Static member undefined reference c++ without header file
Undefined reference to static class member
Could the Infinity Gauntlet be used to make two people fall in love with each other? I am wondering if there is anything in Marvel comic book canon or in the MCU that says that the Infinity Gauntlet has the power to make someone fall in love with the person wearing the Infinity Gauntlet, or that the wearer of the Infinity Gauntlet can use the Infinity Gauntlet to make two strangers fall in love with each other? Perhaps the combined power of the Mind Stone and the Soul Stone would make two people fall in love. Why was M87 targeted for the Event Horizon Telescope instead of Sagittarius A*? The first image of a black hole has been released today, April 10th, 2019. The team targeted .  Why didn't the team target  at the center of our own galaxy? Intuitively, it would seem to be a better target as it is closer to us. Is password confirmation necessary on a Change Password dialog? On one hand there is no need to ask for password confirmation because it is annoying. If I made a mistake when confirming my password I'll need retype my very complex password again. There is also a button that can show/hide the password so I don't need retype it in order to confirm it.   However, some users don't use the password show/hide button and the 'forgotten password' option will be pain for them.  Twitter removed the password confirmation from registration but left the dual confirmation in place for changing password. Is this right approach? What should I do when I have lenses with different filter thread sizes? Can an integer of the form $4n+3$ written as a sum of two squares? Is there a difference between "==" and "is"? If $X_1, ..., X_n$ are independent identically-distributed random variables, what can be said about the distribution of $\min(X_1, ..., X_n)$ in general? Root filling up although it should have some space This has been perplexing me for some time. I'm on Ubuntu 11.04. My root partition is filling up and I can't figure out what's causing it. Even stranger, when I run df -h, this is the output:  Filesystem            Size  Used Avail Use% Mounted on /dev/sda2             9.2G  8.8G     0 100% /   As you see, there should be about 400 MB free, but Avail shows 0. What could be causing this? I've even uninstalled some programs to free the space and it fills up again. Suggestions on how to find out which, if any, files are filling up the space are also welcome. "Geometric" or "Geometrical"? I have read the excellent answers to  - my question is specifically about usage.   Is there a best practice for deciding between the variants geometric and geometrical in writing? A  shows that geometrical was more popular until about 1965, when they switched. What grammatical rules, if any, would be relevant here? $Path hijacked by PacletManager? I think my son was trying to guess the passcode! What do I do?  I can't wait 42 years! How to store and preserve film negatives and slides? I bought 35mm dedicated film scanner (Nikon CoolScan III) and I'm planning to digitize old negatives and slides I found at home.  How should I store and preserve these slides and films after I cut them and scan? How to choose best negative pages/sleeves, binders etc. and what to avoid? How to get the center line between two linestrings Where is the track of a ship when it is shipping always in the center of the   between the coasts of Great Britain and France?   I started with 2 linestrings and I created a lot of points on the linestring with a . After that I created a distance matrix with Raster/Analysis/Proximity in QGIS. Finally I created an aspect raster from the output raster.     Is the red line really the "center line" between these two linestrings?  Is there a more efficient way to do this? I'd really like to learn how to play pen-and-paper RPGs.  I know that it takes a few players to actually sit down and play, but I'm not at all sure where to find more gamers.  How do I find existing groups to join? Or, are there any resources online that may help me find existing RPG groups or players? Where are the NetworkManager logs? A previous poster on the regular forums (  ) said /var/log/daemon.log, but I don't seem to have such a file. Do I need to enable logging? Compile nested Sums How do you do Impersonation in .NET? Is there a simple out of the box way to impersonate a user in .NET?  So far I've been using  for all my impersonation requirements.  Is there a better way to do it by using .NET Framework?  I have a user credential set, (username, password, domain name) which represents the identity I need to impersonate. For f continuous on $[0,1]$, show that there exist points $\alpha_k$ such that $\sum \limits_{k=1}^n \frac{1}{f'(\alpha_k)} = n $ Install Java JDK and JRE on Debian 8 I installed Debian 8, I would like to install Java JRE and JDK. I use  and it works.  But, I am afraid because it's a script hosted in a repository. I would like to understand why it doesn't work when I put the extract of  in /usr/java/jre1.8.0_73 directory as . I added the path variable with PATH=/usr/local/jdk1.8.0/bin:$PATH export PATH as explained in  but it doesn't work.  Even if I try to install OpenJDK, the package isn't found. I don't understand why it's so complicated to install Java on Debian; it is very simple on Ubuntu. I would like someone give me step-by-step instructions to install it. I am looking for a word that describes both of these activities, however the word coding does not seem to be suitable.   Likewise with encryption and decryption, cryption does not work well.