variadic-functions

问题 I am writing an adapter to combine two APIs (one in C and another in C++). If a function is called on the one API I need to pass the callers ID and the function's arguments to an adapter and call the according function with this information passed. Now aparently they can not be mapped directly as one interface requires C++ compilation and the name mangling would screw the other so that is why I am using a set of adapters in the first place. As the number of arguments varies, I looked up

问题 I need to build a set of input for different workflows using 1 or more outputs from previous workflows, when i do this public interface InputBuilder<I extends SwfInput, O extends SwfOutput> { public I buildInput(O... output); } public class SwfAuthorisationInputBuilder implements InputBuilder { @Override public SwfAuthorisationInput buildInput(SwfOutput swfEventInitOutput) { SwfEventInitOutput output = (SwfEventInitOutput ) swfEventInitOutput; SwfAuthorisationInput authorisationInput =

问题 I have to execute several lambda functions, but every each N lambdas a prologue() function also must be run. The number of lambdas can be arbitrary large and N is known at compile time. Something like this: static void prologue( void ) { cout << "Prologue" << endl; } int main() { run<3>( // N = 3 [](){ cout << "Simple lambda func 1" << endl; }, [](){ cout << "Simple lambda func 2" << endl; }, [](){ cout << "Simple lambda func 3" << endl; }, [](){ cout << "Simple lambda func 4" << endl; }, [](

问题 I'd like a step by step explanation on how to parse the arguments of a variadic function so that when calling va_arg(ap, TYPE); I pass the correct data TYPE of the argument being passed. Currently I'm trying to code printf. I am only looking for an explanation preferably with simple examples but not the solution to printf since I want to solve this personal challenge myself to progress. Link1, link2 and link3 are examples which I think are part of what I'm looking. I the basics of what a

问题 I am writing a C program that will take a variable number of command line arguments. I need to then take these arguments and pass them into a function that takes a variable number of filenames as individual parameters (using va_arg to get the arguments inside the function), prototyped as: void FindFile(char *filename1, ...); My implementation of FindFile is fine. My question is, how do I take the variable number of arguments in the main method's 'char *argv[]' and use them as parameters when

问题 This question already has answers here : What does `:_*` (colon underscore star) do in Scala? (4 answers) Closed 4 years ago . I'm learning Scala and I just faced variadic functions. It's almost all ok on the example below I wrote: object Sscce { def main(args: Array[String]) { printStrings("Hello", "Scala", "here", "I", "am"); } def printStrings(ss: String*): Unit = { if (!ss.isEmpty) { println(ss.head) printStrings(ss.tail: _*) } } } I understand that String* means a variable list of

问题 I use java 7, and I create a varargs method public class JavaApplicationTest { /** * @param args the command line arguments */ public static void main(String[] args) { addBundleMessage("b", Integer.SIZE, "key", (Object) null); } public static void addBundleMessage(String bundleName, Integer severity, String key, Object... params) { if (params == null) System.out.println("params Is null"); else System.out.println("Params not null"); } } If I don't cast the object, the IDEs Netbeans or Eclipse

问题 I have been working on a small project to get up to speed with variadic templates. I implemented a small multidimensional array. I would now like to define a function that operates on the nearest neighbours of a given position -- is there an elegant way to retrieve the values of the neighbours of a given position in my array? template<class T, size_t size, size_t... sizes> struct MArr { typedef std::array<typename MArr<T, sizes...>::type, size> type; std::array<MArr<T, sizes...>,size> data;

问题 As you can see in the example below, map function in Scheme is variadic function. > (map (lambda (number1 number2) (+ number1 number2)) '(1 2 3 4) '(10 100 1000 10000)) '(11 102 1003 10004) I want to implement this variadic option, but I only succeeded to find the two arguments map implementation: (define (map f lst) (if (null? lst) '() (cons (f (car lst)) (map f (cdr lst))))) Can someone help me implement variadic map function? 回答1: In Scheme, you can write a variadic function as (lambda x .

问题 So I have a function that takes a variable length argument list, for example: int avg(int count,...){ //stuff } I can call it with avg(4,2,3,9,4); and it works fine. It needs to maintain this functionality. Is there a way for me to also call it with an array instead of listing the variables? For example: avg(4,myArray[5]) such that the function avg doesn't see any difference? 回答1: No there is no such way. You can however make two functions, one that takes a variable number of arguments, and