Best way to test if a generic type is a string? (C#)

Question

I have a generic class that should allow any type, primitive or otherwise. The only problem with this is using default(T). When you call default on a value type or a string, it initializes it to a reasonable value (such as empty string). When you call default(T) on an object, it returns null. For various reasons we need to ensure that if it is not a primitive type, then we will have a default instance of the type, not null. Here is attempt 1:

T createDefault() {     if(typeof(T).IsValueType)     {         return default(T);     }     else     {         return Activator.CreateInstance<T>();     } } 

Problem - string is not a value type, but it does not have a parameterless constructor. So, the current solution is:

T createDefault() {     if(typeof(T).IsValueType || typeof(T).FullName == "System.String")     {         return default(T);     }     else     {         return Activator.CreateInstance<T>();     } } 

But this feels like a kludge. Is there a nicer way to handle the string case?

Answer 1

Keep in mind that default(string) is null, not string.Empty. You may want a special case in your code:

if (typeof(T) == typeof(String)) return (T)(object)String.Empty; 

Answer 2

if (typeof(T).IsValueType || typeof(T) == typeof(String)) {      return default(T); } else {      return Activator.CreateInstance<T>(); } 

Untested, but the first thing that came to mind.