argument-passing

问题 A very basic question, but still, it would be good to hear from C++ gurus out there. There are two rather similar ways to declare by-reference parameters in C++. 1) Using "asterisk": void DoOne(std::wstring* iData); 2) Using "ampersand": void DoTwo(std::wstring& iData); What are implications of each method? Are there any gotcha's in any case? Bonus #1: What would be a formal way to call method in #1 and #2? Are they both called "by-reference"? Bonus #2: std::wstring is used deliberately. What

问题 This is related to the following post Problems passing arguments with callNextMethod() in R I am writing accessors for two S4 classes, 'foo' and 'bar'. 'bar' inherits from foo and is extended only by a few slots. Instead of writing a full accessor function for objects of class 'bar' I want to pass the arguments to callNextMethod() when accessing a slot that is inherited by 'foo'. My code looks like this: foo <- setClass("foo", representation(x = "numeric", y = "numeric")) bar <- setClass("bar

问题 I am needing to find the argument passed to a function from the function. Let us suppose I have a function called foo : function foo() { var a = 3; var b = "hello"; var c = [0,4]; bar(a - b / c); bar(c * a + b); } function bar(arg) { alert(arg) } As it is now, of course, bar will always alert NaN . Inside of the function bar , I want to obtain the argument in the form it was originally passed. Furthermore, I want to be able to access the values of a , b , and c from the bar function. In other

问题 I am needing to find the argument passed to a function from the function. Let us suppose I have a function called foo : function foo() { var a = 3; var b = "hello"; var c = [0,4]; bar(a - b / c); bar(c * a + b); } function bar(arg) { alert(arg) } As it is now, of course, bar will always alert NaN . Inside of the function bar , I want to obtain the argument in the form it was originally passed. Furthermore, I want to be able to access the values of a , b , and c from the bar function. In other

问题 I need some advice on "forwarding" arguments to a callee (in the LLVM-IR). Suppose I have a function F that is called at the beginning of all other functions in the module. From F I need to access (read) the arguments passed to its immediate caller. Right now to do this I box all arguments in the caller inside a struct and pass a i8* pointer to the struct to F , alongside an identifier telling which caller F is being called from. F has then a giant switch that branches to the appropriate

问题 My question: Why is callNextMethod() not passing arguments as expected to the next method? Situation: Say I have two hierarchical classes foo and bar ( bar is subclass of foo ) for which I have a method foobar that can dispatch for both classes (i.e., has methods for both classes). Furthermore, the method for the (sub)class bar calls the method for foo after some calculations with callNextMethod() . Both methods have the same additional argument (with default) that should be passed to the

问题 Are there any plans to implement ruby behavior similar to the CoffeeScript feature of specifying an instance variable name in a method argument list? Like class User def initialize(@name, age) # @name is set implicitly, but @age isn't. # the local variable "age" will be set, just like it currently works. end end I'm aware of this question: in Ruby can I automatically populate instance variables somehow in the initialize method? , but all the solutions (including my own) don't seem to fit the

问题 In summary, I am using my script 'Graphs.R' on 'input_file1.txt' in RStudio to create a Rmd which I then knit to html. I would like to automate this process to run more files on the command line. So far, I can get the Rscript to run on the command line using: Rscript Graphs.R input_file1.txt I also know that I can create an .RMD file using: Rscript -e rmarkdown::render(Graphs.R) However, I would like to do the following: Rscript -e rmarkdown::render('Graphs.R input_file1.txt', 'output_file

问题 I would like to pass an object as parameter to an Onclick function inside a string. Something like follwing: function myfunction(obj,parentobj){ var o=document.createElement("div"); o.innerHTML='<input type="button" onclick="somelistener(' + obj + ')" />'; parentobj.appendChild(o.firstChild); } Obviously, this doesn't work. Anyone has any idea? THX! A more complete version, as suggested by @Austin <!DOCTYPE html> <html> <body> <style type="text/css"> </style> <p id="test">test</p> <p id=

问题 I am writing a method were I would like to pass a class to a method, where a part of the code includes checking if the object is of a certain type. This is what I want (but which obviously doesn't work): private static class MyClass1 { /***/ } private static class MyClass2 { /***/ } private void someFunc() { /* some code */ methodName(MyClass1); methodName(MyClass2); } private void methodName(Class myClass) { Object obj; /* Complicated code to find obj in datastructure */ if (obj instanceof