@TomFischer I finally got the random tests running to find out whether std::remove_copy followed by std::swap is faster or slower than std::remove followed by std::vector::erase:
Second option is slightly faster (3% total runtime) with cleaner code.
(Most time ca. 50% of was spent in BaseLib::Quicksort.)

I have inserted 10^6 points andca. 12000 unique points remained in the container.

I'll make a pull request this week.