrays of primitive types in descending order I've got a large array of primitive types (double). How do I sort the elements in descending order?  Unfortunately the Java API doesn't support sorting of primitive types with a Comparator.  The first approach that probably comes to mind is to convert it to a list of objects (boxing):  double[] array = new double[1048576];     Arrays.stream(array).boxed().sorted(Collections.reverseOrder())…   However, boxing each primitive in the array is too slow and causes a lot of GC pressure!  Another approach would be to sort and then reverse:  double[] array = new double[1048576]; ... Arrays.sort(array); // reverse the array for (int i = 0; i &lt; array.length / 2; i++) {      // swap the elements      double temp = array[i];      array[i] = array[array.length - (i + 1)];      array[array.length - (i + 1)] = temp; }   This approach is also slow - particularly if the array is already sorted quite well.  What's a better alternative? how to change landscape mode Ideally, I'd like to write a unit test to help me "dummy check" for unexpected effects of the upcoming guest user sharing setting changes.  We'd had some controller/trigger code "gracefully handling" data it couldn't see thanks to the new sharing restrictions ... which resulted in simply "not doing" some work that it was supposed to do, which from a business process perspective isn't "graceful" at all (it was an important automation for downstream processes).  I'd like to write up a unit test with some system.assert statements validating that "data still goes where it's supposed to" when the "submit" button a public-facing Visualforce page of a community is clicked.  Unfortunately, I can't seem to make the "submit" button on a Controller for a public-facing Visualforce page work in the context of a unit test because the record whose creation it results in doesn't get its corresponding "sharing setting" record created in time for the execution context to pick it up.  I did a little proof of concept here ...  @isTest public class TestClass {      private static Id guestProfileId = Util.getProfileIdByName('Public Facing Portal Profile');     private static User guestUser;     private static Id portalGroupId = [SELECT Id FROM Group WHERE Name = 'Public_Portal' LIMIT 1][0].Id;      private static Custom_Object__c co;       private static testMethod void runTest() {         createCO();         Test.startTest();         // Note that putting createCO() inside the test and doesGuestSharingRuleExistForCO() doesn't help.         // That's what I was afraid of.         try {             doesGuestSharingRuleExistForCO(co.Id);         }         catch (Util.DeveloperException e) {             System.assert(FALSE, e.getMessage());         }         Test.stopTest();     }       private static void cacheUsers() {         guestUser = [SELECT Id FROM User WHERE profileid = :guestProfileId AND IsActive = TRUE LIMIT 1][0];     }      private static void createCO() {         co = new Custom_Object__c();         INSERT co;     }      private static void doesGuestSharingRuleExistForCO(Id coId) {         List&lt;SObject&gt; existingSharingRulesOnCO = [             SELECT Id FROM Custom_Object__share             WHERE RowCause = 'GuestRule' AND AccessLevel = 'Read' AND ParentId = :coId AND UserOrGroupId = :portalGroupId LIMIT 1         ];         if ( existingSharingRulesOnCO.isEmpty() ) { throw new Util.DeveloperException('Guest User sharing is not on for this custom object ID'); }     }      private static Boolean isCOSharingFlippedOnAtAll(){         String lookingFor = 'Custom_Object__Share';         for (Schema.SObjectType sObjectType : Schema.getGlobalDescribe().values() ) {             String sobjName = String.valueOf(sObjectType);             if (sobjName.contains(lookingFor) ) { return TRUE; }         }         return FALSE;     }  }   Am I just out of luck?  Is there no way to properly unit-test the effects (to automations relying upon "guest user" sharing settings when running as "guest user") of simulating the insertion of records into my database from a Visualforce page, due to not being able to separate out "execution context" enough and "wait" for the sharing rule record for the new record to come into existence? Subject vs. Object marking for whoever? I know similar questions have been asked before, but I'm having trouble reconciling the following sentence, received in an email:     Can we ask whomever is your contact there to email us a job so we can check backward compatibility?   I could understand using objective case if the sentence were "can we ask (him) to email...", but I get tripped up considering "whomever" to be the subject of "(he) is your contact there". Can anyone explain IEnumerable and IEnumerator to me? Can anyone explain IEnumerable and IEnumerator to me? For example, when to use it over foreach? what's the difference between IEnumerable and IEnumerator? Why do we need to use it? We had in our lecture on numerical analysis the following: Let $\mathrm{Lin}(X,Y)$ be the set of all linear maps $X\rightarrow Y$. Let $A\in\mathrm{Lin}(\mathbb R^l,\mathbb R^n)$ and $B\in\mathrm{Lin}(\mathbb R^n,\mathbb R^m)$ and $\|C\|_{op}:=\max_{\|x\|\leq1}\|C(x)\|$. Then our lecturer followed $\|A\circ B\|_{op}\leq\|A\|_{op}\cdot\|B\|_{op}$. So he didn't prove it and so I've tried it by my own. My attempt: $$\begin{aligned} \|A\circ B\|_{\mathrm{op}} &amp;= \max_{\|x\| &lt; 1}\|(A \circ B)(x)\| \\ &amp; \leq \max_{\|x\| &lt; 1} \|A\|_{\mathrm{op}} \|B(x)\| \\ &amp;= \|A\|_{\mathrm{op}} \max_{\|x\|\leq1}\|B(x)\|\\ &amp;= \|A\|_{\mathrm{op}}\|B\|_{\mathrm{op}} \end{aligned}$$ But this seems too easy. I am really interested in a nice proof so anybody could help? Thanks a lot! According to general relativity, inertial mass and gravitational mass are the same, and all accelerated reference frames (such as a uniformly rotating reference frame with its proper time dilation) are physically equivalent to a gravitational field of the same strength.  Refer: Einstein's thought experiment of a Physicist in an Accelerated Box.  I find that the 'How' part of this question is somewhat easy to understand Mathematically but hard to visualize physically and on the 'Why' part I am totally blank.