When is forward declaration not enough? The #include problem  class widget { };  class fubar : public widget { // 1      void value_parameter(widget); // 2         void ref_parameter(widget &amp;); // 3     void ptr_parameter(widget *); // 4      virtual void value_parameter(widget); // 5     virtual void ref_parameter(widget &amp;); // 6     virtual void ptr_parameter(widget *); // 7      widget value_return(); // 8     widget &amp; ref_return(); // 9     widget * ptr_return(); // 10      widget instance_value_member; // 11     widget &amp; instance_ref_member; // 12     widget * instance_ptr_member; // 13      static widget static_value_member; // 14     static widget &amp; static_ref_member; // 15     static widget * static_ptr_member; // 16 };   Which of those lines require a has include?  (#include "widget.hpp")
When can I use a forward declaration? I am looking for the definition of when I am allowed to do forward declaration of a class in another class's header file:  Am I allowed to do it for a base class, for a class held as a member, for a class passed to member function by reference, etc. ?
Strip whitespace from jsp output How can I strip out extra whitespace from jsp pages' output?  Is there a switch I can flip on my web.xml?  Is there a Tomcat specific setting? Where is Jon going? I'm doing a masters course at a different university than I did my undergrad (both in maths). I did well in my undergrad but now I'm finding it very difficult. The shock of the change is hard to cope with.  I'm not just finding it very difficult, but I get zero feedback: we don't have any tests and I was not able to make friends so I don't know how others are finding it. I'm starting to think that I might be an idiot.   How can I build some confidence in my abilities at the same time as I rush and struggle to keep up with the massive rate of new material I need to learn? How might I get myself some reassurance that I can actually pass, or stop worrying about this so much? (I feel terribly guilty using so much money from my family to be here) It's possible that I don't really have a chance at all but knowing that would be fine. Let $X$ be a normed vector space.   Show that if a subsequence of a Cauchy sequence converges, then the whole sequence converges. Use the part 1 to show that $S = \{x\in X : \|x\| = 1\}$ is complete if and only if $X$ is Banach.     I have found the first part in a book, but I do not how to prove part 2. Thanx regards Do iOS app visits count to your consecutive visits Given two input layers  The clip layer - an arbitrary layer (though in my case it's a float 1 band geotiff) The mask layer - a paletted raster in which every pixel is either NO DATA or a single &quot;color&quot; value, same for every pixel.  I want to create an output raster whose overall extent matches the extent of the mask layer and each pixel is either NO DATA if the corresponding pixel of the mask layer is NO DATA or the value of the corresponding pixel from the clip layer if the corresponding pixel of the mask layer is not NO DATA. I know I can mask the clip layer with a polygon, but the mask layer is a raster. Polygonizing the raster layer is possible in principle, but would result in a polygon with a lot of very short edges. Is there a direct way to do this in QGIS? I suppose there's probably a path that involves creating a new layer and using the raster calculator, but I'm hoping there's something more direct. Further complicating the matter is that the two rasters might not have the same resolution and origin. I believe this is equivalent to  in ArcMap. Incorrect plot using pgfplots (trigonometric functions like cos, sin and tan) I'm looking for a time and memory efficient solution to calculate a  in C. I need to avoid dividing because I'm on a PIC 16 which has no dedicated division unit.  At the moment, I just store all values in a  and simply store and update the sum each time a new value arrives. This is really efficient, but unfortunately uses most of my available memory... When and where do I have the highest chance of seeing auroras? I'm wondering what time of year is best, and what locations might be best, for catching the aurora.  I'm currently thinking of February up at Sweden's ice hotel, but since the whole point of the trip is so that my wife can see the Aurora, I want to pick a location that affords the best chances to see one.  Edit: Just adding a link so you can see realtime aurora activity in the northern hemisphere    I know this is anecdotal, but I ended up going to Iceland in late february during the new moon and saw the aurora 3 out of 6 nights I was there.  There was activity every single night but the biggest problem was weather.  