overloading

问题 If I have the following code in Java: class A { public int add(int a , int b) { return (a+b); } } class B extends A { public float add(float a , float b) { return (a+b); } In this particular case the sub-class isn't exactly overriding the base class's add function as they have different signatures and the concept of overloading occurs only if they are in the same scope. So, is the function add(float , float) in the sub-class B treated as an entirely new function and the concept of overloading

问题 Java typically prefers normal methods to generic ones when choosing which overloaded method is correct, which could generate the following sscce: public class GenericsTest { public static void main(String[] args) { myMethod(Integer.class, 10); myMethod(String.class, "overloaded method"); } public static <T> void myMethod(Class<T> klass, T foo) { System.out.println("hello world"); } public static <T> void myMethod(Class<T> klass, String bar) { System.out.println(bar); } } Output: hello world

问题 Consider the function bar below, whose parameter has a default value initialized from an invocation of an overloaded foo : #include <iostream> int foo(int x) { std::cout << "foo(int)" << std::endl; return 0; } template<typename T> void bar(T a, int x = foo(T(0))) {} double foo(double x) { std::cout << "foo(double)" << std::endl; return 0; } int main() { bar<int>(1); bar<double>(1); return 0; } I expect this program to output foo(int) foo(double) corresponding to foo 's two overloads which are

问题 I want to create proxies for member functions and operators. They must have the same return type and parameters, and must be good for several classes, which are given as template parameters. Even if the class does not have the particular member function or operator, I want it to compile instead of failing with an error, essentially SFINAE. If X has a method f() and Y does not have any method named f , I need Proxy<X> to have an f() as well that calls X::f() , and I need Proxy<Y> to compile

问题 I try to follow this article: http://flipcode.com/archives/How_To_Find_Memory_Leaks.shtml to overload my new and delete functions in order to track memory leaks. however - if I try to compile, I get a C2365: "operator new": redefinition; previous definition was a "function" in the file xdebug xdebug gets included in xlocale - however, i can't find where my project is including xlocale I'm using MFC for multithreading in my project. Can someone tell me how I can get my memory leak tracking to

问题 In VB.NET, which is better to use: function overloading or default parameters? 回答1: Is the code going to be used by other languages? If so, that swings the balance towards overloads while still bearing Hamish's answer in mind. In particular, C# doesn't support optional parameters - yet... Admittedly this wouldn't actually prevent someone using your code from C#, it just might be a pain for them. If there are a lot of parameters and they logically represent something, you might want to

问题 This may have been answered before. I see many "dynamic method overload resolution" questions, but none that deal specifically with passing a dynamic argument. In the following code, in Test , the last call to M cannot be resolved ( it doesn't compile ). The error is: the call is ambiguous between [the first two overloads of M ] . static void M(Func<int> f) { } static void M(Func<string> f) { } static void M(Func<dynamic> f) { } static dynamic DynamicObject() { return new object(); } static

问题 Here is a code sample: class Program { static void Main(string[] args) { var obj = new DerivedClass(); obj.SomeMethod(5); } } class BaseClass { internal void SomeMethod(int a) { } } class DerivedClass : BaseClass { internal void SomeMethod(long a) { } } Can somebody explain me why is a method from derived class called (instead of base class method)? I need a detailed explanation for this situation. I will be grateful for links to any useful articles. Thanks. 回答1: The precise wording and

问题 I have a bunch of printf debug helper macros and it would be pretty cool to have to not specify the type, is there anything you can do to allow something like macro overloading in c(can be gcc specific if its available in gcc 4.3). I thought maybe typeof but apparently that doesn't work. example macro(I also have some ascii terminal color stuff that I can't remember of the top of my head) #ifdef _DEBUG #define DPRINT_INT(x) printf("int %s is equal to %i at line %i",#x,x,__LINE__); . . . #else

问题 Is it possible to overload a function in a Matlab class that you've created? Like the following: function [ sigma_nc ] = sustained_interference( N ) sustained_interference( N, N.center_freq); end function [ sigma_nc ] = sustained_interference( N, center_freq ) ... end Unfortunately when I try this, I get a redefinition error 回答1: If you create the function using the latter, then you can pass it just a single parameter which will be interpreted as the first. If you want default values, then