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

Calculating dependencies ... done!
Dependency resolution took 1.01 s (backtrack: 0/20).

[ebuild  N     ] dev-libs/utfcpp-4.0.6::gentoo  USE="-test" 34 KiB
[ebuild  N     ] media-libs/taglib-2.3.2:0/2::gentoo  USE="-doc -examples -test" 1714 KiB
[ebuild  N     ] media-sound/mp3unicode-1.2.1-r1::gentoo  100 KiB

Total: 3 packages (3 new), Size of downloads: 1846 KiB