CODEWITHSUNDEEP
c#.net
Ovy.Istrate
Ovy.Istrate

Reputation: 504

How to define a Generic Collection Type of a Generic Type

I have the following class with the following extension method:

public static class CollectionsExtensions
{
    public static List<List<T>> Split<T>(this List<T> collection, int size)
    {   
        if (size == 0)
            throw new ArgumentException();

        var chunks = new List<List<T>>();
        var chunkCount = collection.Count / size;

        if (collection.Count % size > 0)
            chunkCount++;

        for (var i = 0; i < chunkCount; i++)
            chunks.Add(collection.Skip(i * size).Take(size).ToList());

        return chunks;
    }
}

I use a code analyzer which helps pointing out code smells and potential flaws, and for this one I have a suggestion to switch the return type of the method to be of generic type. I've tried changing the signature of the method to be something like this:

public static List<U<T>> Split<U,T>(this U<T> collection, int size) where U : IEnumerable<T>

But unfortunately it's not working, so, is there a proper way to define a class with a method that can return a List of U collections of type T ?

Upvotes: 1

Views: 87

Answers (2)

Ehsan Sajjad
Ehsan Sajjad

Reputation: 62488

When you are saying this: 

where U : IEnumerable<T>

That means that U will be a List<T> or some type which is inheriting from IEnumerable<T>, so that means your method's return type can be List<U> in that case, which will be the same like List<IEnumerable<T>> or List<List<T>>.

At the time of using the method the compiler will resolve the type parameters U to inject IEnumerable<T> where T will be the type provided.

Upvotes: 4

Bugfish
Bugfish

Reputation: 1730

You could write it like that:

public static List<U> Split<U, T>(this U collection, int size) where U : IEnumerable<T>

Upvotes: 2

Related Questions