C#: check null arguments in an elegant way

Guard.cs

// Copied from:
// http://www.minddriven.de/index.php/technology/dot-net/c-sharp/efficient-expression-values

public static class Guard
{
    public static void AssertNotNull<T>(Expression<Func<T>> selector)
    {
        var memberSelector = (MemberExpression)selector.Body;
        var constantSelector = (ConstantExpression)memberSelector.Expression;
        var value = ((FieldInfo)memberSelector.Member).GetValue(constantSelector.Value);

        if (value == null)
        {
            var name = ((MemberExpression)selector.Body).Member.Name;
            throw new ArgumentNullException(name);
        }
    }
}