Wich IEnumerable To a List way is better?
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I am wondering about the following fact. I have a data repository that returns all my data of IEnumerable<Customer>. In my bussines logic sometimes i need lists so i can add stuff for example. when i retrieve the IEnumerable<Customer> i have 2 options to get a list from it. 1.Either using the Linq extension method .ToList() or cast it (i think its not a conversion) like this (List<Customer>)IEnumerable<Customer>. Must mention that i dont use the list for iterations so i dont need a new copy of my enumeration each time. In this case is it true that in my simple case i must use the cast method instead of .ToList(wich creates a new copy) ?

    List<Customer> customers = (List<Customers>)DataSource.GetCustomers(); // use simple cast?

    List<Customer> customers = DataSource.GetCustomers().ToList(); // or if i use this i get a bit of performance loss for nothing?