Question

Let T be a generic type. I would like to do something like this:

T x = default(T);
if (T has standard constructor)
  x = new T();

Of course, one could restrict T to types having such a constructor, but I do not want ot exclude value types.

How can you do that?

Answer 1

You’ll have to use reflection:

ConstructorInfo ci = typeof(T).GetConstructor(Type.EmptyTypes);
if (ci != null)
    x = (T)ci.Invoke(null);

You can also use Activator.CreateInstance<T>(), but that will throw an exception if the constructor doesn’t exist.