Sorting Sets using std::sort
c++, set, stl
Solution
You cannot resort a `set`, how it sorts is part of the type of the particular `set`. A given `set` has a fixed set order that cannot be changed.
You could create a new `set` with the same data relatively easily. Just create a new `set` that sorts based on the new criteria.
If you want to use the two `set`s in the same code, you'll have to abstract the access to the underlying `set`.
Now, if you are doing rare reads and modifications, using a `vector` that you sort manually is often a better idea. You can remove duplicates by using the `std::unique`-`erase` idiom.
Problem
I would like to know if we can sort a pre created set. When I first create the set s_p2, I sort using a different element point.getLength(). but after user input i would like to sort the items according to the x value point.getX(). How i do this ? It seems like set container does not have a sort function. And i am advised to use vector. But sets are able to store unique elements only. Q1: How can i sort a set depending on the criteria Q2: If set is unable to do this than which STL container is the best choice and how can i sort the elements in the container.