These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 0.98 s (backtrack: 0/20).

[ebuild  N     ] sci-libs/nanoflann-1.7.1::gentoo  USE="-examples -test" 511 KiB

Total: 1 package (1 new), Size of downloads: 511 KiB