Question

我试图尽可能避免切换，我想出了这个（不是）解决方案。你知道是否有办法做某事：

enum MyEnum { A, B, C, D, E, F, SIZE=F};

typedef void (*GenericFunction)(int);

template<class EnumType>
struct MyEnumTraits
{
  template<EnumType code, Args... args>
  void doStuff(args);
};

template<class EnumType, int size, MyEnumTrait>
struct Switcher
{
  Switcher()
  {
     //Do compile time initialization by populating functions_
     //doing something like: (pseudo c++ code following)

      // template metaprogramming iteration of the EnumType values: 
      //from the first to the last one (size)

     for(int i; i<size;i++)
       functions_[i] = (GenericFunction) MyEnumTrait::MyFunctionType; //
  }

  GenericFunction functions_[size];
};

template<>
struct MyEnumTraits<MyEnum>
{
  template<>
  void doStuff<A>(int a)
  {
     // do something
  }
};

template<>
struct MyEnumTraits<MyEnum>
{
  void doStuff<B,int,int>(int a, int b)
  {
    // do something else
  }
};

template<>
struct MyEnumTraits<MyEnum>
{
  template<>
  void doStuff<C, std::string>(const std::string& myString)
  {
    // do something else..
  }
};

int main()
{

  Switcher<MyEnum, SIZE> switcher;
  // Next calls will not work because I need a cast.. 
  //is there any magic I can do to avoid the cast?

  // these may work
  switcher.functions_[A](3);
  switcher.functions_[B](1,2);
  switcher.functions_[C]("bla bla");

  // this is probably impossible to do... isn't it?
  MyEnum en = /* get it from cin */;
  switcher.functions_[en](1,2,3);
}

我为糟糕的缩进道歉，我会尝试尽快重构代码

[编辑]更改了代码的最后3行

如何进行枚举编译时迭代

0 个答案: