What is the “base class” for C# numeric value types?

Question

Say I want to have a method that takes any kind of number, is there a base class (or some other concept) that I can use?

As far as I know I have to make overloads f

Answer 1

What I do:

 public interface INumeric
 {
     T Zero { get; }
     T One { get; }
     T MaxValue { get; }
     T MinValue { get; }
     T Add(T a, T b);
     // T Substract(....
     // T Mult...
 }  

 public struct Numeric: 
     INumeric, 
     INumeric,
     INumeric,
     INumeric,
     // INumeric
 {
     int INumeric.Zero => 0;
     int INumeric.One => 1;
     int INumeric.MinValue => int.MinValue;
     int INumeric.MaxValue => int.MaxValue;
     int INumeric.Add(int x, int y) => x + y;

     // other implementations...
 }

Now, you can use it in a method:

bool IsZero(TNum ops, T number) 
   where TNum : INumeric
{
   return number == ops.Zero;      
}

or extension method

 public static bool IsZero(this TNum ops, T number)
      where TNum : INumeric
 {
      return number == ops.Zero;
 }

and in your code:

 ...
 var n = new Numeric(); // can be an static prop

 Console.WriteLine(IsZero(n, 5)); // false
 Console.WriteLine(IsZero(n, 0f)); // true
 Console.WriteLine(IsZero(n, "0")); // compiler error

or, with extension method:

 Console.WriteLine(n.IsZero(5));  // false
 Console.WriteLine(n.IsZero(0f)); // true
 Console.WriteLine(n.IsZero("0")); // compiler error