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  • Why does std::cout convert volatile pointers to bool?

    - by Joseph Garvin
    If you try to cout a volatile pointer, even a volatile char pointer where you would normally expect cout to print the string, you will instead simply get '1' (assuming the pointer is not null I think). I assume output stream operator<< is template specialized for volatile pointers, but my question is, why? What use case motivates this behavior? Example code: #include <iostream> #include <cstring> int main() { char x[500]; std::strcpy(x, "Hello world"); int y; int *z = &y; std::cout << x << std::endl; std::cout << (char volatile*)x << std::endl; std::cout << z << std::endl; std::cout << (int volatile*)z << std::endl; return 0; } Output: Hello world 1 0x8046b6c 1

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  • How to declare a 2D array of 2D array pointers and access them?

    - by vikramtheone
    Hi Guys, How can I declare an 2D array of 2D Pointers? And later access the individual array elements of the 2D arrays. Is my approach correct? void alloc_2D(int ***memory, unsigned int rows, unsigned int cols); int main() { int i, j; int **ptr; int **array[10][10]; for(i=0;i<10;i++) { for(j=0;j<10;j++) { alloc_2D(&ptr, 10, 10); array[i][j] = ptr; } } //After I do this, how can I access the 10 individual 2D arrays? return 0; } void alloc_2D(int ***memory, unsigned int rows, unsigned int cols) { int **ptr; *memory = NULL; ptr = malloc(rows * sizeof(int*)); if(ptr == NULL) { printf("\nERROR: Memory allocation failed!"); } else { int i; for(i = 0; i< rows; i++) { ptr[i] = malloc(cols * sizeof(float)); if(ptr[i]==NULL) { printf("\nERROR: Memory allocation failed!"); } } } *memory = ptr; }

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  • How to declare array of 2D array pointers and access them?

    - by vikramtheone
    Hi Guys, How can I declare an 2D array of 2D Pointers? And later access the individual array elements of the 2D arrays. Is my approach correct? main() { int i, j; int **array[10][10]; int **ptr = NULL; for(i=0;i<10;i++) { for(j=0j<10;j++) { alloc_2D(&ptr, 10, 10); array[i][j] = ptr; } } //After I do this, how can I access the individual 2D array //and then the individual elements of the 2D arrays? } void alloc_2D(float ***memory, unsigned int rows, unsigned int cols) { float **ptr; *memory = NULL; ptr = malloc(rows * sizeof(float*)); if(ptr == NULL) { status = ERROR; printf("\nERROR: Memory allocation failed!"); } else { int i; for(i = 0; i< rows; i++) { ptr[i] = malloc(cols * sizeof(float)); if(ptr[i]==NULL) { status = ERROR; printf("\nERROR: Memory allocation failed!"); } } } *memory = ptr; }

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  • Pass array of data to jQuery function

    - by ILMV
    Here's the story... I have a jQuery function that does something, this function is referenced very regularly. One of the input parameters is an array, this array data is hard coded and thus I want to pass the data like this: (this is how I would do it using PHP) myFunction(Array("1"=>"a","2"=>"b","3"=>"c")); Instead of $arr=Array("1"=>"a","2"=>"b","3"=>"c"); myFunction($arr); So how do I achieve this with my jQuery function, I want this to be a one liner if possible.

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  • Specify an inline callback function as an argument.

    - by Matthias Vance
    LS, Let me first explain what I'm trying to achieve using some pseudo-code (JavaScript). // Declare our function that takes a callback as as an argument, and calls the callback with true. B(func) { func(true); } // Call the function B(function(bool success) { /* code that uses success */ }); I hope this says it all. If not, please comment on my question so I can write a little more to clarify my issue. What I want is to have code like this in C++. I have tried to use lambda functions, but I was unable to specify a parameter type for those. Kind regards, Matthias Vance

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  • Javascript function push problem

    - by Stefan
    Hello i've following JS function. responseData:function(resp){ this.jsondata = eval('(' + resp + ')'); this.propList = []; for (var i = 0;i<this.jsondata.length;i++) { for (obj in this.jsondata[i]) { alert(obj); //shows the property name of obj this.propList.push({ obj : this.jsondata[i][obj] //insert only simple obj string }); } } return this.propList; } I want to insert in my propList the property name and the value, but instead inserting the property name this function inserts simple 'obj' as a string. What i'm doing wrong? greetings Stefan

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  • How to call iframe's function from this iframe

    - by Adrian
    Hi, I have an iframe created in Javascript with some function f(): var iframe = document.createElement("iframe"); $(iframe).attr({ width: 0, height: 0, frameborder: 0, src: this.options.url, name: id, id: id }); document.body.appendChild(iframe); iframe.contentWindow.f = function(data) { alert("test"); }; Document loaded in this iframe should call function f(): <script ...>f();</script> And this works perfectly in Firefox but Opera tells, f() is undefined. Is there any solution? Adrian.

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  • Subsetting a data frame in a function using another data frame as parameter

    - by lecodesportif
    I would like to submit a data frame to a function and use it to subset another data frame. This is the basic data frame: foo <- data.frame(var1= c('1', '1', '1', '2', '2', '3'), var2=c('A', 'A', 'B', 'B', 'C', 'C')) I use the following function to find out the frequencies of var2 for specified values of var1. foobar <- function(x, y, z){ a <- subset(x, (x$var1 == y)) b <- subset(a, (a$var2 == z)) n=nrow(b) return(n) } Examples: foobar(foo, 1, "A") # returns 2 foobar(foo, 1, "B") # returns 1 foobar(foo, 3, "C") # returns 1 This works. But now I want to submit a data frame of values to foobar. Instead of the above examples, I would like to submit df to foobar and get the same results as above (2, 1, 1) df <- data.frame(var1=c('1','1','3'), var2=c("A", "B", "C")) When I change foobar to accept two arguments like foobar(foo, df) and use y[, c(var1)] and y[, c(var2)] instead of the two parameters x and y it still doesn't work. Which way is there to do this?

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  • Getting data from function loaded after current function

    - by Hwang
    I have 2 functions, 1 loaded before another. Some value are determine by the other function data, but since one of it has to load before the other 1, how should I get the data that is loaded after current function? private function wMessage():void { Message.width=Name.width+20; } private function wName():void { Name.x=(Message.x+Message.textWidth)-Name.textWidth; Name.y=Message.y+Message.height; } I've taken out some other unnecessary codes, but as you can see Name position is set according by the position + width of Message, but I want Message's width to be not smaller than Name

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  • Please help get this msdn function working to create an auto complete method

    - by Phil
    Here is a method from msdn to provide data to an autocomplete extender / textbox: <System.Web.Services.WebMethodAttribute(), System.Web.Script.Services.ScriptMethodAttribute()> _ Public Shared Function GetCompletionList(ByVal prefixText As String, ByVal count As Integer, ByVal contextKey As String) As String() ' Create array of movies Dim movies() As String = {"Star Wars", "Star Trek", "Superman", "Memento", "Shrek", "Shrek II"} ' Return matching movies Return From m In movies(6) Where _ (m.StartsWith(prefixText, StringComparison.CurrentCultureIgnoreCase)) Select m).Take(count).ToArray() End Function The errors are: m.StartsWith - ('Startswith' is not a member of 'Char') Select m - ('Select Case' must end with a matching end select) .Take(count).ToArray() - (End of statement expected) Can you please let me know how to get this function working? Thanks

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  • How to get the original variable name of variable passed to a function

    - by Acorn
    Is it possible to get the original variable name of a variable passed to a function? E.g. foobar = "foo" def func(var): print var.origname So that: func(foobar) Returns: >>foobar EDIT: All I was trying to do was make a function like: def log(soup): f = open(varname+'.html', 'w') print >>f, soup.prettify() f.close() .. and have the function generate the filename from the name of the variable passed to it. I suppose if it's not possible I'll just have to pass the variable and the variable's name as a string each time.

