Code inspection: Replace with '.OfType<T>()'

This inspection identifies LINQ Where() calls that filter elements by type using an is expression, followed by a Cast<T>() call. These combined operations can be replaced with a single call to OfType<T>(), which is more concise and readable.

            
    public void Sample(object[] objects)
    {
        _ = objects.Where(a => a is List<string?>).Cast<List<string>>();
    }

            
    public void Sample(object[] objects)
    {
        _ = objects.OfType<List<string>>();
    }

The quick-fix replaces the Where().Cast<T>() chain with a single OfType<T>() call.

11 March 2026