InvalidCastException: Object must implement IConvertible when using Get method with interface as type

[alexanderar]

I have a pretty simple scenario:

1. Repo class that returns a IList<SomeDto> items

public class Repo
{
      public IList<SomeDto> Get()
      {
           return new List<SomeDto>();
      }
}

1. service class that has a ICacheManager and uses it to cache the repo result:

   public class Service
   {
         private ICacheManager<object> _cacheManager;
   
         private Repo _repo;
   
         public Service(ICacheManager<object> cacheManager, Repo repo)
         {
               this._cacheManager = cacheManager;
               this._repo = repo;
         }
   
         public  IList<SomeDto> Get()
         {
                var items =  this._cacheManager.Get< IList<SomeDto>>("items");
                if(items == null)
                {
                      items = this._repo.Get();
                      this._cacheManager.Add("items",items);
                 }
                 return items;
         }
   }
   

   After cache has been instantiated with items
   this._cacheManager.Get< IList<SomeDto>>("items") throws an InvalidCastException: Object must implement IConvertible, while if I change it to
   this._cacheManager.Get<List<SomeDto>>("items") -- notice List instead of IList -- the cache works as expected.

   My question is whether it is possible to use interfaces/base classes to retrieve items from cache.

   Thanks in addvance

   Alex

[MichaCo]

yup can be changed so that the converting Get method supports that