I have the following code   template&lt;typename VP,bool b&gt;   class ValueProcessor{     template&lt;typename Access,typename X&gt; void processValue(X&amp; x){}   };     template&lt;typename VP&gt;   class ValueProcessor&lt;VP,true&gt;{   public:     template&lt;typename Access,typename X&gt; void processValue(X&amp; x);   };    template&lt;typename VP&gt;     template&lt;typename Access,typename X&gt;    void ValueProcessor&lt;VP,true&gt;::processValue(X&amp; x){     class Updater{       ValueProcessor&lt;VP,false&gt; valPro;       X x;     public:       void operator()(){         valPro.processValue&lt;Access,X&gt;(x);       };     };   }  but it fails with this error     source&gt;: In member function 'void ValueProcessor&lt;VP, true&gt;::processValue(X&amp;)::Updater::operator()()': &lt;source&gt;:23:32: error: expected primary-expression before ',' token    23 |      valPro.processValue&lt;Access,X&gt;(x);       |                              ^  How can I refer to Access from the inner class?
In templates, where and why do I have to put typename and template on dependent names? What exactly are dependent names anyway?    I have the following code:  template &lt;typename T, typename Tail&gt; // Tail will be a UnionNode too. struct UnionNode : public Tail {     // ...     template&lt;typename U&gt; struct inUnion {         // Q: where to add typename/template here?         typedef Tail::inUnion&lt;U&gt; dummy;      };     template&lt; &gt; struct inUnion&lt;T&gt; {     }; }; template &lt;typename T&gt; // For the last node Tn. struct UnionNode&lt;T, void&gt; {     // ...     template&lt;typename U&gt; struct inUnion {         char fail[ -2 + (sizeof(U)%2) ]; // Cannot be instantiated for any U     };     template&lt; &gt; struct inUnion&lt;T&gt; {     }; };   The problem I have is in the typedef Tail::inUnion&lt;U&gt; dummy line. I'm fairly certain that inUnion is a dependent name, and VC++ is quite right in choking on it. I also know that I should be able to add template somewhere to tell the compiler that inUnion is a template-id. But where exactly? And should it then assume that inUnion is a class template, i.e. inUnion&lt;U&gt; names a type and not a function?
Rotate touchscreen and disable the touchpad on Yoga 2 Pro in rotated mode On my Lenovo Yoga 2 pro I installed Ubuntu 14.04 32bit and kept the installed Windows 8 on another partition.  In Windows, When you turn it into tablet mode, the keyboard and touchpad turns off so you don't accidently click on it at the back of the "tablet".  In ubuntu 14.04 only the keyboard turns off, but the touchpad stays active. Not even the Fn+F6 combination doesn't turn it off.  So far I can only disable it with  synclient TouchpadOff=1   (and re-enable with 0)  I tried xev to get the keycode for Fn+F6 but pressing this combo generates no output. Turning the monitor to the back neither.  How can I disable the touchpad automatically when I rotate or turn the monitor on the back, and re-enable the Fn+F6 Hotkey?      UPDATE: After some weeks sudo apt-get upgrade Fn+F6 is working now, so there is only the question how to rotate the screen and how to disable the touchpad automatically when rotating the screen. I have noticed that while asking questions and scrolling to the bottom of the page, the right sidebar containing recent questions covers the footer partially. Also, a part of it goes beyond the browser's boundary. It may not be a big problem but it still doesn't look good.    This also happens on the  page I want to show the IP address like below  lo : 127.0.0.1  eth0 : 192.168.5.123 eth1 : 192.172.0.212 wlan0 : 10.1.0.124   I'm able to print all IP address by ifconfig | awk '/inet addr/{print substr($2,6)}'. But it is only printing the IPs. Every system have their own interface names and addresses. So my script has to show their interfaces with respect to IP addresses. Beamer to HTML using make4ht \documentclass{beamer} \usetheme{Madrid} \begin{document} \begin{frame} aaa \end{frame} \begin{frame} bbb \end{frame} \end{document}   The above tex file is to be converted into html. I am using the following