How to do virtual function with enum?

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Hi
I'm trying to using enum passing the parameter to virtual function. I want to practice the Strategy mode of design pattern. Here is my code(example) ,which should print "Hello".(C++), I ran but error, Error message:

undefined reference to `test(Enum)'

What I have tried:

I don't know how to fix the code.

Here is my code:

class Base
{
  public:
  virtual void show() = 0;
};

class child1 : public Base
{
  public:
  void show(){
      cout<<"Hello"<<endl;
  };
};

enum Enum {
    child1,child2,
};



int main() {
    Base* test(Enum);
auto the_test =test(child1);
the_test->show();
    return 0;
}

Posted 4-Dec-20 22:57pm

林小瑋

Updated 4-Dec-20 23:22pm

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Richard MacCutchan · Answer 1 · 2020-12-04T23:22:00

Solution 1

Just about everything is wrong with your code. You are trying to instantiate an abstract class. You are trying to create an instance by passing a class name to a parameterless constructor. You are using the same names for a class, and an enumeration value. I suggest you go back to the C++ documentation and study the section on classes again.

Posted 4-Dec-20 23:22pm

Richard MacCutchan

Comments

Rick York 5-Dec-20 13:48pm

A trifecta of errors.