Is this code correct? int *set_new (int choice) {    int *new_choice {new int};    *new_choice = choice;    return new_choice; }  Should I delete *new_choice after the value is returned, because *new_choice is on the memory heap? int *set_new (int choice) {    int *new_choice {new int};    *new_choice = choice;    return new_choice;    delete new_choice; }  Or, do I need to delete it where the function is finished calling? if not deleted, will it cause a memory leak? I learned on a website if you use dynamic memory (new) immediately after that delete (delete) so there is no memory leak. The function is called in main: int main () {  int *b {new_choice (23)};  printf (&quot;% d&quot;, *b);  delete b; }
I think we all understand the necessity of delete when reassigning a dynamically-allocated pointer in order to prevent memory leaks. However, I'm curious, to what extent does the C++ mandate the usage of delete? For example, take the following program  int main() {      int* arr = new int[5];      return 0; }   While for all intents and purposes no leak occurs here (since your program is ending and the OS will clean up all memory once it returns), but does the standard still require -- or recommend -- the usage of delete[] in this case? If not, would there be any other reason why you would delete[] here?
Does using an extender actually change the aperture of the lens? I just bought a Canon 2X extender and I always believed that it would only result in 2 stops' loss of light and not change the aperture.    However, when I tested this extender on a Canon 135mm f/2 lens, the maximum aperture I could set went down to F/4.  So it kind of confused me, because if I step down the aperture to f/5.6, is it actually setting the aperture to f/5.6 or f/2.8 (i.e., 1 stop below f/2)? I am trying to define an alternative \item command that would allow me to use a different color for some of the items. My code has the following form:  \documentclass{article} \usepackage{color}  \definecolor{gray}{rgb}{0.7,0.7,0.7} \newcommand{\grayitem}[1]{{\color{gray} \item #1}}  \begin{document}  \begin{enumerate} \item First item. \grayitem Second item. \item Third item. \end{enumerate}  \end{document}   I was hoping that  \grayitem Second item.   would produce the same result as  {\color{gray} \item Second item.}   but for some reason, these are not equivalent. They produce the following results, respectively:  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;   Why are these two lines of code not equivalent? What am I doing wrong and how can I change the definition of \grayitem to produce the second result?  I have also tried removing a pair of braces, like this  \newcommand{\grayitem}[1]{\color{gray} \item #1}   but then the third item becomes gray as well.  The solution should also work for multi-paragraph items. I have read the explanation for this in several textbooks, but I am struggling to understand it via Archimedes' principle. If someone can clarify with a diagram or something so I can understand or a clear equation explanation that would be great. I recently moved to Linux, and I am in love with the experience. Opinions apart, I am having problems when running sudo dpkg --configure -a  My computer stops processing the command here:  You may know Adobe Flash Player is no longer supported, and I believe that could be why the command is unable to load pepperflashplugin-nonfree. I have tried fixing the problem by checking older posts here, but none of them was able to fix this problem. How to remove the association between two Gmail accounts? I want to remove that other account. Both of them are Gmail accounts. How could I do? Why we won't extract heat from air temperature? Alignment of the titles in a ToC and \Roman{section} There is a problem with the alignment of the numbering of the ToC: When we use   \renewcommand{\thesection}{\Roman{section}}   the numbers encroach on the titles. When the command is commented out, the numbers are all aligned [from the first number on the left] but the titles do not begin at the same position.  What I want is to use \Roman{section} but with the numbers being displaced after V (or 9 in arabic) so that the first letters of the  titles are all aligned !  An illustration:  %\RequirePackage{fix-cm} \documentclass[a4paper, 11pt, twoside]{article}  \renewcommand{\thesection}{\Roman{section}}  \begin{document}   \tableofcontents \normalfont %\cleardoublepage  \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY} \section{QWERTY}  \end{document} Python: access class property from string Show that $e^{-\beta} = \frac{1}{\sqrt{\pi}} \int_{0}^{\infty} \frac{e^{-u}}{\sqrt{u}} e^{-\beta^2 / 4u} du$. Show that $e^{-\beta} = \frac{1}{\sqrt{\pi}} \int_{0}^{\infty} \frac{e^{-u}}{\sqrt{u}} e^{-\beta^2 / 4u} du$.  