Question

How does in the following example XElement internally store an object implementing IEnumerable<A>? Is ToString called on each of A type objects stored in this collection and the resulting value is treated as a string content ( as aXText) and is thus appended to “someString” value, or …?

class Program
{
    static void Main(string[] args)
    {
        A[]  = new A[10];
        for (int i = 0; i < 10; i++)
            a[i] = new A();

        XElement element = new XElement("XMLElement", "someString", a);
        Console.WriteLine(element);
    }
}

class A { }

thank you

Answer 1

See http://msdn.microsoft.com/en-us/library/bb943882.aspx for an explanation what you can pass in as contents of XDocuments and XElements with the constructors and methods like Add.
For your A instances you are right that ToString() is called and that each result of that called is appended to form the Value of a single XText child node of the “XMLElement” XElement you create.