How to create a generic C# method that can return either double or decimal?

Question

I have a method like this:

private static double ComputePercentage(ushort level, ushort capacity)
{
      double percentage;
      if(capacity == 1)
        percentage = 1;

      // do calculations...
      return percentage;
}

Is it possible to make it of a generic type like "type T" where it can return either decimal or double, depending on the type of method expected (or the type put into the function?)

I tried something like this and I couldn't get it to work, because I cannot assign a number like "1" to a generic type. I also tried using the "where T :" after ushort capacity) but I still couldn't figure it out.

private static T ComputePercentage<T>(ushort level, ushort capacity)
{
      T percentage;
      if(capacity == 1)
        percentage = 1; // error here

      // do calculations...
      return percentage;
}

Is this even possible? I wasn't sure, but I thought this post might suggest that what I'm trying to do is just plain impossible.

---

EDIT

Thanks to all who responded, many good answers. As Tomas pointed out, this is probably best done in two separate methods. As pointed out by both TreDubZedd and TcKs, the best way to get the functionality I would want is to use an implicit conversion that could return either a double or decimal implicitly.

Answer 1

In fact, you don't need generics but overloading. However you need overloading by return value's type which is supported by IL but is not supported by C#.

I prefere two methods for every return's value type:

static double  ComputePercentageDouble  (ushort level, ushort capacity)
static decimal ComputePercentageDecimal (ushort level, ushort capacity)

The alternative can be custome type with implicit cast operators:

decimal decimalPercentage = ComputePercentage( 1, 2 );
double  doublePercentage  = ComputePercentage( 1, 2 );

static DoubleDecimal ComputePercentage( ushort level, ushort capacity ) {
    DoubleDecimal percentage = default( DoubleDecimal );
    if ( capacity == 1 )
        percentage.Number = 1; // error here

    // do calculations...
    return percentage;
}


public struct DoubleDecimal {
    public decimal Number;

    public static implicit operator decimal( DoubleDecimal value ) {
        return value.Number;
    }
    public static implicit operator double( DoubleDecimal value ) {
        return (double)value.Number;
    }
}

Answer 2

You might be able to use implicit conversion: http://msdn.microsoft.com/en-us/library/zk2z37d3.aspx