I'm not really sure of how I should proceed to show this, and it's pretty un-intuitive as well.  I've managed to manipulate the RHS into  $$\frac{e^{4\beta}}{\sqrt{\pi}} \int_0^\infty \frac{1}{\sqrt{u}} e^{-(\beta+2u)^2/4u} du$$ which now vaguely resembles a Gaussian. However, substituting $v = \beta + 2u$ in in order to to get something like $e^{-x^2}$ doesn't particularly help. I got $$ \frac{e^{4\beta}}{\sqrt{2\pi}} \int_0^\infty \frac{1}{\sqrt{v - \beta}} e^{-v^2/2(v-\beta)} dv. $$  I'm really unsure of how I should proceed; any help would be appreciated. I have a large number of zip files that were compressed using the zip command. I would like to recompress them with the -9 flag to improve the compression ratio. Does anyone know if that can be done without manually decompressing and then compressing.  PS. I need to keep them as zip files since they are served to windows users( and as such have white spaces in their names) Boot error > no such device: grub rescue After an installation of Ubuntu 12.04, erasing an old partition with Ubuntu 10.10, I can't get grub to load. I can't access my Windows 7 partition either  I get the message:  &gt; error: no such device: 58ABF29C...   grub rescue&gt;   I suppose my master boot record got erased/corrupted. How can I check and fix this? Play Framework (2.1.3) doesn't run any tests I have spent a whole day trying to solve the following problem. Please help if you know how to do this.  I am using natbib (\usepackage[sort&amp;compress,square,comma]{natbib}), and my current citation style looks like [1-4], [5, 8-9].  What is the easiest way to change the citation style to [1]-[4] and [5],[8]-[9]? If $$Y=\sum_{i=1}^{N}X_i^2$$ where $X_i \sim \mathcal{N}(0,\sigma^2)$, i.e. all $X_i$ are i.i.d. normal random variables of zero mean with same variances, then $$Y \sim \Gamma\left(\frac{N}{2},2\sigma^2\right).$$  I know the chi-squared distribution is a special case of the gamma distribution, but could not derive the chi-squared distribution for random variable $Y$. Any help, please? What's your recommendation on drive partitioning schemes for a desktop and home server? What partitioning scheme do you recommend for a desktop? I've always created three or four primary partitions -- root, swap, home, and sometimes a separate boot partition. Ubuntu's default install offers LVMs. I've never had to add additional drives or space, so it never seemed like a big deal. Whenever I do a fresh install, though, I always think there might be a better way. How can I limit ssh *remote* port forwarding? I need to limit which ports can be remotely 'ssh -R' forwarded by an user.  I know about permitopen option on authorized_keys, but as it says on man page it only limits local 'ssh -L' port forwarding  As discussed  a user would get the same with netcat or similar, but in this case user has no shell access  I also found  that talks about using selinux or LD_PRELOAD, but I never configured selinux before and can't find info on how to do that with LD_PRELOAD.  maybe someone have made a patch for openssh to implement that?  EDIT: I've found  so I guess it's not yet implemented Schengen Visa Refusal: Justification for the purpose and conditions of the intended stay was not provided Markdown code snippets don't allow trailing spaces I am having some issues with the hyperref package. I would like to create a Introduction chapter without a number so I use \chapter*{Introduction} and \addcontentsline{toc}{chapter}{Introduction} because I want it in the table of contents (see example).  But then the link in my PDF viewer gets it wrong and also the automatically created header is no longer correct (see picture). The table of contents shows the right page number (p.1) but the link is also wrong.   What is my mistake here?  \documentclass{scrbook}  \usepackage{hyperref} \usepackage{blindtext} \usepackage{glossaries}   \makeglossaries  \newacronym{eg}{e.g.}{% for example }   \begin{document}   \frontmatter  % abstract before the table of contents \chapter*{Abstract} \addcontentsline{toc}{chapter}{Abstract} \blindtext  \tableofcontents  % chapter with acronyms \cleardoublepage \phantomsection  \printglossary[type=\acronymtype] \addcontentsline{toc}{chapter}{Glossary}  \cleardoublepage \mainmatter   \phantomsection % \chapter{Introduction} % with this everything is correct but I don't want the number \chapter*{Introduction} \addcontentsline{toc}{chapter}{Introduction}  \blindtext  \pagebreak  \blindtext  % first chapter \chapter{Chapter1}  \gls{eg} \blindtext  \pagebreak  \blindtext   \end{document} I'm looking for a way of saying “having amorous affairs”. Ideally it should indicate a married man fooling around with younger women, and the expression should be informal, humorous, in low register but yet not rude.