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Generics Challage: Assert Return Types Matches
I feel that I gave it too much already, and I am giving up. A workaround is too good for this issue.
Given the following class defination:
public class Dog
{
public static MethodInfo LastCall = null;
public class BarkInvocation<T>
{
public T Bark()
{
LastCall = (MethodInfo)MethodInfo.GetCurrentMethod();
return default(T);
}
}
public T Bark<T>()
{
return new BarkInvocation<T>().Bark();
}
}
Can you make this print true?
public class Program
{
[STAThread]
static void Main(string[] args)
{
Dog d = new Dog();
d.Bark<IList<string>>();
Type returnType = Dog.LastCall.ReturnType;
List<string> strings = new List<string>();
Console.WriteLine(returnType.IsInstanceOfType(strings));
}
}
Comments
IList<string> is not an instance of List<string>, isn't it?
Wow, this is a good one. The method's return type will always be T, because at runtime it's resolved from System.RuntimeType.
The only way I'd know of is to also have a LastReturnType static field on Dog and set it to typeof(T) in BarkInvocation<T>.Bark()... which I'm sure there's a reason you're not already doing (I know I hate to add what I feel are more fields that aren't required).
@Weex,
If you do a test as I mention above, you'll see that just calling
typeof(IList<string>).IsInstanceOf(new List<string>());
will return true.
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