Why is the derived class constructor is skipped? I have a code like this  class Base { public:     Base() {}; };  class Derived : public Base { public:     Derived() {cout &lt;&lt; "Derived" &lt;&lt; endl;} };  int main() {     Derived a(); // Only called base constructor     Derived b;   // called derived constructor }   What is the difference between these two calls? My understanding is that base constructor is always called before derived constructor? Why is the derived constructor skipped?  Thanks,
Default constructor with empty brackets Is there any good reason that an empty set of round brackets (parentheses) isn't valid for calling the default constructor in C++?  MyObject  object;  // ok - default ctor MyObject  object(blah); // ok  MyObject  object();  // error   I seem to type "()" automatically everytime. Is there a good reason this isn't allowed?
What does Pirsig mean by "Quality"? $IS \mid JS$ implies that $I\mid J$ where $I$ and $J$ are ideals of a number ring contained in another number ring $S$ Is there a convenient way to import a schema into Oracle 11gR2 using a single new or different tablespace than where the data originated?  As an example, I have exported BLOG_DATA from OLDDB, where all user data is stored in the USERS tablespace.   On NEWDB, I would like to import the BLOG_DATA schema, but store the user objects in the BLOG_DATA tablespace, created specifically for this user.   I have created the BLOG_DATA user, created the BLOG_DATA tablespace and set it as the default tablespace for that user and added an appropriate unlimited quota.  CREATE TABLESPACE blog_data DATAFILE SIZE 1G;  CREATE USER blog_data IDENTIFIED BY secretpassword DEFAULT TABLESPACE blog_data QUOTA UNLIMITED ON blog_data;  GRANT connect,resource TO blog_data   The schema was exported from OLDDB with something like  exp blog_data/secretpassword@OLDDB file=blog_data.dmp    After reading Phil's excellent answer below, I found myself wondering:   Since data has no other place to go than the default tablespace - the only tablespace the user has a quota on - will this effectively force imp to put all user objects in that default tablespace?  imp blog_data/secretpassword@NEWDB file=blog_data.dmp   Would this then place the entire blog_data schema in the blog_data tablespace on NEWDB? Is there any reason why this wouldn't work or that I would run into problems with certain objects etc?  update:  I did a quick test and found this to be the case. Imp places objects in the default tablespace for that user, provided it can't place it in the original tablespace (eg. the tablespace does not exist). Full explanation:   Still, I suppose that using Data Pump like Phil suggests might be the preferred option. Limit FTP access only to the /var/www with vsftpd I am running vsftpd as ftp server on my linux (rasbian), I log in to the machine as a root user.  I would like to be still locked to using only /var/www, how can I configure vsftpd conf to accomplish it? Beautiful table samples I'm interested in learning about some nice-looking table samples. Colors can make a huge difference, and just providing some color to headers, background, or borders can dramatically change presentation. Any samples you're proud to share?  (BTW here's a sample I like, but unfortunately, not TeX...) Seasonal Loan Amortization Why are home networks prefixed with 192.168? Why are home networks prefixed with 192.168 ?  Why those numbers?  For some historical reasons? Can magnets rotate infinitely? There are many videos on youtube in which people arranged magnets in circle and rotated one placing in middle of that circle on a shaft, and the magnet (magnet motor) starts madly and continues its movement. Do they really rotate infinitely? If so, do they from where they get that extra energy to move so fast and infinitely?    EDIT: This question is about real world scenario  UPDATE: I am unable to find that particular video about which i talked about -- I added them to my favourites, but they are all now deleted :( -- there are hundreds of that that kind of videos. Some example videos links How to set date format when manually inserting date on excel, without changing regional settings? In my locale, date is inserted as dd/mm/yyyy or variations of that (including dd-mm-yy). I made an Excel form (in normal Excel file), already formatted to show date as dd/mm/yyyy, but when I typed "05/04/2015" it will be shown as "04/05/2015". I know this can be solved by changing the regional setting to my local setting, but I need to distribute this form to a lot of people with no knowledge of changing regional setting, and assuming no one can teach how to, hence my question :  Is there any way to input "05/04/2015" and be recognized as "5 April 2015", without having to change regional settings ?  Additional note: When I mean "4 May 15" (typed in 4/5/15), Excel will recognize this as "5 April 15" because Excel takes input as "mm/dd/yy" format. I need to change the default behavior of Excel to take as "dd/mm/yyyy" as this is the way the users will input.  