This works: #include<cstdio> class A{ public: A(int a):var(a){} int var; }; int f(A obj) { return obj.var; } int main() { std::cout<<f(23); // output: 23 return 0; } while this doesn't: #include<cstdio> class A{ public: A(int a, int b):var1(a), var2(b){} int var1, var2; }; int f(A obj) { return (...
Do Android have any way to instantiate objects without calling any of its constructors? In Java, Sun have sun.reflect.ReflectionFactory.getReflectionFactory().newConstructorForSerialization(), in .Net we have System.Runtime.Serialization.FormatterServices.GetUninitializedObject() but I was not able to find anything like that in the And...
I'm trying to learn about new feature of C++ namely move constructor and assignment X::operaror=(X&&) and I found interesting example but the only thing I quite not even understand but more dissagree is one line in move ctor and assignment operator (marked in the code below): MemoryBlock(MemoryBlock&& other) : _data(NULL) , _leng...
How come anonymous functions works as arguments on methods, but not in constructor arguments? If I create a List<string>, it has a Sort method with the following signature: public void Sort(IComparer<T> comparer) where the following works: List<string> list = new List<string>(); list.Sort( (a,b) => a.CompareTo(b) ); SortedSet ha...
Are there any languages that support easily extending the compiler to support new literals example such as for json/xml/yaml/different string encodings/extra number types. I understand that you can always fork the compiler, write a dsl but that's not quite what I'm asking about. I understand that some languages such as smalltalk and lisp...
When i create a mock object of say class Employee. It doesnt call the constructor of Employee object. I know internally Mockito uses CGLIb and reflection, creates a proxy class that extends the class to mock. If it doesnt call the constructor of employee how is the mock instance of employee class created ? ...
In my Hibernated system, I have a class Picture that has some simple data, a list of Installations and some (huge) binary data. The list of Installations is implemented with a join table, as it's a ManyToMany relation, and it's defined on the Installation side: @Entity public class Picture { @Id private long pictureId; private Str...
I have the following class: class Step(kind:TipoStep.Value, message:String = "", study:List[Formula] = List(), lastAdd:Set[Formula] = Set(), lastDel:Set[Formula] = Set(), add:List[Formula] = List(), del:List[Formula] = List() ) { def this(step:Step, ...
It seems impossible to create an object using its default constructor when there is a static .New() method defined on the class: .NET class: public class Tester { public static void New() { Console.WriteLine("In Tester.New()"); } public Tester() { Console.WriteLine("In constructor"); } } IronR...
I have a class, class MyClass { private int val; public static final MyClass myObject = new MyClass(1); MyClass(int a){ val = a; } public int getVal(){ return val; } public MyClass func1(){ MyClass temp = myObject; temp.val = 2; return temp; } public static void...
C# in VS2005: if a class has two constructors, what is the best way for these constructors to share some code? eg. How could I avoid having the x = 5 and y = 10 lines in both constructors for the following: public class MyObject { int x; int y; int z; public MyObject() { x = 5; y = 10; } public MyObject(int setZ) { x = ...
For C# in VS2005, will calling this() in an inherited class cause the execution of the base constructor? EDIT: How can I avoid having to re-write the x and y assignments? Note, I do not want the MyObject(int num) constructor to execute the base() contructor. public class MyObject : MyParentObject { int x; int y; int z; public M...
Hi. Here's what I thought of doing : A - Structure { Position Name } B1 - Vehicle { Fuel } B2 - Building { -nothing- } foo - Car foo2 - Truck bar - Hospital bar2 - Market It's impossible to declare constructors like the following since A is not the direct base class : foo(x,y,z):A(x,y,z) bar(a,b,c):A(a,b,c) So I tried doing...
I have the next code: class Foo { public Foo (String param) { ... } } class Bar extends Foo { public Bar () { super (doSmth()); ... } private static String doSmth () { //what I can NOT do here? } } I wonder is it safe? Are there any limitations about doSmth method? ...
class foo { public: int a; int b; foo(int a_, int b_) : a(a_), b(b_) {} }; int main() { foo f; } when I try to compile the above code snippet, I got error message as below: foo.cc: In function 'int main()' foo.cc:12: error: no matching function for call to 'main()::foo::foo()' foo.cc:10: note: candidates are: main()::foo...
As we know we can instantiate an object without new keyword by using classloader/object cloning/object serialization. When I am using these techniques to create an object, is the constructor called or not? ...
Hi, I have an abstract class A that define abstract methods. This means that, for a class to be instanciable, all the abstract method have to be implemented. I'd like all my subclasses to implement a constructor with 2 ints as parameters. Declaring a constructor defeats my purpose, as I want the constructor defined in subclasses and ...
I have a class "MyEntity", which does not have a default constructor (well, it does, yet it is not suitable for use). I have a form with a DataGrid, which has a cool feature for creating new rows. Problem: DataGrid cannot create new object when no parameterless constructor is defined. Question: is there a way to provide the DataGrid w...
I am trying to block access to the default constructor of a class I am writing. The constructor I want others to use requires a const reference to another object. I have made the default constructor private to prevent others from using it. I am getting a compiler error for the default constructor because the const reference member var...
I know that when inheriting classes, you can also inherit Constructors example: class Book : Genre { Book(string param1, int param2, string inherit1, string inherit2) : Base(inherit1,inherit2) { Prop1 = param1 Prop2 = param2 } } But wouldn't it just be easier to set the inherited properties via the constru...