What's with the warning?

Question

I get a warning when running this code.
https://code.sololearn.com/c842MPT0CN64/?ref=app

Answer 1

for(unsigned int i=0; i<Shelf.size(); i++) {
std::cout << Shelf[i]->Name << '\n';

Answer 2

Seems you got it figured out, I didn't get any warning when running the code.

Answer 3

Ipang Yea, thanks though. Lol