Thanks @quantage ! Will take a look at your solution...
Actually, in the description (and the note at the end) it is said that your C++ function should return ALL
possible solutions (it's just a func prototype), but for this kata all problems have EXACTLY ONE solution.
We could go 3 ways:
a- keep it like it is (and may be make the description/notes/hints) more clear,
b- add some cases with multiple solutions (with lexico sorting at the end, would be easy to test)
c- add some 'no solution' cases (but that was not my first intention.

Note: it was @@##++_ tricky to generate problems with exactly one solution, though.....