Generic repository - IRepository<T> or IRepository

Question

I have seen two different approaches for creating generic repositories. What are differences between those two approaches (pros and cons) ? Please diregard difference in the methods because I am interested in difference between

 public interface IRepository<T> where T : class 

and

 public interface IRepository : IDisposable 

Is there any difference in functionality, flexibility, unit testing ... ? What will I get or lose ?
Is there any difference how they are registered in Dependency Injection frameworks ?

Option 1

 public interface IRepository<T> where T : class  {        T Get(object id);        void Attach(T entity);        IQueryable<T> GetAll();        void Insert(T entity);        void Delete(T entity);        void SubmitChanges();  } 

Option 2

 public interface IRepository : IDisposable     {         IQueryable<T> GetAll<T>();         void Delete<T>(T entity);         void Add<T>(T entity);         void SaveChanges();         bool IsDisposed();     } 

Answer 1

The biggest difference is that IRepository<T> is bound to a single type while an IRepository is potentially bound to multiple types. Which one is appropriate is highly dependent upon your particular scenario.

Generally speaking I find IRepository<T> to be more useful. At the time of use it's extremely clear what the contents of IRepository<T> are (T). On the other hand it's not clear from a given IRepository what is contained inside of it.

In cases where I have to store multiple types of objects, I usually create a map of IRepository<T> instances. For instance: Dictionary<T,IRepository<T>>.