pass-by-reference

问题 I'm getting build errors when passing an object that implements multiple interface to a function that requires only one of the interfaces. I'm developing a communication package. The package has a Receiver class and a Sender Class. The Receiver class uses a notification interface Receive_Notifier (function object) for handling notifications. Likewise the Sender class uses a notification interface Send_Notifier to handling notifications. interface Send_Notifier { void sending_text(string text)

问题 I'm using an ObjectDataSource to bind data to a GridView; it works fine except that it always creates a new object to use as a data source. I can do all the setup just fine but I cannot use an instance of an existing object to specify as the "data source" for it. Is it possible to do this? If so, how? If it's not possible, why? EDIT: Here's the gist of what's going on (object types changed): On the first page you are editting the attributes for a dog. One of the attributes is "has puppies"

问题 When you have a function like this, the formal parameter is a reference, it becomes another name for the actual argument, so that when we modify the formal parameter inside the function, the original variable outside the function is changed. void add_five(int& a) { a += 5; } int main() { int number = 3; add_five(number); std::cout << number << std::endl; // prints 8 return 0; } I have some code which works on a linked lists. And I am passing two Node* s into the function. void LinkedList:

问题 This question already has answers here : How do I do a deep copy of a 2d array in Java? (6 answers) Closed 6 years ago . I want to make an exact copy of given array to some other array but such that even though I change the value of any in the new array it does not change the value in the original array. I tried the following code but after the third line both the array changes and attains the same value. int [][]a = new int[][]{{1,2},{3,4},{5,6}}; int[][] b = a; b[1][0] = 7; instead of the

问题 I have a class with properties in it (let say the name of the class file is inputvar ), I use it as the input argument for two different functions, which have an exactly the same calculation, but a little bit different code, which I'll explain later. For the first function (let say the name is myfun1), I wrote the input argument like this: f = myfun1 (inputvar) So every time I want to use variables from the class inside the function, I'll have to call inputvar.var1 , inputvar.var2 , and etc.

问题 Is it possible to just reference a entire bytearray in JNI but not invoking any copy ? In native C code, I have a bytearray passing from Java, and I just want to compare some data to this bytearray so I do not want to do any memory copy. Is it possible ? I know I could get the pointer of a bytearray in native by using GetPrimitiveArrayCritical something like that JNIEXPORT jbyteArray JNICALL Java_nfore_android_bt_pro_nfhfp_dsp (JNIEnv *env, jobject jobj, jbyteArray jbIn, jbyteArray jbBase){

问题 I have two functions that I'm using to add or remove slashes from a deeply nested object/array combo. The first "level" of the array is always an object, but some of its properties may be arrays or objects. Here are my two functions: function objSlash( &$obj, $add=true ) { foreach ( $obj as $key=>$field ) { if ( is_object( $field ) ) objSlash( $field, $add ); else if ( is_array( $field ) ) arrSlash( $field, $add ); else if ( $add ) $obj->$key = addslashes( $field ); else $obj->$key =

问题 Passing an object by reference is an easier, faster and safer way to pass an address to it. But for most compilers, it's all the same: references are really pointers. Now what about basic types like int ? Passing an address to an int and using it inside a function would be slower than passing it by copy, because the pointer needs to be dereferenced before use. How do modern compiler handle, this? int foo(const int & i) { cout << i; // Do whatever read-only with i. } May I trust them to

问题 I'm writing a PHP extension that takes a reference to a value and alters it. Example PHP: $someVal = "input value"; TestPassRef($someVal); // value now changed What's the right approach? 回答1: Edit 2011-09-13 : The correct way to do this is to use the ZEND_BEGIN_ARG_INFO() family of macros - see Extending and Embedding PHP chapter 6 (Sara Golemon, Developer's Library). This example function takes one string argument by value (due to the ZEND_ARG_PASS_INFO(0) call) and all others after that by

问题 Check out this code: $last = end($p = explode('/', $someString)); Getting this notice: Only variables should be passed by reference I'm really confused because $p is a variable. 回答1: The function end() expects a real variable and not a function returning an array, but if you put the function return inside double parentheses PHP does not report a strict standards notice: $last = end( ( explode( '/', $someString ) ) ); 回答2: end() expects a variable, not a reference. In your exemple $p = explode