Allowing only Options objects in OpenList constructors means lots of code changes 
and lots of additional code, since for each constructor call we have to create 
and populate an Options object. Also, there's currently no real reason why we 
need to require Options objects. Therefore, I'm closing this issue for now.

That changed as we now pass the local open list as an argument to the search. 
And we only need the options being available in the search engine to be able to 
create a local search and there the options are used.
But since I don't create new open lists any more it is not important there 
anymore.

I think this is still important since currently we can only use eager() and 
lazy() for local exploration searches (issue466) and neither eager_greedy() nor 
lazy_greedy() since these create open lists without passing any Options objects.

With the latest changes to issue466 this is of no concern regarding my im
implementation.

But it still could be a possibility to simplify the construction of open lists.

In both cases 
StandardScalarOpenList<OpenListEntryLazy>(evals[0],false); is used and no o
options are passed to the open list.
That's the reason we have to maintain this constructor besides StandardScalarOpenList
StandardScalarOpenList(const Options &opts);

In my implementation for local search I store a copy of the options inside the op
open list, to be able to create a new instance of the open list based on the sa
same options. But I can also modify those options before I create a new in
instance.
But if the open list was created without options at all this will fail.
Tho I think it would make sense, not only for my branch but also in general, to 
change the way the open lists are created there.

What is exactly the issue here? What do we currently have to do what we want to
avoid?

Some searches still don't use the options class that results in the need of 
additional constructors for OpenLists.
Also issue466 is heavily based on the use of options to create new open lists 
with the same settings, which is impossible in some cases due to the creation 
of the open_lists without the Options class.