I remember a quote from a while ago that went somewhere along the line x is saying ´fuck you´ to a person but making them feel flattered   It's a quality that makes somebody polite, manipulative and tactful.
Is there a specific term for a statement that uses words such that their precise meaning conveys a subtext contrary to the colloquial meaning?  For example, the joke in Men in Black:     Gentlemen, congratulations. You're everything we've come to expect   from years of government training.   where the precise use of the words conveys a sarcastic meaning (ie that the candidates are inept because that's what he's come to expect from government training).  I was going to use "irony" to describe this but then realized this is basically the opposite of irony - the use of words to convey their literal intention, when a nonliteral intention was expected.
Do you have to pass delete the same pointer that was returned by new, or can you pass it a pointer to one of the classes base types?  For example:  class Base { public:     virtual ~Base();     ... };  class IFoo { public:     virtual ~IFoo() {}     virtual void DoSomething() = 0; };  class Bar : public Base, public IFoo { public:     virtual ~Bar();     void DoSomething();     ... };  Bar * pBar = new Bar; IFoo * pFoo = pBar; delete pFoo;   Of course this is greatly simplified.  What I really want to do is create a container full of boost::shared_ptr and pass it to some code that will remove it from the container when it is finished. This code will know nothing of the implementation of Bar or Base, and will rely on the implied delete operator in the shared_ptr destructor to do the right thing.  Can this possibly work? My intuition says no, since the pointers will not have the same address.  On the other hand, a dynamic_cast&lt;Bar*> should work, so somewhere the compiler is storing enough information to figure it out.  Thanks for the help, everybody who answered and commented. I already knew the importance of virtual destructors, as shown in my example; after seeing the answer I gave it a little thought, and realized the whole reason for a virtual destructor is this exact scenario. Thus it had to work. I was thrown by the absence of a visible means of converting the pointer back to the original. A little more thinking led me to believe there was an invisible means, and I theorized that the destructor was returning the true pointer for delete to release. Investigating the compiled code from Microsoft VC++ confirmed my suspicion when I saw this line in ~Base:  mov eax, DWORD PTR _this$[ebp]   Tracing the assembler revealed that this was the pointer being passed to the delete function. Mystery solved.  I've fixed the example to add the virtual destructor to IFoo, it was a simple oversight. Thanks again to everyone who pointed it out. Sum of nilpotent and element is a unit in ring? I can't tell where I went wrong, am still a beginner.    Let N be a nilpotent in a commutive ring , let X be any element.   I'll will be showing X + N is a unit .   Assume Y(X+N) =1   Then YX(N^n-1) =  N^n-1   Multiplying both side by  X+N   We get X(N^n-1) =  X(N^n-1)  Thus nilpotent summed with any element gives unit. Existence in ZF of a set with countable power set Is it consistent with ZF for there to exist a set $S$ such that the power set $P(S)$ is countable? If so, what is the weakest form of the axiom of choice needed to prove that no such set exists? Can you explain the "Axiom of choice" in simple terms? How to use stars and bars for solving number of integral solutions to an equality? How to use the  method?  Say I want to find number of combinations I can get with $x_1+x_2+x_3+x_4=22$,  where $x_i\in\mathbb{N}$.  Is this the correct time to apply the method?  This is being repurposed in an effort to cut down on duplicates, see here:     and here: Prove $kf(x)+f'(x)=0 $ when conditions of Rolle's theorem are satisfied . Prove that if $f$ is differentiable on $ [a,b]$ and if $ f(a)=f(b)=0$ then for any real $k$ there is an $ x \in (a,b) $such that $$kf(x)+f'(x)=0 $$  As all the conditions of Rolle's theorem are satisfied one can say that there is at least one  $c \in (a,b) $ such that $f'(c) =0$ How should I proceed furthur ? How can I use this to get to the required equation ? What is the use case for a Fragment with no UI? Increasing the maximum number of TCP/IP connections in Linux Problem on Linear Diophantine Equation over 3 variables How to solve $ax+by+cz=d$ over integers where $a,b,c,d$ are integers? tar compression without directory structure What's the meaning of this present perfect sentence? Antiderivative of periodic function I practise before the real analysis exam and I got stuck on few excercises.  "if $F$ is an antiderivative of a continuous periodic function and $F$ is bounded, then $F$ is periodic"  $~\to~$ one should give a proof or counterexample.  (I'm convinced it's true, but how to prove it?) How to use grep on column? I want to apply grep on particular column in column command.  myfile.txt  3,ST,ST01,3,3,856 3,ST,ST02,4,9,0234 6,N1,N101,2,3,ST 6,N1,N102,1,60,Comcast 6,N1,N103,1,2,92   My Command:  column -s, -t &lt; myfile.txt | grep -w "ST"   Here I want to only grep the pattern ST in 2nd column. How to do this ?  Expected Result:  3       ST            ST01              3            3            856 3       ST            ST02              4            9            0234 Proving that any permutation in $S_n$ can be written as a product of disjoint cycles I have attempted a proof of this, but upon looking at my notes, I feel it might be incorrect: it is noticeably simpler than the one in my notes.  Proposition: any permutation in $S_n$ can be written as a product of disjoint cycles.  Proof (attempt): $s\in S_n$. Let $\langle s\rangle$ act on $X=\{1,\cdots,n\}$. Define $x\sim x'\iff x'\in\text{Orb}(x)$ for $x,x'\in X:$ this is clearly an equivalent relation, hence the orbits partition $X$. Each orbit corresponds a cycle in $s$, so we are done.  Does this hold, or have I missed something vital? underbrace matrix inside brackets I would like to put an underbrace below the matrix like this:  $$\left(\underbrace{ \left[\begin{array}{ccc}     a&amp;b&amp;c\\     d&amp;e&amp;f\\     g&amp;h&amp;i \end{array}\right]}_{A} \left[\begin{array}{c}     x_1\\     x_2\\     x_3 \end{array}\right]\right)$$     But I don't want the outer brackets \left( and \right) to stretch vertically. I want them to remain as if there was no underbrace. How to achieve that behaviour? What is the difference between linear regression and logistic regression? There is a formal definition for the Big O notation in . Up to now I have come across Big O in Numerical Analysis, Calculus and Algorithms which all are pretty distinct fields. What I am wondering is if that definition is global and is the only one that is used in every field where the Big O is involved or there are other ways that the Big O is defined in other areas  of Mathematics. \sqrt[x]{y} Breaks With unicode-math Is it possible to prove that $1+1 = 2$? Or rather, how would one prove this algebraically or mathematically? "The resource cannot be found." error when there is a "dot" at the end of the url