Workaround for inability to create C# generic constraints for the presence of a constructor that takes parameters... i.e. Foo<T>(string name) where T: new(string)

GenericConstructorHelper.cs

public Func<T1, TResult> CompileConstructor<T1, TResult>()
{
   var type1 = typeof(T1);
   var parameter1 = Expression.Parameter(type1);
   var constructor = typeof(TResult).GetConstructor(new Type[] { type1 });
   var body = Expression.New(constructor, parameter1);
   var lambda = Expression.Lambda<Func<T1, TResult>>(body, parameter1);
   var method = lambda.Compile();
   return method;
}
// obviously you could do some caching here...
public TResult New<T1, TResult>(T1 t1)
{
   return GetConstructor<T1, TResult>()(t1);
}
// example usage: i.e. a generic method that calls an unnamed type constructor that takes a parameter (in this case a string).
public TResult CreateNode<TResult>(string name) where TResult: INode
{
   return New<TResult,string>(name);
}

@adjames, it seems that the statement return New<TResult,string>(name); should have the generics the other way round:

return New<string, TResult>(name);