command   make4ht filename.tex   However it throws error. The basic question is "Is it possible to convert beamer presentation to html using make4ht?" "Can’t help but" vs. "can help but" Is "can’t help but" considered to be a confused mix of the expressions "can but" and "can’t help"? If not, what is the difference between "can help but" and "can’t help but"? iMac disk partion FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF and fusion drive unlinked What is a 'Closure'? I asked a question about Currying and closures were mentioned. What is a closure? How does it relate to currying? What causes the expansion of space? I accidently ran  sudo chmod 755 -R /   instead of  sudo chmod 755 -R ./   I stopped it after few seconds, but now there is some problems such as  sudo: must be setuid root   How can I revert permissions back? The value of $\lim_{n \to \infty}\int_{0}^{1}nx^ne^{x^2}dx$ Gravitational waves and time Is there an image editor like Windows' Paint for OS X? I tried out several image editors mentioned on  but some of them (like  and ) were very disappointing. These apps were too simple and low level.  What do you suggest for a (preferably free) image editor on OS X?  P.S: I was using  on Linux and also know that it was released for OS X too, but I want to find new good applications. Notation: Why write the differential first? This question is asked in various forms here but the question boils down to:  I know shrinking a database is risky. In this case, I've removed so much data and I'll never use it again.   How can I shrink my database? What files do I shrink?  What should my considerations be while doing this?  Should I do anything after? What if it is a large database? Can I shrink it in smaller increments? How can I comment out a block of text in texmaker? I use texmaker and some time ago I found, by chance, a way to comment many lines at once, but I can't remember it now. Can somebody remind me of that? existence of complex structure in dimension 2 Does an orientable closed 2 manifold always admit a complex structure?﻿  I know that an almost complex doesn' t necessarily give rise to a complex structure(the almost complex structure should be integrable) I am studying 2 manifolds over R, and I wonder if an almost complex structure always exist? This almost structure may be chosen integrable?  I ask because there are certain known results on the different possible geometries in dimension 2.I don' t know exactly how these manifolds (closed and orientable) are classifyied, but I know there are three cases. May be I am confused, and the complex structure is irrelevant to this classification. Some help please! What is the best, easiest, preferably cheapest way to make OS X write to NTFS-formatted drives in Mac OS X? Prove $\gcd(a+b, a-b) = 1$ or $2\,$ if $\,\gcd(a,b) = 1$ I want to show that for $\gcd(a,b) = 1$ $a,b \in Z$   $\gcd(a+b, a-b) = 1$ or $\gcd(a+b, a-b) = 2$ holds.      I think the first step should look something like this:      $d = \gcd(a+b, a-b) = \gcd(2a, a-b)$   From here I tried to proceed with two cases. 1: $a-b$ is even, which leads to $\gcd(a+b, a-b) = 2$ 2: $a-b$ is odd, which leads to $\gcd(a+b, a-b) = 1$  My main problem I think is, that I do not know how I should include $\gcd(a,b) = 1$ in the proof.  Any help is appreciated. Thx in advance. Cherio Woltan A projection satisfying $\| Px \| \leq \|x\|$ for all $x$ is an orthogonal projection How to prove that if $V$ is a finite dimensional inner product space and $W$ a subspace of $V$, if $P$ is projection map ($P^2=P$) having $W$ as its range and is such that $\|Px\| \leq \|x\|$ for all $x \in V$, then $P$ is orthogonal projection of $V$ onto $W$. Prove that $\sum_{k=0}^{m}\frac{\binom{m}{k}}{\binom{n}{k}}=\frac{n+1}{n+1-m}$ Prove that $\sum_{k=0}^{m}\dfrac{\binom{m}{k}}{\binom{n}{k}}=\dfrac{n+1}{n+1-m}$.  We know, n > m. From the right side. we have $\dfrac{n+1}{n+1-m}=\dfrac{1}{1-\dfrac{m}{n+1}}$. since n > m. $0&lt;\dfrac{m}{n+1}&lt;1$. Then $\dfrac{1}{1-\dfrac{m}{n+1}}=1+\dfrac{m}{n+1}+(\dfrac{m}{n+1})^2+...$ I don't know what to do next? Did I choose the right path?