Detect if a type exists in C++
How to detect existence of a class using SFINAE?
Convert a string representation of a hex dump to a byte array using Java? I am looking for a way to convert a long string (from a dump), that represents hex values into a byte array.  I couldn't have phrased it better than the person that posted .  But to keep it original, I'll phrase it my own way: suppose I have a string "00A0BF" that I would like interpreted as the  byte[] {0x00,0xA0,0xBf}   what should I do?  I am a Java novice and ended up using BigInteger and watching out for leading hex zeros. But I think it is ugly and I am sure I am missing something simple. R : constraining coefficients and error variance over multiple subsample regressions Kernel of a substitution map Multi document printing from document library? Is there any one have solution for print multiple documents from Document library? User has option to select multiple documents or single document or inside folder.  I found commercial product "Unbounded Printing Services for SharePoint". But is so expensive. Please share me if you have any thoughts. What are the benefits of playing an alignment other than True Neutral? Can Wolverine survive without oxygen? . Even poisons don't work on him. He seems immortal due to his regeneration powers.  Can he survive without oxygen while his body exists in full working state (I am not talking about skeleton-only Wolverine when his respiratory system is not available)? I'm thinking of following some kind of education in physics online. I have a master degree in Computer Science and have reasonable good knowledge in physics. I would like a program of 1-2 years and I'm more interested in particle physics.   Is there any good online program that offer something similar? What are some CD ripping programs for Ubuntu? Can you list the Pros? What are the Cons? For each program there should be a screenshot, sources to install, and instructions to install and use. Zero to the zero power – is $0^0=1$? Should we MAC-then-encrypt or encrypt-then-MAC? Most of the time, when some data must be encrypted, it must also be protected with a , because encryption protects only against passive attackers. There are some nifty encryption modes which include a MAC (, ...) but let's assume that we are doing old-style crypto, so we have a standalone encryption method (e.g. AES with CBC chaining and PKCS#5 padding) and a standalone MAC (e.g.  with SHA-256). How should we assemble the encryption and the MAC?   MAC-then-Encrypt: Compute the MAC on the cleartext, append it to the data, and then encrypt the whole? (That's what  does) Encrypt-and-MAC: Compute the MAC on the cleartext, encrypt the cleartext, and then append the MAC at the end of the ciphertext? (That's what SSH does) Encrypt-then-MAC: Encrypt the cleartext, then compute the MAC on the ciphertext, and append it to the ciphertext? (In that case, we do not forget to include the initialization vector (IV) and the encryption method identifier into the MACed data.)   The first two options are often called "MAC-then-encrypt" while the third is "encrypt-then-MAC". What are the arguments for or against either? How do I check the series $\sum_{n=2}^{\infty} \frac{(-1)^n }{n+(-1)^n}$ for absolute convergence/conditional convergence ?  How can I solve this problem? How Can I Expand A Tilde ~ As Part Of A Variable? When I open up a bash prompt and type:  $ set -o xtrace $ x='~/someDirectory' + x='~/someDirectory' $ echo $x + echo '~/someDirectory' ~/someDirectory   I was hoping that the 5th line above would have went + echo /home/myUsername/someDirectory.  Is there a way to do this?  In my original Bash script, the variable x is actually being populated from data from an input file, via a loop like this:  while IFS= read line do     params=($line)     echo ${params[0]} done &lt;"./someInputFile.txt"   Still, I'm getting a similar result, with the echo '~/someDirectory' instead of echo /home/myUsername/someDirectory. How to solve apt "package cannot be configured because package is in a different version" errors? Invariant Subspace of Two Linear Involutions I'd love some help with this practice qualifier problem:  If $A$ and $B$ are two linear operators on a finite dimensional complex vector space $V$ such that $A^2=B^2=I$ then show that $V$ has a one or two dimensional subspace invariant under $A$ and $B$.    Thanks! How to convert an instance of std::string to lower case In .NET, which loop runs faster, 'for' or 'foreach'? In C#/VB.NET/.NET, which loop runs faster, for or foreach?  Ever since I read that a for loop works faster than a foreach loop a  I assumed it stood true for all collections, generic collections, all arrays, etc.  I scoured Google and found a few articles, but most of them are inconclusive (read comments on the articles) and open ended.  What would be ideal is to have each scenario listed and the best solution for the same.  For example (just an example of how it should be):   for iterating an array of 1000+ strings - for is better than foreach for iterating over IList (non generic) strings - foreach is better than for   A few references found on the web for the same:               [Edit]  Apart from the readability aspect of it, I am really interested in facts and figures. There are applications where the last mile of performance optimization squeezed do matter. When should I use a List vs a LinkedList This is what happens:  sudo apt-get install vlc Reading package lists... Done Building dependency tree        Reading state information... Done E: Unable to locate package vlc   Please help. I would also like to know when this error occurs, I've seen it before too. What does 'synchronized' mean? Im trying to run the following code as a powershell script,but I cant get it to work. 1st,the following works with one -Include item but I cant seem to get it to work with multiple ones. 2nd, the -Exclude perimeter doesn't seem to work. I still get files from the C:\Windows and C:\Program Files directorys .  $Include = "*.zip","*.rar","*.tar","*.7zip" $exclude = "C:\Windows","C:\Program Files" Get-ChildItem "C:\" -Include $Include -Exclude $Exclude -Recurse -Force -ErrorAction silentlycontinue | Select-Object -ExpandProperty FullName   Note: The purpose of this script is to find all compressed files on the system. I know this is probably really simple but I just cant seem to get it to work.