How are addresses being used to find position?

Asked May 01 '21 at 05:56

Active May 01 '21 at 06:17

Viewed 31 times

When I cout &elem or &list separately I get their addresses. How does subtracting them give you an int?

vector<int> list;
for(auto& elem:list) { 
int i = elem;
int pos = &elem-&list[0]; // pos contains the position in the vector 

// also a &-operator overload proof alternative (thanks to ildjarn) :
// int pos = addressof(elem)-addressof(list[0]); 

}

edited May 01 '21 at 06:17

asked May 01 '21 at 05:56

user2419731

1

`for (auto& i : key) cout << i.at(0);`? – MikeCAT May 01 '21 at 05:58
that just gives the first value of i – user2419731 May 01 '21 at 06:06
@user2419731, please share what you need as output. That is not clear. Above comment should give you want you want. – mangupt May 01 '21 at 06:07
my apologies, I thought it was clear. im looking to get output from 0-7. – user2419731 May 01 '21 at 06:08
`for (size_t i = 0; i < key.size(); i++) { cout << i ; }` – mangupt May 01 '21 at 06:13

How are addresses being used to find position?

0 Answers0