I'm currently following a quick tutorial. And the XOR "^" symbol has cropped up in a place I've never seen it before. Exactly where the asterisk would be if I were declaring a pointer to an object.  See it in the code snippet below.  COpenGL(System::Windows::Forms::Form ^ parentForm,              GLsizei iWidth, GLsizei iHeight)     {         CreateParams^ cp = gcnew CreateParams;          // Set the position on the form         cp-&gt;X = 100;         cp-&gt;Y = 100;         cp-&gt;Height = iWidth;         cp-&gt;Width = iHeight;   Afterwards the object cp is dereferenced as if it were a pointer to an object of CreateParams type.  So....what does the ^ mean? Google has not been too friendly.
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I just came across this code and a few Google searches turn up no explanation of this mysterious (to me) syntax.  Hashtable^ tempHash = gcnew Hashtable(iterators_);  IDictionaryEnumerator^ enumerator = tempHash-&gt;GetEnumerator();   What the heck does the caret mean? (The gcnew is also new to me, and I asked about that .)
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I haven't written any C++ in years and now I'm trying to get back into it. I then ran across this and thought about giving up:  typedef enum TokenType {     blah1   = 0x00000000,     blah2   = 0X01000000,     blah3   = 0X02000000 } TokenType;   What is this? Why is the typedef keyword used here? Why does the name TokenType appear twice in this declaration? How are the semantics different from this:  enum TokenType {     blah1 = 0x00000000,     blah2=0x01000000,     blah3=0x02000000 };
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What does the :0.0 actually mean? I know that :0 is the first X server that is started on a local machine, :1 the second, etc. But what is that .0 part after :0? Do other combinations exist? (e.g. :0.0-something)  Background: I'm trying to improve the initscript of  which currently assumes that :0 is the active display. That is not the case if I switch users. So I wanted to validate the $DISPLAY variable before passing it to vglclient.
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I came across this strange code snippet which compiles fine:  class Car {     public:     int speed; };  int main() {     int Car::*pSpeed = &amp;Car::speed;     return 0; }   Why does C++ have this pointer to a non-static data member of a class? What is the use of this strange pointer in real code?
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I extracted simple example:  require 'pp' x = 1..3 pp x.map do |i| {:value =&gt; i, :double =&gt; (i*2)} end pp x.map { |i| {:value =&gt; i, :double =&gt; (i*2)} }  pp(x.map do |i| {:value =&gt; i, :double =&gt; (i*2)} end) pp(x.map { |i| {:value =&gt; i, :double =&gt; (i*2)} })   I am wondering why first pp produces:  [1, 2, 3]   While all the oders are giving:  [{:value=&gt;1, :double=&gt;2}, {:value=&gt;2, :double=&gt;4}, {:value=&gt;3, :double=&gt;6}]   I assume it has something to do with operator precedence. Where can I find good explanation?
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When {0} is used to initialize an object, what does it mean? I can't find any references to {0} anywhere, and because of the curly braces Google searches are not helpful.  Example code:  SHELLEXECUTEINFO sexi = {0}; // what does this do? sexi.cbSize = sizeof(SHELLEXECUTEINFO); sexi.hwnd = NULL; sexi.fMask = SEE_MASK_NOCLOSEPROCESS; sexi.lpFile = lpFile.c_str(); sexi.lpParameters = args; sexi.nShow = nShow;  if(ShellExecuteEx(&amp;sexi)) {     DWORD wait = WaitForSingleObject(sexi.hProcess, INFINITE);     if(wait == WAIT_OBJECT_0)         GetExitCodeProcess(sexi.hProcess, &amp;returnCode); }   Without it, the above code will crash on runtime.
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I've never been a fan of Hungarian notation, I've always found it pretty useless unless you're doing some really low level programming, but in every C++ project I've worked on some kind of Hungarian notation policy was enforced, and with it the use of some 'not-really-Hungarian' prefixes as m_ for fields, s_ for statics, g_ for globals and so on.  Soon I realized how much useless it was in C# and gradually started to drop all of my old habits... but the 'm_' thing. I still use the m_ prefix on private fields because I really find it very useful to being able to distinguish between parameters, locals and fields.  The  says I shouldn't, but it does not say why (the way e.g. Google's conventions generally tend to rationalize their prescriptions).  Are there reasons why I shouldn't or is it only a matter of style. If it is the latter, are prefixes generally considered a bad style and can I expect negative reactions from other people working on the codebase?
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This seems like a simple question, but I can't find it with the Stack Overflow search or Google. What does a type followed by a _t mean? Such as  int_t anInt;   I see it a lot in C code meant to deal closely with hardware—I can't help but think that they're related.
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I very rarely meet any other programmers!  My thought when I first saw the token was "implies that" since that's what it would read it as in a mathematical proof but that clearly isn't its sense.  So how do I say or read "=>" as in:-  IEnumerable&lt;Person&gt; Adults = people.Where(p =&gt; p.Age &gt; 16)   Or is there even an agreed way of saying it?
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What does the explicit keyword mean in C++?
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Here is a quick question, how to use tex to print this ' symbol? An example is shown below:  data 'a list = Nil | Cons (e, 'a list)   I tried to use ' or `, but they all looks bad.. I am sorry but I am not a native English speaker, so I don't even know the name of '..   Could anyone help me on this simple problem? thank you
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Situation: It started out as me  for the literal string C-c in  but it ended up omitting the - sign and showing results which contained the strings C/C++ and C &amp; C++.  is an example of a post which contains that string of characters (yet fails to show up in the results).  Things I've tried:   post suggests that I can use the undocumented code: operator, but when I do that, it just wraps the whole term in double quotes like .  As @terdon in Unix &amp; Linux chat has , using this  does yield some relevant results, but it doesn't show me  that is supposed to be there. edit: It appears that the Symbolhound query no longer returns that result.  Finally,  says that you can search for literal characters, but as you can see:    Quoted phrases are exact matches except for case-sensitivity, for example, you can search  or .  The second example (symbols) leads to 0 results.  So by now I assume that the search engine has changed (but the old documentation still lingers on this site). Is there a method for me to search for strings that include special (or is it literal?) characters?
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How can I typeset the following symbol for direct current (i.e. a = symbol where the lower line is dashed)?     The image above is an enlarged version, the size I need is like =, \approx, \simeq etc.
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In C/C++, what an unsigned char is used for? How is it different from a regular char?
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byte x = -1; for(int i = 0; i &lt; 8; i++) {     x = (byte) (x &gt;&gt;&gt; 1);     System.out.println("X: " + x); }   As I understand it, java stores data in two's-complement, meaning -1 = 11111111 (according to wikipedia).    Also, from the java docs: "The bit pattern is given by the left-hand operand, and the number of positions to shift by the right-hand operand. The unsigned right shift operator ">>>" shifts a zero into the leftmost position, while the leftmost position after ">>" depends on sign extension. "  Which means that >>> would shift a 0 to the left most bit every time.  So I expect this code to be  iteration: bit representation of x  0: 11111111  1: 01111111  2: 00111111  3: 00011111  ...so on  However, my output is always X: -1, meaning (I guess) that >>> is putting the sign bit in the left most position.  So I then try >>, and same result.  What's going on?  I would expect my output to be: X: -1, x: 127, x: 63, etc.
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To mean that x is an element of X, we can write x \in X. However, in the standard packages, the membership symbol that results is too big; it draws too much attention to itself. This is especially evident when we're doing set theory and writing sets as lowercase, as in x \in y. Does anyone one how to draw a less attention-seeking membership symbol?
107627
Is it the same convention as those used in known programming languages such as Java and C? I'm trying to create a lot of variables and I want it to start with a number, but I'm not sure if it's okay.