You need to add the Sprite to a Layer or something.
std::vector <CCSprite*> _sprites;
_sprites.reserve(10);
for (int i=0;i < 5; i++)
{
CCSprite* foo = cocos2d::CCSprite::create("sprites.png");
_sprites.push_back(foo); // <- store your sprites to do stuff to them later.
addChild(foo, 1); //<-- this is adding the child.
}