Question

I am implementing a class that in the style of the LINQ libraries has an overload for a custom IComparer. (e.g. OrderBy: OrderBy<TSource, TKey>(IEnumerable<TSource>, Func<TSource, TKey>) and OrderBy<TSource, TKey>(IEnumerable<TSource>, Func<TSource, TKey>, IComparer<TKey>)).

I would like to implement the 2-argument overload in terms of the 1-argument overload. Something like the following:

T Method<T>(IEnumerable<T> collection, IComparer<T> comparer)
{
    // Do something that returns a T
}

T Method<T>(IEnumerable<T> collection) where T: IComparable<T>
{
    IComparer<T> comparer = /*what goes here?*/;
    return Method(collection, comparer);
}

In this respect, the question boils down to asking, how do I obtain an instance of IComparer for a type that implements IComparable?

Answer 1

You are looking for Comparer<T>.Default.