overloading

问题 Why I cant overload Method with dynamic and object Parameters. void Method(dynamic arg) // Member with same signature is already declared { Console.WriteLine("Dynamic"); } void Method(object arg) // Member with same signature is already declared { Console.WriteLine("Not Dynamic"); } But I can overload Method with dynamic and another type except object or dynamic it self. void Method(dynamic arg) { Console.WriteLine("Dynamic"); } void Method(string arg) { Console.WriteLine("Not Dynamic"); } As

问题 Why I cant overload Method with dynamic and object Parameters. void Method(dynamic arg) // Member with same signature is already declared { Console.WriteLine("Dynamic"); } void Method(object arg) // Member with same signature is already declared { Console.WriteLine("Not Dynamic"); } But I can overload Method with dynamic and another type except object or dynamic it self. void Method(dynamic arg) { Console.WriteLine("Dynamic"); } void Method(string arg) { Console.WriteLine("Not Dynamic"); } As

问题 Following the pattern recommended in this question, where we have something akin to: function foo(a, b, opts) { } foo(1, 2, {"method":"add"}); foo(3, 4, {"test":"equals", "bar":"tree"}); How would one then include a callback as the final parameter? I have function foo() that should be able to handle both of: foo(x, y, function() { // do stuff }); And foo(x, y, z, function() { // do stuff }); Any suggestions? 回答1: So basically you want to accept a variable number of arguments, followed by a

问题 What is the best way of supporting optional data passed to a C# function? I have web service function in .Net which defines 5 arguments: [WebMethod] public string UploadFile( string wsURL , byte[] incomingArray , string FileName , string RecordTypeName , MetaData[] metaDataArray) The code of this function is not too long (but not trivial either) and there is only one place in the the function where I perform this test if there is any MetaData[] to be processed: if (metaDataArray.Length > 0) {

问题 The following does not compile (Apple LLVM version 4.2 (clang-425.0.28)): class A { public: virtual void foo() {}; virtual void foo( int i ) {}; }; class B : public A { public: virtual void foo( int i ) override { foo(); } }; The compiler error is "Too few arguments" for the call to foo() inside B::foo(int). The compiler apparently thinks that I want to recursively call B::foo(int) and does not recognize that I want to call A::foo(void). The error goes away if I replace the call to foo() by A

问题 This question already has answers here : Why is method overloading and overriding needed in java? [duplicate] (3 answers) Closed 3 years ago . Since I have found so many examples and conclusions about Method Overloading but still I am confusing in real time how we are using it. First of all method overloading is a class level activity means within that class we are overloading a method with same name but different arguments like void sum(int a,int b){System.out.println(a+b);} void sum(double

问题 For clarity I will extract an excerpt from my code and use general names. I have a class Foo() that stores a DataFrame to an attribute. import pandas as pd import pandas.util.testing as pdt class Foo(): def __init__(self, bar): self.bar = bar # dict of dicts self.df = pd.DataFrame(bar) # pandas object def __eq__(self, other): if isinstance(other, self.__class__): return self.__dict__ == other.__dict__ return NotImplemented def __ne__(self, other): result = self.__eq__(other) if result is

问题 I have a code and I am not able to get why the output will be "Radial Tire with long".Can somebody help me to understand this code? class Tyre { public void front() throws RuntimeException { System.out.println("Tire"); } public void front(long a) { System.out.println("Radial Tire with long"); } } class TestSolution extends Tyre { public void front() { System.out.println("Radial Tire"); } public void front(int a) throws RuntimeException { System.out.println("Radial Tire with int"); } public

问题 How can I overload the STL implementation for methods like find, erase and insert to take varying parameters? I tried to look up the overloading of STL methods but couldn't find any help. 回答1: You can't overload the methods of a class without editing the code of that class. Write your own free functions that act as helpers; they would take the relevant container class as the first parameter. You can inherit from a class and add methods that way, but the std container classes are not designed

问题 Why is it that Fortran will promote a scalar expression to an array, in an expression , but not as an argument to a procedure? In particular, why did the standards body make this design decision? Is it solely because of ambiguity, should the procedure be overloaded? Could an error message in that situation be an alternative approach? For example, In the code below, the last statement, x = foo(7) , produces the GFortran error: Error: Rank mismatch in argument 'a' at (1) (1 and 0) . module m