Let's say I have the following const vector of pointer :
const std::vector<Component*> components; and I want to iterate through it and only calling a method on one element of this vector. Is it correct to do :
for (const auto& item : components) { method(item); } What is the difference with using :
for (auto item : components) { method(item); } with :
void method(Components* component); Is it correct to do
It depends on you.
For the 1st case, the type of item will be Component* const&, which is a reference bound to the element of the vector.
For the 2nd case, the type of item will be Component*, which (i.e. the pointer itself) is copied from the the element of the vector.
The parameter type of method is Component*, means passing the pointer by value/copy, then there's no actual difference between the 2 cases. And for pointer (as built-in type), just auto item : components is fine here.
item to be?for (auto& item : components) is enough and if one day my vector becomes a vector of Components (and not Components*), it will still works... right ?auto item : ... seems fine. auto& makes item a reference to the element, if you change it point to another thing, the element is changed too. If that's what you want you should use reference.