If possible, the setting should also included/embedded on the file to allow end-users use the form without even changing setting.  I'm not familiar with macros and VBA, but willing to try those :)  EDIT : this is related to my question :   but I don't need to change the whole formula bar, as long as Excel recognize that I'm typing in dd/mm/yy format. How do I change the GRUB boot order? How do you find the modular inverse of $5\pmod{\!11}$ The energy of a moving object is $E = mv^2\;.$ That is it increases with velocity squared.  I walk at say 3 miles per hour, or lets round that down to 1 meter per second for a slow walk. I weigh less than $100~\mathrm{kg}\;,$ but lets just round that up to $100~\mathrm{ kg}$ for convenience (it is just after Christmas).  So when I walk along the pavement, I have $100~\mathrm{kg\; m^2 s^{-2}}$, 100 joules of kinetic energy.  Now I get on a passenger jet, which is cruising at around 500 knots, call that 250 meters per second.  In my seat I have $100\times 250^2 = 6250000$ joules of kinetic energy. But when I walk down the aisle I have $100\times 251^2 = 6300100$ joules of kinetic energy. The difference between these is: 50100 joules.  It feels the same to me, walking down the pavement as walking down the aisle of the plane. I didn't have to make some huge effort to get up to speed on the plane, yet I needed 500 times the energy to do it.  How is this possible, and where did the energy come from? bash: warning: shell level (1000) too high, resetting to 1 Want to fill line with repeating string Similar to the \dotfill command, but with your own text, rather than dots.  If the string was: kitty!  The entire line would look like the following: kitty!kitty!kitty!kitty!kitty!kitty!kitty!kitty!kitty!  Is there any way to do this? How to create a progress bar? There are no compact minimal surfaces How does two-weapon fighting work? I'm quite confused about attacking with two weapons in both hands and wondering what is required to be able to do to (in Pathfinder).  1. Base Attack Bonus Looking at the base attack bonus tables for different classes (e.g. the ) it seems like up to +5 you get only one attack per full action but starting from base-attack-bonus of +6 you get a second attack with +1.  2. Feats There is a feat . The existence of the feat sounds like you could not do two-weapon-fighting without it. However, in the description of "normal" it says:     If you wield a second weapon in your off hand, you can get one extra attack per round with that weapon. When fighting in this way you suffer a –6 penalty with your regular attack or attacks with your primary hand and a –10 penalty to the attack with your off hand. If your off-hand weapon is light, the penalties are reduced by 2 each.   3. Core Rulebook Chapter about combat If I understand the  it says that you need a full-round action do attack with both weapons in two hands.  So how do these things interact? Can I only attack with my off-hand weapon if my base-attack-bonus is high enough that I get second one with +1?  If not, how does the "multiple attacks from high base-attack-bonus" interact with dual-wielding? Assuming I reached a state of base-attack-bonus with +11/+6/+1 and have a full-round action to attack. Does that mean I can either attack with my primary weapon three times or use the primary weapon and off-hand weapon to attack only twice? Why would I then ever choose dual-wielding? Or can I attack three times with both weapons (leading to a total of 6 attacks with heavy malus) Or would I get 3 attacks with the primary weapon + 1 attack with the off-hand weapon? If so, what attack bonus do I have to use for each of the attacks? @online bibliography biblatex Is Cursed Child canon to the original story? From what I am hearing the stage-play called The Cursed Child is based on the characters from the Harry Potter series. It is set 19 years from the end of Deathly Hallows (i.e. When Harry's children are starting their time at Hogwarts).   I have also seen the J.K. Rowling has had at least some involvement and been on the set and a part of rehearsals, etc.   My question is has there been a statement given relating to the canon of the stage play to original series? If so, would any conflicting information be considered a retcon?  Related:  - but not dupe because this asking about in-universe information. There are five boxes consisting of several identical coins. There are five boxes consisting of several identical coins. The first box contains 4 coins, the second box contains 9 coins, the third box contains 7 coins, the fourth box contains 10 coins, and the fifth box contains 3 coins. Some coins are taken from the boxes such that at least a coin taken from each box. In how many ways in taking the coins, such that the numbers of the coins taken are 12?  My attempt was solving it using repetition combination of which, there are only seven coins remaining considering that at least a coin taken from each box. By using the repetition combination, i.e. taking 7 from 9 (five boxes and four borders), resulting in 36 ways. However, there is no 36 ways in the choices.