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  • Get pointer to member function from within member function in C++

    - by Eli
    Currently in the program I am attempting to write I need to be able to get a pointer to a member function within a member function of the same class. The pointer needs to be passed to a function as a void (*)(). Example: //CallFunc takes a void (*)() argument class testClass { public: void aFunc2; void aFunc1; } void testClass:aFunc2(){ callFunc(this.*aFunc1); // How should this be done? } void testClass:aFunc1(){ int someVariable = 1; } I'm trying to do this in GCC 4.0.1. Also, the member function being called can't be static because it references non-static variables in the class that it is part of.

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  • Excel 2003 - ADDRESS() function issues

    - by hairdresser-101
    I finally thought I had found a way to acutally use excel productively but the code that I followed does not appear to work. I'm thinking that the code is very limited and can't do what I want but I thought I'd ask to confirm - maybe it is my function that is the problem. I want to calculate the sum of a row of values for the previous month based on how many days we are into this month (i.e. It is the 20th of April so I want to sum the first 20 days of March to compare against.) =SUM(G4:ADDRESS(ROW(),7+$BR$3,4)) I basically want to SUM(G4:AA4) and have used the address function to return the cell reference AA4 by taking G4 and adding 20 to the column count. ADDRESS(ROW(),7+$BR$3,4) This successfully returns AA7 as expected HOWEVER, when I try to use the returning value in the SUM() function it throws an error... Am I not able to use this reference in my calculation?

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  • Passing parameters to a JQuery function.

    - by jmpena
    Hello, ive a problem using JQuery.. Im creating a HTML with a loop and it has a column for Action, that column is a HyperLink that when the user click the link call a JavaScript function and pass the parameters... example: <a href="#" OnClick="DoAction(1,'Jose');" > Click </a> <a href="#" OnClick="DoAction(2,'Juan');" > Click </a> <a href="#" OnClick="DoAction(3,'Pedro');" > Click </a> ... <a href="#" OnClick="DoAction(n,'xxx');" > Click </a> i want that function to Call an Ajax JQuery function with the correct parameters. any help ??

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  • Default values on arguments in C functions and function overloading in C

    - by inquam
    Converting a C++ lib to ANSI C and it seems like though ANSI C doesn't support default values for function variables or am I mistaken? What I want is something like int funcName(int foo, bar* = NULL); Also, is function overloading possible in ANSI C? Would need const char* foo_property(foo_t* /* this */, int /* property_number*/); const char* foo_property(foo_t* /* this */, const char* /* key */, int /* iter */); Could of course just name them differently but being used to C++ I kinda used to function overloading.

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  • Puzzle: Overload a C++ function according to the return value

    - by Motti
    We all know that you can overload a function according to the parameters: int mul(int i, int j) { return i*j; } std::string mul(char c, int n) { return std::string(n, c); } Can you overload a function according to the return value? Define a function that returns different things according to how the return value is used: int n = mul(6, 3); // n = 18 std::string s = mul(6, 3); // s = "666" // Note that both invocations take the exact same parameters (same types) You can assume the first parameter is between 0-9, no need to verify the input or have any error handling.

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  • Overwriting arguments object for a Javascript function

    - by Ian Storm Taylor
    If I have the following: // Clean input. $.each(arguments, function(index, value) { arguments[index] = value.replace(/[\W\s]+/g, '').toLowerCase(); }); Would that be a bad thing to do? I have no further use for the uncleaned arguments in the function, and it would be nice not to create a useless copy of arguments just to use them, but are there any negative effects to doing this? Ideally I would have done this, but I'm guessing this runs into problems since arguments isn't really an Array: arguments = $.map(arguments, function(value) { return value.replace(/[\W\s]+/g, '').toLowerCase(); }); Thanks for any input. EDIT: I've just realized that both of these are now inside their own functions, so the arguments object has changed. Any way to do this without creating an unnecessary variable?

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  • Powershell function that creates a array by input

    - by user2971548
    I'm quite new to Powershell and working on a little project with functions. What I'm trying to do is creating a function that takes 2 arguments. The first argument ($Item1) decides the size of the array, the second argument ($Item2) decides the value of the indexes. So if I write: $addToArray 10 5 I need the function to create a array with 10 indexes and the value 5 in each of them. The second argument would also have to take "text" as a value. This is my code so far. $testArray = @(); $indexSize = 0; function addToArray($Item1, $Item2) { while ($indexSize -ne $Item1) { $indexSize ++; } Write-host "###"; while ($Item2 -ne $indexSize) { $script:testArray += $Item2; $Item2 ++; } } Any help is appreciated. Kind regards Dennis Berntsson

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  • How does PHP's list function work?

