ChallengeDynamically dynamic

time to read 3 min | 538 words

Can you figure out a way to write the following code without using a try/catch?

class Program
{
    static void Main(string[] args)
    {
        dynamic e = new ExpandoObject();
        e.Name = "Ayende";

        Console.WriteLine(HasProperty("Name", e));
        Console.WriteLine(HasProperty("Id", e));
    }

    private static bool HasProperty(string name, IDynamicMetaObjectProvider dyn)
    {
        try
        {
            var callSite =
                CallSite<Func<CallSite, object, object>>.Create(
                    Binder.GetMember(CSharpBinderFlags.None, name, typeof (Program),
                                     new[]
                                     {
                                         CSharpArgumentInfo.Create(
                                             CSharpArgumentInfoFlags.None, null)
                                     }));
            callSite.Target(callSite, dyn);
            return true;
        }
        catch (RuntimeBinderException)
        {

            return false;
        }
    }
}

The HasProperty method should accept any IDynamicMetaObjectProvider implementation, not just ExpandoObject.

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