C# Error CS0216 – The operator ‘operator’ requires a matching operator ‘missing_operator’ to also be defined

C# Compiler Error

CS0216 – The operator ‘operator’ requires a matching operator ‘missing_operator’ to also be defined

Reason for the Error

You will receive this error in C# when you are working with the user defined operators and missed defining the required operator.

For example, when you define a user defined operator for true operator, you’ll need to define the false operator as well. The same applies for == and != operators.

For example, try to compile the below code snippet.

namespace DeveloperPubNamespace
{   
    class Program
    {
        public static bool operator true(Program obj)  
        {
            return true;
        }

        static void Main()
        {
        
        }
    }
}

This program will result with the error code CS0216 because we have defined the user defined true operator but missed the false operator.

Error CS0216 The operator ‘Program.operator true(Program)’ requires a matching operator ‘false’ to also be defined ConsoleApp3 C:\Users\SenthilBalu\source\repos\ConsoleApp3\ConsoleApp3\Program.cs 5 Active

Solution

When you are working with the user defined operators in C#, you’ll need to ensure that you define the required operators. You can fix the error in your C# program by defining the missing operator (Eg : false in the above program) as demonstrated in the below code snippet.

namespace DeveloperPubNamespace
{   
    class Program
    {
        public static bool operator true(Program obj)  
        {
            return true;
        }
        public static bool operator false(Program obj)
        {
            return false;
        }
        static void Main()
        {
        
        }
    }
}