using System;

​

public class Program

{

    public static void Main()

    {

        long firstOperand = 10;

​

        float floatOperand = 45.5f;

        double doubleOperand = 50.5;

        decimal decimalOperand = 10.5m;

        nuint nuintOperand = 60;

        ulong ulongOperand = 40;

​

        // Explicit conversion (cast) required

        long resultLong1 = firstOperand + (long)doubleOperand;   // long = long + (cast of double to transform it into long) 

        long resultLong2 = firstOperand + (long)floatOperand;    // long = long + (cast of float to transform it into long)

        long resultLong3 = firstOperand + (long)decimalOperand;  // long = long + (cast of decimal to transform it into long)

        long resultLong4 = firstOperand + (long)nuintOperand;    // long = long + (cast of nuint to transform it into long)

        long resultLong5 = firstOperand + (long)ulongOperand;    // long = long + (cast of ulong to transform it into long)

        //long resultEx1 = firstOperand + doubleOperand;   // long = long + double    NOT OK

        //long resultEx2 = firstOperand + floatOperand;    // long = long + float     NOT OK

        //long resultEx3 = firstOperand + decimalOperand;  // long = long + decimal   NOT OK

        //long resultEx4 = firstOperand + nuintOperand;      // long = long + nuint   NOT OK

        //long resultEx5 = firstOperand + ulongOperand;      // long = long + ulong   NOT OK

        var resultEx6 = firstOperand + doubleOperand;      // double = long + double     OK

        var resultEx7 = firstOperand + floatOperand;       // float = long + float       OK

        var resultEx8 = firstOperand + decimalOperand;     // decimal = long + decimal   OK

        //var resultEx9 = firstOperand + nuintOperand;       // ??? = long + nuint       NOT OK

        //var resultEx10 = firstOperand + ulongOperand;      // ??? = long + ulong       NOT OK

    }

}