Question

I’m writing a pluralization framework using .NET for Windows Store apps. For a custom formatter string Format(string format, params object[] args), I have the following code:

public static bool IsExactlyOne(object n)
{
    if (n is Int16)
    {
        return (Int16)n == 1;
    }
    if (n is int) // Int32
    {
        return (int)n == 1;
    }
    if (n is long) // Int64
    {
        return (long)n == 1L;
    }
    if (n is UInt16)
    {
        return (UInt16)n == 1U;
    }
    if (n is uint) // UInt32
    {
        return (uint)n == 1U;
    }
    if (n is ulong) // UInt64
    {
        return (ulong)n == 1UL;
    }
    if (n is byte)
    {
        return (byte)n == 1;
    }
    if (n is sbyte)
    {
        return (sbyte)n == 1;
    }
    if (n is float)
    {
        return (float)n == 1.0F;
    }
    if (n is double)
    {
        return (double)n == 1.0D;
    }
    if (n is decimal)
    {
        return (decimal)n == 1.0M;
    }

    throw new ArgumentException("Unsupported type");
}

As you see, it’s pretty verbose. Is there some way to simplify this? Please note: IConvertible is not available for Windows Store apps.

Answer 1

How about using Dictionary to avoid if:

var dic = new Dictionary<Type, Func<object, bool>>()
                    {
                        {typeof(Int16), a => (Int16)a == 1},
                        {typeof(int), a => (int)a == 1},
                         ....
                    };

return dic[n.GetType()](n);

Or use dynamic:

public static bool IsExactlyOne(dynamic n)
{
    return n == 1;
}