std::advance

• modifies its argument
• returns nothing
• works on input iterators or better (or bi-directional iterators if a negative distance is given)

std::next

• leaves its argument unmodified
• returns a copy of the argument, advanced by the specified amount
• works on forward iterators or better (or bi-directional iterators if a negative distance is given))

https://*.com/questions/15017065/whats-the-difference-between-stdadvance-and-stdnext