Why can I call destructor on a fundamental type in a template? I was implementing some templates for a memory allocator and came across some code that's compiling that I expected to not compile.  After writing and testing a template function to call a destructor, I found that it still worked after passing in an int*.  Test code:  #include &lt;iostream&gt;  template&lt;typename Class&gt; void CallDestructor(Class* InObj) {     InObj-&gt;~Class(); }  int main() {     int* test = new int;     *test = 5;     std::cout &lt;&lt; *test &lt;&lt; std::endl;     CallDestructor(test); // Why does this compile?     //test-&gt;~int();       // This does not compile which is what I expected for template function     std::cout &lt;&lt; *test &lt;&lt; std::endl;     delete test; }   The code compiles and runs on www.cpp.sh and also in Visual Studio 2013 for me.  Thank you for any insight!
Destructors of builtin types (int, char etc..) In C++ the following code gives a compiler error:  void destruct1 (int * item) {   item-&gt;~int(); }   This code is nearly the same, I just typedef the int to another type and something magic happens:  typedef int myint;  void destruct2 (myint * item) {   item-&gt;~myint(); }   Why does the second code work? Does an int get a destructor just because it has been typedefed?  In case you wonder why one ever would like to do this: This comes from refactoring C++ code. We're removing the standard heap and replacing it with selfmade pools. This requires us to call placement-new and the destructors. I know that calling destructors for primitive types is useless, but we want them in the code nevertheless in case we later replace PODs with real classes.  Finding out that naked int's don't work but typedefed ones do was quite a surprise.  Btw - I have a solution that involves template-functions. We just typedef inside the template and everything is fine.
How to install MariaDB? Show that $n$ lines separate the plane into $\frac{n^2+n+2}{2}$ regions What is the relation between linear purity and von Neumann entropy of a state? Given a density matrix $\rho$, its linear purity is $\mathrm{Tr} \rho^2$, its von Neumann entropy is $-\mathrm{Tr} \rho \log \rho$. Knowing one how do I calculate the other?  Edit:   My thought is that the linear purity and the von Neumann entropy are a parallel set of benchmarks for mixedness. Their inter-conversion should be like unit conversion.  See it this way, as a state goes from a pure state to a maximally mixed state, $\mathrm{Tr} \rho^2$ goes from $1$ to $0$, and $-\mathrm{Tr} \rho \log \rho$ goes from $0$ to $\log d$, like two rulers. A point on one should correspond to a point on the other. Is there a ".bashrc" equivalent file read by all shells? Is ~/.bashrc  the only place to specify user specific environment variables, aliases, modifications to PATH variable, etc?  I ask because it seems that ~/.bashrc seems to be bash-only, but other shells exist too… How do I install an SSH private key generated by PuTTYgen? Copy files from a list to a folder In a file with lots of lines I want to delete lines that starts with HERE IT IS.  How can I do this using only command-line tools? From the user's perspective when switching on the phone, I see two boot animations in my  running CM10. The first animation is from LG and the second animation is from CM10. Then it settles in with a locked screen ready for my input. What happens behind the scene (screen) during a boot process when an Android device is switched on? It will be helpful if the answers can help a non geek to understand various process and jargon (like, fastboot, bootloader, recovery, if applicable, etc.) regarding boot sequence. Is it a goal if, during kicks from the penalty mark, the ball goes outside the penalty area and then into the goal? ArrayList vs List I saw this reply from Jon on :     If you want a single collection to   contain multiple unrelated types of   values, however, you will have to use   List&lt;object&gt;   I'm not comparing ArrayList vs List&lt;&gt;, but ArrayList vs List&lt;object&gt;, as both will be exposing elements of type object. What would be the benefit of using either one in this case?  EDIT: It's no concern for type safety here, since both class is exposing object as its item. One still needs to cast from object to the desired type. I'm more interested in anything other than type safety.  EDIT: Thanks Marc Gravell and Sean for the answer. Sorry, I can only pick 1 as answer, so I'll up vote both. For x < 5 what is the greatest value of x It can't be $5$. And it can't be $4.\overline{9}$ because that equals $5$. It looks like there is no solution... but surely there must be? Implement numbering scheme like A,B,C... AA,AB,... AAA..., similar to converting a number to radix26 I want to implement numbering scheme like Microsoft Word uses for numbering.  first one gets = A,next is  B, next is C, .... then AA, then AB,....and so on.  as shown below   A        B  C  .   .  AA  AB  AC  .  .  AAA  AAB  ....   '=>' here means converted to.  some examples:       1 =&gt; A 26 =&gt; Z 27 =&gt; AA 52 =&gt; AZ 53 =&gt; BA   and heres the code for it:     var convertToNumberingScheme = function(n){         var x = n-1,             r26 = x.toString(26),             baseCharCode = "A".charCodeAt(0);          var arr = r26.split(''),             len = arr.length;          var newArr =arr.map(function(val,i){             val = parseInt(val,26);              if( (i === 0) &amp;&amp; ( len &gt; 1)){                 val = val-1;             }              return String.fromCharCode(baseCharCode + val);         });         return newArr.join('');     }   It seems to work fine, but any ideas if there are some potential bugs or ways to  optimize this. Limit of a stochastic integral Why is $a^n - b^n$ divisible by $a-b$? I did some mathematical induction problems on divisibility   $9^n$ $-$ $2^n$ is divisible by 7. $4^n$ $-$ $1$ is divisible by 3. $9^n$ $-$ $4^n$ is divisible by 5.   Can these be generalized as $a^n$ $-$ $b^n$$ = (a-b)N$, where N is an integer? But why is $a^n$ $-$ $b^n$$ = (a-b)N$ ?  I also see that $6^n$ $- 5n + 4$ is divisible by $5$ which is $6-5+4$ and $7^n$$+3n + 8$ is divisible by $9$ which is $7+3+8=18=9\cdot2$.  Are they just a coincidence or is there a theory behind?  Is it about modular arithmetic? Word for giving animal characteristics (esp. physical ones) to humans I am writing a paper about Art Spiegelman's Maus, specifically the metaphor that Spiegelman creates by depicting his obviously quite human characters with the heads of various animals, or a couple times animal masks. The metaphor is used at times to bestialize/animalize the acts of the Nazis and, in some cases, to show the arbitrary nature of the classes/groups/divisions they and others applied to human beings.  I considered "chremamorphism," but this describes the attribution of the characteristics of an object to, or the objectification of, a human. I also considered "animalize" and "bestialize," but those describe some of the effects that can be produced by Spiegelman's metaphor, not the metaphor itself - in many scenes in the book, the characters are extremely human, and I think that the negative or degrading connotations of these words makes them inappropriate for this use. Nor do "anthropomorphism" or "personification" fit, because Spiegelman is not applying human characteristics to animals but the other way around. None of the words that I can think of quite fit.  What is a word that accurately describes Art Spiegelman's depiction of obviously human characters as having animal body parts or wearing animal masks in the comic book Maus? PuTTY inserts random characters during a session I recently started renting space on a remote server so that I could work on a project. I found that a relatively painless way to access it on a windows machine is through PuTTY. However, there is one thing that has always irked me when using it: for seemingly no reason random characters are sometimes inserted at the cursor.  Most of the time it is just a single tilde, but rarely it spits out what looks like some escape sequence ([[^8 or the like). It will only occur when I am focused on the window, whether I am typing or 20 feet away from the keyboard. If left for long enough, it will spit tildes at random intervals (average is about 1 minute).  Finally, this behavior seems to be inconsistant when running programs such as nano or the mysql interface: in nano, instead of inserting tildes, it will set marks (ctrl-^); in mysql, lines will become un-editable.  My question is this: Has anyone else experienced this sort of behavior in PuTTY? And if so, what can be done to prevent/correct this behavior? Why can't the indefinite integral $\int\frac{\sin(x)}{x}\mathrm dx$ be found? I came across a list of functions in my calculus textbook whose indefinite integral cannot be found. It was written that the integral $$\int \frac{\sin(x)}{x} dx$$ cannot be evaluated without any explanation as to why.  I did some research over the internet and found out that the definite integral $$\int_{0}^{\infty} \frac{\sin(x)}{x} dx$$ can be evaluated using Laplace transformation and is equal to $\pi /2$. But I still couldn't find answer to my original question. I read somewhere that the integral cannot be expressed using 'elementary functions'. A little help is appreciated, I'm in Calc 1 going advanced than my course but I am sorry if my post shows lack of research. Thank you! a command to list all packagas installed on the system and their installed files, how? How do I read image files directly from a zip without extracting to disk? Does shoving a creature break its grapple on another? A situation came up in my session where a fighter used his Shield Master Shove feature to shove a Giant Crocodile that was currently restraining another PC using it's bite+grapple ability.  I did a quick check at the time and did not find anything related to shove, although in the  condition description it states:     The condition also ends if an effect removes the grappled creature from the reach of the grappler or grappling effect, such as when a creature is hurled away by the thunderwave spell.   I ruled at the time that a shove would count in a similar way to being "hurled away" however I wasn't sure and said I would find more concrete information for the future.  I have searched high and low for somebody else asking this specific question but have yet to find it. I saw some reference to a Jeremy Crawford tweet about involuntary movement and grappling however I am unable to find it.  If a third party "shoves" a creature that is grappling another, does it only shove the grappler away, or does it move both the grappler and grappled?  I drew a diagram:   (; this question relates to if a third party shoves the grappler instead, so it's not a duplicate.)