Question

Is there a way to invoke a generic function with a type known only at run time?

I’m trying to do something like:

    static  void bar()
    {
        object b = 6;
        string c = foo<typeof(b)>();
    }

    static  string foo<T>()
    {
       return typeof (T).Name;
    }

Basically I want to decide on the type parameter only at run time, but the function I’m calling depends on the type parameter.

Also I know this can be done with reflections… but it’s not the nicest solution to the problem…

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I’m sort of looking for dynamic features in C#…

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I’m writhing a bridge between two classes the first one is basically a big tree with different types of of objects (composite by interface) the other is a sort of a “super visitor”.
the supper visitor accepts key-value dictioneries that map types to object it looks like:
dic.Add(object value)

and T is not necessarily the type of the value… a lot of times it isn’t…
I know it’s written poorly, but i can’t fix it…
I can work around it, but only at runtime…

I already did it with reflections, but if there’s a better way to do it without them i would be happy to learn…

Thank you

Answer 1

This is a bit of a hack but you can get dynamic to do the reflection work for you by something like,

class Program
{
    static void Main(string[] args)
    {
        var b = 6;
        var t = (dynamic)new T();
        var n = t.Foo(b);
    }

    class T
    {
        public string Foo<T>(T a)
        {
            return typeof(T).Name;
        }
    }
}

Here the dynamic call will extract the type of b and use it as a type parameter for Foo().