Question

If I do this, I enumerate over all types in my program:

List<SerializableAttribute> attributes=new List<SerializableAttribute>() ;
foreach (Assembly assembly in AppDomain.CurrentDomain.GetAssemblies())
{
    foreach (Type type in assembly.GetTypes())
    {
        attributes.AddRange(
                            type.GetCustomAttributes(false)
                            .OfType<SerializableAttribute>()
                            .ToList());
    }
}

Is metadata that comes with a .NET dll indexed to allow me to do something like:

List<SerializableAttribute> attributes = typeof(SerializableAttribute)
                                         .GetClassesIAmDefinedOn();

Is there another option that I’m not considering?

(SerializableAttribute is just an example)

Answer 1

The most efficient thing to use here generally is Attribute.IsDefined(...), although in the specific case of [Serializable], type.IsSerializable is faster (it isn’t actually stored as an attribute in this one case – it has special handling in the compiler, mapping to a CLI flag).