C# Error CS0567 – Conversion, equality, or inequality operators declared in interfaces must be abstract or virtual

C# Error

CS0567 – Conversion, equality, or inequality operators declared in interfaces must be abstract or virtual

Reason for the Error & Solution

Interfaces cannot contain operators

Operators are not permitted in definitions.

The following sample generates CS0567:

// CS0567.cs  
interface IA  
{  
   int operator +(int aa, int bb);   // CS0567  
}  
  
class Sample  
{  
   public static void Main()
   {  
   }  
}