Returning const values to leverage move semantics vs preventing stuff like (a+b)=c
Isn't the const modifier here unnecessary?
how to convert NTFS to ext4 in windows? LaTeX multi-character subscript Shortest path from points in one layer to points in another layer via roads in QGIS I'm looking for a way to calculate the shortest path from addresses to subway stations via a network of roads.  I have the , however, the addresses and subway stations are point layers that do not overlap with vertices in the roads layer.  In QGIS, is there a way to calculate the shortest distance from the address/subway station points to the roads, create vertices at those locations, then calculate the shortest distance via the roads network?   black squares - addresses white circles - subway stops gray lines - roads tikz: Distribute evenly and randomly circles I want to fill a part of a picture with more or less evenly and randomly distributed circles which should not overlap. It would be okay if circles are only partly inside the shape.  The density should be like what you see on this page  with values 80-100. (But I do not need so many circles, 30 should be enough, I could repeat the pattern).   I cannot use a grid and "wobble" the circles a bit: The circles are too large and it simply does not look randomly.   Currently I am thinking about a random attempt: Get some random point, measure its distance to existing circles, either paint or throw the point away. Try 100 times and hope that you get the right number of circles (and that it does not take too long). But perhaps someone has a better idea.   The example draws the circles simply manually:  \documentclass{article} \usepackage{tikz} \usetikzlibrary{backgrounds} \begin{document}   \begin{tikzpicture}[framed,gridded,radius=0.5cm]  \draw[red](0,0) rectangle (5,5);   \draw (1,1) circle;   \draw (2.3,1.1) circle ;   \draw (4.5,0.8) circle ;   \draw (5.1,1.8) circle ;   \draw (0.4,3.3) circle ;   \draw (2.1,2.8) circle ;   \draw (3.8,3.5) circle ;   \draw (4.8,4.2) circle ;   \draw (0.8,4.9) circle ;   \draw (2.1,4.1) circle ;   \draw (3.8,2.0) circle ;   \draw (3.5,0.6) circle ;   \draw (3.0,5.0) circle ;      \draw (4.1,5.1) circle ;             \draw (0.9,2.1) circle ;  \end{tikzpicture}  \end{document} Copyright of a set of colors? I often see color combinations on webpages, images, posters, products etc. that harmonize really well. Am I allowed to use those colors in my own design?   This is solely about the colors. I will not use images, logos or shapes from that source, and my content is not related to the original color source. I am also far from any commercial aspect here. What is the best way to explain how to choose between "its" and "it's"? Open more than one instance of Windows 10 settings How can I open more than one instance of the Windows settings?  It wasn't a problem with the old style, but with the new one I can't seem to open multiple settings simultaneously and side by side.  Example of the new settings window: How do I call legacy PHP files? I am unable to call PHP files inside the Drupal directory. My task is maintaining staff's old pages on the new platform. With pages written on clear HTML, there is no problem: I place files in a folder I created (domain.org/sites/default/files/share/staff_folder).  In sites/default/files/.htaccess I added DirectoryIndex share and now the link to the domain.org/sites/default/files/share/staff_folder/index.html can be used. When I import pages written in PHP, e.g. calling domain.org/sites/default/files/share/staff2_folder/index.php, I get a 403 error:     Forbidden      You don't have permission to access /sites/default/files/share/staff2_folder/index.php on this server.   While /sites/default/files/share/staff2_folder/index.html still works. How much movement does it take to stand up from prone when my speed is modified? Suppose my speed is normally 30 feet. I get hit with a Slow spell, reducing my speed to 15 feet, and then I get knocked prone. How many feet of movement do I need to spend in order to stand back up from prone? How many feet of movement do I have left over once I've stood up?  What if I am also hit with a Ray of Frost spell while slowed, reducing my speed to 5 feet for 1 round? Am I able to stand up at all? Why does \cal{M}_n give “M>”? Why does \cal{M}_n give “M>” in parts of my LaTeX file and works correctly in other parts? What application launchers are available for Ubuntu? Kill Command in linux Weak solutions to the Neumann's problem (Evans PDE) Let $U$ be connected. A function $u \in H^1(U)$ is a weak solution   of Neumann's problem   \begin{equation} (*)\qquad\left\{ \begin{array}{rl} -\Delta = f &amp; \text{in } U \\ \frac{\partial u}{\partial \nu} = 0 &amp; \text{on } \partial U \end{array} \right. \end{equation}   if   $$ \int_U Du \cdot Dv \; dx = \int_Ufv \; dx $$   for all $v \in H^1(U)$. Let $f\in L^2(U)$. Prove $(*)$ has a weak solution   if and only if   $$ \int_U f \; dx =0. $$   For the only if part I set $v=1$. However I do not see where to start the if part. I was thinking of the Lax-Milgram theorem. That's where I'm now. Updating a chart dynamically in Numbers Background: I've been having some sleep issues so I have started tracking my sleep habits along with some other data but so far, they are just entries in Evernote and as such it is not possible to see any patterns. Obviously I need a spreadsheet app with charting capabilities (doh!). I've been using a great iPhone app called  for data collection for sleep times and then enter those into Evernote.  I have the iWork set so I have been looking at Numbers and going through some tutorials but I still can't tell if it will do what I want. Given that my data set will increase daily, I'd like to be able to "page through" a chart/data set, so it shows say the last 30 data entries. With all the tutorials I have seen, the charts are of fixed size and adding more data to a linked table just causes the chart to cram more stuff in.  Can Numbers do this sort of "paging" of data? I would like to have this sort of "on the fly" charting rather than having to explicitly build a chart each time I want to visualize the data.   (sorry the question is rather garbled: I don't know really anything about using a spreadsheet type app) Prove that a group is infinite and nonabelian. I'm trying to solve a question of Hungerford's Algebra:     Show that the group defined by generators $a,b$ and relations   $a^2=b^3=e$ is infinite and nonabelian.   I guess a good approach would be to find an infinite and nonabelian group with two generators satisfying the same conditions and let Van Dyck do all the work. I've been thinking about the group of permutations $S_{\mathbb N}$, some groups of matrices, but I couldn't get it. Could anyone give me a hint? Thanks in advance! Puzzling Enumerable.Cast InvalidCastException The following throws an InvalidCastException.  IEnumerable&lt;int&gt; list = new List&lt;int&gt;() { 1 }; IEnumerable&lt;long&gt; castedList = list.Cast&lt;long&gt;(); Console.WriteLine(castedList.First());   Why?  I'm using Visual Studio 2008 SP1. I used to use a lot ctrl+alt+numpad to move windows, how can I use this feature on ubuntu 18 like it was default before?  Thank you in advance Show $\,p\mid 9^q -1 \implies q\mid p-1$ for odd primes $p$ and $q$ If $p$ and $q$ are odd primes show that $$p|(9^q -1) \implies q|(p-1).$$ ....  I am having difficulty to prove this.  Yes that was the question I have misunderstood between 9 and q!!! Journals selection - alternative criteria to impact factor While trying to select the journals I can submit my present work and future work, I realize the time between the date the authors send the article to the journal and when the revised article is submitted. Usually this is something between 6 months and more than 12 months.  Althought I am focusing on the Impact Factor (IF) to select journals, I think that 12 months to have a feedback that might include "add more variables analysis","this article will be more valuable if you test also model x,y and z", can have a huge impact on you work. It will make you stop what you are currently doing and possible spend up to 2 months making the changes. This might make a big mess on your work if you have deadlines to respect, however this happens to everyone in academia.  My question is, besides the IF journal based selection, how can we select a journal with enought quality with lower IF? What alternative criteria should one use to select the journal? Should we choose newly created Journals? Why is looping over find's output bad practice? This question is inspired by    I see these constructs  for file in `find . -type f -name ...`; do smth with ${file}; done   and  for dir in $(find . -type d -name ...); do smth with ${dir}; done   being used here almost on a daily basis even if some people take the time to comment on those posts explaining why this kind of stuff should be avoided... Seeing the number of such posts (and the fact that sometimes those comments are simply ignored) I thought I might as well ask a question:  Why is looping over find's output bad practice and what's the proper way to run one or more commands for each file name/path returned by find ?