Using PCL with QT Creator
What is an undefined reference/unresolved external symbol error and how do I fix it?
Once in a while you wish to address a comment to someone in particular, so you type @ and then you pause ... because the username is  or .  Short of using copy-paste to get their username right (which is even more cumbersome on a mobile device), is there another way around this? In a few cases I've noticed that the system will attempt to "promote" a comment to a reply, but I'm not sure if that's very reliable.  Should user names at least start with a normal letter?  Update  The auto-complete feature seems to normalize Zalgo'ish usernames, so typing the letter L will trigger the suggestions as expected; this is of course knowing that the name actually spells "lawrence", which may not always be obvious.  Knowing the way of the symbol ninja would surely help to type Ω using only the elbows as well, but not everyone is blessed with the same keyboard layout.  Suggestion  It would be nice to have a reply feature like this:        When ↳ reply is clicked, it will automatically populate the comment box with @username pre-filled in.   Additional notes  To clarify, I'm not suggesting to put the "reply" on all comments, as proposed , because in most cases the owner of a post is already notified of a new comment; this would strictly be to effect cross-commenter communication. How to get the Input and output in a terminal to a text file? I want to create a text file which will add each command I am going to run on the terminal as a new line entry in the text file. i.e., I need to keep a record of what are the things I'm doing in the terminal. Further if I can keep a record of outputs I'm getting in the terminal, along with the inputs in the terminal, as a text file, it will be much better.   Each time I forget a command I have to search again in the Internet for the command.  Can I can make a file like above? Can I cast a spell while another spell or ability is resolving? My opponent has a  with scads of loyalty. I've got a  and a  on the battlefield.  He activates Sorin's "ultimate" ability, targeting Gideon.     -6: Destroy up to three target creatures and/or other planeswalkers. Return each card put into a graveyard this way to the battlefield under your control.   Is there any way I can use the Spellbomb to prevent my opponent from stealing Gideon after he is sent to my graveyard? This question is here so we can offer users who are looking for information on how to make one or more common or basic redirects in Apache using the htaccess file. All future questions pertaining to finding information that is that is covered by the question should be closed as a duplication of this question. .  Whats the point in this question? The idea while not perfect is catch the most commonly asked questions regarding redirects using the  htaccess on the Apache platform either on  some type of lamp or a live server. The type of answers should be generally those that you could imagine are used by 100,000’s of sites world-wide and are constantly asked here at Pro Webmasters repeatedly over and over in various forms.  A few examples of the type of answers we are looking for:   How can I redirect non-www to www? How can I redirect a sub domain to the main domain? How can I redirect a sub folder from domain to a root or a subdomain?  How can I redirect an old URL to a new URL?   A few examples of the types of answers that we are not looking for:   Answers that do not involve a redirect. Any answers relating to NGinx, IIS or any other non-Apache platform. Answers that involve custom and complex string or query removals.   Resources for Advanced to Complex Mod_Rewrite Rules:      Please note: that this question is still in construction and may need some refining either by myself or a real moderator of Pro Webmasters, if you have any concerns or questions . How can native English speakers read an unknown word correctly? I have learned English for many years, and from the first day I began to learn it I know the dictionary is necessary for the study.  One of the important aspects is that English words, unlike German and Spanish, usually can not be read correctly without phonetics.  But recently, I talked with some native speakers and they told me they can read any word directly and rightly even though they never learned it before.  I just want to know how they can do that -- there is no ordinarily acceptable method to read an English word? What is inertia of a body? Setting print layout to portrait using QGIS 3? I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2. I am currently working to design a flash virtual tour, but I know little about how the photographs are taken.  Ideally I'd like to be able to take a set of 6 shots from a single focal point, and be able to align them seamlessly into a cube form. The other solution is to take a special fisheye image, and stretch it dynamically in flash.  I've seen examples of both as virtual tours, and ones formatted as a rotating cube are more responsive and have a higher image quality. The airbus and Cruden Homes are definitely in the cube format, I'm not entirely certain which format the New York VT uses:        I have a set of questions, the first is the most important, the others may become separate questions if I don't get an answer here:   How are those photos taken? Is there a specific mount that can be used? How long does it take to set up? How much post-processing is necessary on the images? I am looking for a multivariable calculus book that is really physics oriented.  Anyone know of any?  EDIT: My wife is looking to brush up on multivariable at the same time she needs to brush up on the related physics. We will call a matrix positive matrix if all elements in the matrix are positive, and we will denote the largest eigenvalue with $\lambda_{\max}$, what is exist because of the .  Theorem. Let $A$ be a positive square matrix. If any element increases in the matrix then $\lambda_{\max}$ increases.  My questions.    Is there a name for this theorem and can anybody say books or papers what refer to it? How to prove it? Consider the factorization into irreducibles of $6$ in $\mathbb{Z}[\sqrt{-5}]$. We have $6=2 \times 3$ and  $6=(1+\sqrt{-5}) \times (1-\sqrt{-5})$, i.e. $2$ distinct factorizations. And,  $$6^2=3 \times 3\times2\times2$$ $$=(1+\sqrt{-5}) \times (1-\sqrt{-5}) \times (1+\sqrt{-5}) \times (1-\sqrt{-5})$$ $$=(1+\sqrt{-5}) \times (1-\sqrt{-5})\times3\times2.$$ More generally, $6^n$ will have $n+1$ distinct factorizations into irreducibles in $\mathbb{Z}[\sqrt{-5}]$ by a simple combinatorial argument. But, can we construct a ring in which there exists an element that has an infinite number of distinct factorizations into irreducibles? To make life harder, can we construct an extension of $\mathbb{Z}$ in which this happens? I have been thinking about this for a while and have managed to find no foothold.. Any help is appreciated. How to clone ArrayList and also clone its contents? Mathematical notation around the world What are the differences in mathematical notation around the world? I know that in some other countries they write 1,2 meaning 1.2, but what else can be confusing in an academic environment (when people are doing math on a board or on paper). How is acceleration measured if there is change only in the direction of velocity & not magnitude? The formal definition of acceleration is      It is the measure of how fast the velocity changes with respect to time.   Now, when the magnitude of velocity changes, acceleration $$\vec{a} = \frac{d \vec{v}}{dt}$$ and its unit is $m.s^{-2}$ .  But what about the case where the velocity only changes its direction keeping its magnitude constant? The definition can then be      Acceleration is the measure of how fast the velocity changes its direction with respect to time.   But how can I calculate the acceleration then?? What should be the unit then??? Please help. Is 'had have + past participle' a correct grammatical form? Scenario 1: A grimlock hits Alice with a Spiked Bone Club, dealing 5 bludgeoning damage, plus 2 piercing damage. Alice's HP was 12.   Using the optional Massive Damage rules on page 273 of the DMG, does this count as more than half the HP from a single source, or less than half, but twice?  Scenario 2: Assume the same grimlock hits Bob with the same attack, this time rolling 6 bludgeoning damage, plus 3 piercing damage. Bob's Max HP is 8, and he had 1 HP remaining before he was hit.  Using the Instant Death rules on page 197 of the PHB, does the character die, or are the two damage types tracked separately? Does the character have to make a death saving throw for the second part of the damage? How is Selenium RC different from Selenium Web driver and some good pointers for a naive beginner to learn to scripting please? Thanks! Quantum entanglement: does it necessarily imply superluminal information transfer? Boy Born on a Tuesday - is it just a language trick?