How to use the dynamic
when specifying generic type arguments in C#?
I am reading the CLR via C# book. And I come across the following paragraph:
It is also possible to use dynamic when specifying generic type arguments to a generic class (reference type), a structure (value type), an interface, a delegate, or a method. When you do this, the compiler converts dynamic to Object and applies DynamicAttribute to the various pieces of metadata where it makes sense. Note that the generic code that you are using has already been compiled and will consider the type to be Object; no dynamic dispatch will be performed because the compiler did not produce any payload code in the generic code.
As far as I understand this excerpt tells that I can use the dynamic
as a type argument in (e.g.) a class definition. But after trying this out I come to a conclusion that it is no different from using any other placeholder in the type argument. So, I doubt that my understanding is correct.
using System;
namespace myprogram
{
class A<dynamic> {
public dynamic a;
}
class B {
public Int32 b;
}
class C<T> {
public T c;
}
class Program {
static void Main(string[] args) {
//Cannot implicitly convert type 'string' to 'myprogram.B' [Console.NET]csharp(CS0029)
//A<B> a = new A<B> {a = "foo"};
//Cannot implicitly convert type 'string' to 'myprogram.B' [Console.NET]csharp(CS0029)
//C<B> c = new C<B> {c = "foo"};
//as you can see it does not matter if I use the T or dynamic, the effect is the same
//so, what is the use of using the dynamic in the class definition?
}
}
}