Is it possible to use generic constraints based on attributes rather than types?

Question

I'm trying to write a class that will be in charge of persisting application options. Since the options need to be persisted the values that I'm sent must be serialisable.

Initially I thought I've be able to write a method with a signature like this:

Public Sub SaveOption(Of T As ISerializable)(ByVal id As String, ByVal value As T)

or if you prefer C#:

public void SaveOption<T>(string id, T value) where T : ISerializable  

In principle this would be fine, but what about types that have the <Serializable> attribute? The most notable example of this is System.String, it does not implement ISerializable, but clearly it is a type that I should be able to save.

So, is there a way that I can restrict which types are allowed into a method at compiletime, based on their attributes?

Answer 1

You could have overloads for the other types - taking your string example:

public void SaveOption(string id, string value)

However; serializability is... tricky; I expect you're going to have to check this at runtime.