It was cloudy almost every single night. I'm looking for a 90s (or early 2000s) scifi (mini)series where a boy and old man chase a black guy in metal suit. I think they were going through different dimensions. I remember part of it, but I don't think I ever saw how it ended. I remember my friend telling me there was a twist at the end. I think they were trying to find something and he was always ahead of them.. How to reverse name and first name? What is the maximum length of a URL in different browsers? What is the maximum length of a URL in different browsers? Does it differ among browsers? Is a maximum URL length part of the HTTP specification? Need Help Fixing Grub after Installing Ubuntu 13.04 x64 Alongside Windows 8 on a Lenovo IdeaPad Y400 with UEFI I have a Lenovo IdeaPad Y400 that came pre-installed with Windows 8. I would like to run Ubuntu alongside it in a dual-boot configuration. I've spent the past week fiddling around, re-installing both Windows and Linux in various configurations, and I've come awfully close to success, but seem to have hit a snag with Grub.  For my most recent attempt, I took the following steps:   Disabled Secure Boot Re-imaged Windows 8 from a hidden recovery partition, effectively restoring the machine to factory state Activated an option called Legacy Support in the BIOS (or is it UEFI now?) Booted Ubuntu 13.04 x64 from a USB stick, chose "install alongside Windows" and accepted all default options After a restart, found that I could boot Ubuntu, but could not boot Windows Once into Ubuntu, I ran Boot Repair with recommended settings and accepted all defaults. When Boot Repair finished, I was presented with the following message:      The boot files of [The OS now in use - Ubuntu 13.04] are far from the   start of the disk. Your BIOS may not detect them. You may want to   retry after creating a /boot partition (EXT4, >200MB, start of the   disk). This can be performed via tools such as gParted. Then select   this partition via the [Separate /boot partition:] option of [Boot   Repair]. ()    I followed the instructions at the url in the message, creating a 1GB EXT 4 partition near the start of the drive  when I tried to run Boot Repair again, the "Separate /boot partition" option on the "Grub Location" tab was disabled.  The new partition is /dev/sda11 and has the label GRUB. On restart, I get the following error message:      error: file '/boot/grub/i386-pc/normal.mod' not found.    grub rescue>    However, if I manually choose the boot partition by hitting F12, I can boot into Windows no problems. Selecting Ubuntu from the boot device menu gives me a Grub menu with the following options:      Ubuntu      Advanced options for Ubuntu       Windows UEFI recovery bootmgfw.efi      Windows Boot UEFI recovery       Windows UEFI recovery LrsBootmgr.efi      Windows Boot UEFI recovery bkpbootx64.efi       Windows Recovery Environment (loader) (on /dev/sda3)       Windows 8 (loader) (on /dev/sda5) System setup    Selecting Ubuntu from this menu allows me to get to my Ubuntu desktop. I haven't tried the other options yet for fear of losing the progress that I've made.   So it looks like I have successfully dual-booted the machine, but that Grub is broken for some reason or another.   My current partition scheme can be seen at:   Thanks in advance - Jonathan What is the best way to add options to a select from a JavaScript object with jQuery? no border around hyperlinks with hyperref I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents: I have a list with a people column called AssignedTo.  I'm making a rest call:  .../_api/web/Lists/GetByTitle('listname')/Items?$expand=AssignedTo&amp;$select=*,AssignedTo/Title   Which is successfully returning the name of the person the item was assigned to. I'm trying to get other user information like email or their user id.  Most tutorials online show how to expand ID and Title (Name) and  I found a list of these properties that can be expanded:   ID FirstName LastName Title Department SipAddress   And those all work. But I can't find the email and or the login ID. I've tried $select=AssignedTo/LoginName and several other variations on that, but they all return that the field is not valid. I was hoping $select=AssignedTo/* would expand all the fields, but that doesn't rework either.  Anyone know if the above are the only fields that can be expanded off a people column? Show that if $|f(z)| \leq M |z|^n$ then $f$ is a polynomial max degree n I can't prove this statement, can anybody show me how to prove it?    $$f:\mathbb{C}\rightarrow \mathbb{C} \in \mathcal{O}(\mathbb{C}), \exists n\in \mathbb{N}, R &gt;0 , M&gt;0 : |f(z)| \le M|z|^{n} \ \ \forall |z|&gt;R \Rightarrow \deg(f)\le n $$  To show is that if there exists such an $M$, that then $f$ is a polynomial of max degree $n$. I started like this:   $$f(z) = \sum_{n=0}^{\infty} a_n (z-z_0)^n$$ So if I put this into the inequality: $$|f(z)| = \left| \sum_{n=0}^{\infty} a_n (z-z_0)^n \right| \le M |z|^n .$$ I am travelling to Budapest and therefore have a Schengen Visa. I hold an Indian passport and a valid US visa. I'm travelling from Chicago-Heathrow-Budapest and returning by Budapest-Dublin-Chicago.  Would I need a transit visa for UK/Ireland?  UPDATE  Hoping this will help someone someday.   I was not allowed to board my return flight (BUD-DUB-ORD) because I do not hold an overnight Irish Transit Visa. They said I could have transited happily if the connecting flight was in the same day, but because I would have to originally land at 10 PM and catch the connecting flight next morning at 10 AM, I needed a transit visa. Well, I thought it was BS, but couldn't help comply with the rules. I booked another last minute ticket and flew via Warsaw via LOT. Migrate to *any* site?