Printing a pair out as a string

Asked Oct 26 '17 at 18:06

Active Feb 18 '19 at 14:37

Viewed 2,529 times

I am trying to print out a string from a const pair I declared

using Collatz = pair<long, vector<long> >;

However, in this function, it allows me to print the first value with no problems. When I want to print the second value, it makes me add the & symbol to it which then prints out the address. How do I get around this so I can print out the actual value.

string Collatz_to_string(const Collatz &p) {
ostringstream oss;
oss << p.first << "," << p.second;
return oss.str();
}

Candidate function not viable: no known conversion from 'const std::__1::vector >' to 'const void *' for 1st argument; take the address of the argument with &

edited Feb 18 '19 at 14:37

Brian Tompsett - 汤莱恩

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asked Oct 26 '17 at 18:06

vApp

2

there is no overload for `operator<<` that takes a vector. you have to write your own – 463035818_is_not_an_ai Oct 26 '17 at 18:07
Yeah i fixed it, I just converted the vector to a string, and then printed it out. – vApp Oct 26 '17 at 18:08
the dupe is asking for `printf` but the answer is exhaustively discussing using `operator<<` – 463035818_is_not_an_ai Oct 26 '17 at 18:09
btw not sure what you want to have, but you dont need the detour via a `string`. You could simply instead of inserting the pair in a `ostringstream` insert it directly into `std::cout` (or whereever you want to insert it) – 463035818_is_not_an_ai Oct 26 '17 at 18:12

Printing a pair out as a string

0 Answers0