C ++模板类/类型，可在最大值和最小值之间进行选择

Question

I am trying to write a templated class.

template <<typename T>>
myclass {
  // ...
}

I want T to be such that if I instantiate myclass obj<T> with a proper T , the class should be able to choose between min or max of two numbers. ie myclass is instantiated with min or max as the case maybe.

I dont mind using std::less/std::more/std::max/std::min or any of the inbuilt functor objects.

However, I would prefer not to use enums in the constructor and then depending on the enum value, call min or max routines. I want the code to be a little cleaner. Any ideas? Is it possible to do this at all in C++

Answer 1

This isn't a big deal. Consider the following:

template<typename T> class MyClass {
public:
    int foo(int a, int b) const {
        return T()(a, b);
    }
};

Now if T is a type whose operator() returns the maximum of it's two arguments, then you will return the maximum, and ditto for any other binary algorithm you wish to apply.

Answer 2

[EDIT] I believe that I didn't fully get the point of your question and that @DeadMG's answer is in fact what you are looking for.

The template below allows you to instantiate a class which given T, MIN, MAX can provide some number X between MIN and MAX between T.

template<int T, int MIN, int MAX, int X = MIN + T/(MAX - MIN)>
class MyClass
{
  int foo() const
  {
    return X;
  }
};