multiple-inheritance

问题 I have a class A that has to extend class B and C which are both provided by 3rd party and I don't have a control of them. Since Java doesn't support multiple inheritance. Using interface wouldn't help in my case since I do want to inherit the base classes' implementation and I don't want to copy their code over to my class, or I'll need to be aware of all their coming changes. What would be the best way to accomplish this need? All suggestion will be much appreciated! 回答1: class A class B2

问题 This question already has answers here : Closed 10 years ago . Possible Duplicates: Cheat single inheritance in Java !! Why is Multiple Inheritance not allowed in Java or C#? Multiple Inheritance in java. I know that we can use interfaces to inherit from multiple classes but is it possible to inherit the state as well? How can I inherit methods with definitions from 2 classes and have them in a third class in Java? 回答1: Multiple inheritance is not allowed in Java. Use delegates and interfaces

问题 This question already has answers here : Closed 10 years ago . Possible Duplicates: Cheat single inheritance in Java !! Why is Multiple Inheritance not allowed in Java or C#? Multiple Inheritance in java. I know that we can use interfaces to inherit from multiple classes but is it possible to inherit the state as well? How can I inherit methods with definitions from 2 classes and have them in a third class in Java? 回答1: Multiple inheritance is not allowed in Java. Use delegates and interfaces

问题 This question already has answers here : Closed 10 years ago . Possible Duplicates: Cheat single inheritance in Java !! Why is Multiple Inheritance not allowed in Java or C#? Multiple Inheritance in java. I know that we can use interfaces to inherit from multiple classes but is it possible to inherit the state as well? How can I inherit methods with definitions from 2 classes and have them in a third class in Java? 回答1: Multiple inheritance is not allowed in Java. Use delegates and interfaces

问题 This question already has answers here : Closed 10 years ago . Possible Duplicates: Cheat single inheritance in Java !! Why is Multiple Inheritance not allowed in Java or C#? Multiple Inheritance in java. I know that we can use interfaces to inherit from multiple classes but is it possible to inherit the state as well? How can I inherit methods with definitions from 2 classes and have them in a third class in Java? 回答1: Multiple inheritance is not allowed in Java. Use delegates and interfaces

问题 I'm trying to write some metaprogramming code such that: Inheriting from some class foo<c1, c2, c3, ...> results in inheritance from key<c1>, key<c2>, key<c3>, ... The simplest approach doesn't quite work because you can't inherit from the same empty class more than once. Handling the "..." portion isn't pretty (since it's copy-pasta), but works. Okay, so, here's the attempt: template<char c0, typename THEN, typename ELSE> struct char_if { typename THEN type; }; template<typename THEN,

问题 I am defining a DoubleWrapper class inheriting from two CRTP base classes, Ratioable and Divable , that both define operator/() , with different signatures: T operator/(double const& scalar) const { return T(this->underlying().get() / scalar); } double operator/(T const& other) const { return this->underlying().get() / other.get(); } They differ both by return type and parameter type. However compiler is complaining about operator/() being ambiguous. Note that the constructor is explicit so

问题 I am defining a DoubleWrapper class inheriting from two CRTP base classes, Ratioable and Divable , that both define operator/() , with different signatures: T operator/(double const& scalar) const { return T(this->underlying().get() / scalar); } double operator/(T const& other) const { return this->underlying().get() / other.get(); } They differ both by return type and parameter type. However compiler is complaining about operator/() being ambiguous. Note that the constructor is explicit so

问题 How do I create a type using the Python C API that inherits from multiple other types? The Python documentation includes an example of a type that inherits from one other type, but there is no example or mention of multiple inheritance I could find. 回答1: The C API does not support multiple inheritance. You'd have to call PyType_Type yourself, simulating a standard Python class statement. This is documented under the C API section on specifying a base type for an extension type: PyTypeObject*

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: Why do multiple-inherited functions with same name but different signatures not get treated as overloaded functions? This fails to compile in the indicated place with g++ 4.6.1: enum Ea { Ea0 }; enum Eb { Eb0 }; struct Sa { void operator()(Ea) {} }; struct Sb { void operator()(Eb) {} }; struct Sbroken : Sa, Sb {}; struct Sworks { void operator()(Ea) {} void operator()(Eb) {} }; int main() { Sworks()(Ea0);