    - by Jacob Relkin
    After recently answering a couple of questions here on SO that involved utilizing PHP's list function, I wondered, "how in the world does that function actually work under the hood?". I was thinking about something like using func_get_args() and then iterating through the argument list, and that's all nice and peachy, but then how in the world does the assignment part work? list(...) = array($x, $y, $z); isn't this ^ evaluated first? So to be precise, my question is how is the list function able to create scoped variables which get assigned to the not-yet evaluated array?

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  • Create function in python to find the highest of all function arguments, and return the "tag" of the value.

    - by gatechgrad
    Consider the following: p1=1; p2=5; p3=7; highest=max(p1,p2,p3). The max function would return 7. I am looking to create a similar function, which would return "p3". I have created a small function (by simple comparisons) for the above example, shown below. however I am having trouble when the number of arguments go up. def highest(p1,p2,p3) if (p1p2) and (p1p3): return "p1" if (p2p1) and (p2p3): return "p2" if (p3p1) and (p3p1): return "p3". Is there a simpler way to do this

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  • Jquery Javascript function, simple error, can't find it!

    - by CodingIsAwesome
    When my page loads it calls the function like below: <body onLoad='changeTDNodes()'> And the code it calls is below: enter code here <script src='jquery-1.4.2.min.js' type='text/javascript'></script> <script> function changeTDNodes() { var threshValue = 10; $(".threshold").each(function(elem) { if($("b",elem).innerText > threshValue) { elem.addClass("overThreshold"); } }); }); } I have the class setup correctly in CSS .overThreshold { td{font-size:72px;} th{font-size:72px;} } But no classes are being changed, whats going on? Thanks for all your help!

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  • Rewriting usort function because of fatal error (PHP bug)

    - by Lionel
    The two following usort functions throw fatal error Base lambda function for closure not found in our productive environment (PHP 5.4). This seems to be a known PHP bug that should be fixed by now (https://bugs.php.net/bug.php?id=52144), but it still occurs for us. Anyway, we unfortunately don't have time to figure out what's wrong with our PHP configurations etc. We would like to rewrite these two functions without the use of anonymous functions, so that the error doesn't occur anymore. Ordering of a multidimensional array ($array) by value of key "position": usort($array, function($a, $b) { return $a['position'] - $b['position']; }); Ordering of a multidimensional array ($array) according to the order of a second array ($position_order): usort($array, function($a, $b) use($position_order) { return (isset($position_order[$a['ftid']]) ? ($position_order[$a['ftid']] - $position_order[$b['ftid']]) : 1); }); Especially the latter causes some headache, as we don't know how to pass the "outside" array $position_order.

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  • template function roundTo int, float -> truncation

    - by Oops
    Hi, according to this question: http://stackoverflow.com/questions/2833730/calling-template-function-without-type-inference the round function I will use in the future now looks like: template < typename TOut, typename TIn > TOut roundTo( TIn value ) { return static_cast<TOut>( value + 0.5 ); } double d = 1.54; int i = rountTo<int>(d); However it makes sense only if it will be used to round to integral datatypes like char, short, int, long, long long int, and it's unsigned counterparts. If it ever will be used with a TOut As float or long double it will deliver s***. double d = 1.54; float f = roundTo<float>(d); // aarrrgh now float is 2.04; I was thinking of a specified overload of the function but ... that's not possible... How would you solve this problem? many thanks in advance Oops

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  • How to access a function inside a function? Python

    - by viddhart
    I am wondering how I can access a function inside another function. I saw code like this: >>> def make_adder(x): def adder(y): return x+y return adder >>> a = make_adder(5) >>> a(10) 15 So, is there another way to call the adder function? And my second question is why in the last line I call adder not adder(...)? Good explanations are much appreciated.

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