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Creating an ostream with Pair struct

pepstein (100)
I have created a Pair struct to hold pairs but right now it doesn't like the ostream I have created. Specifically, it doesn't like the amount of arguments it takes. The error I'm getting is: error: 'std::ostream& Pair<T1, T2>::operator<<(std::ostream&, const Pair<T1, T2>&)' must take exactly one argument


How do I fix this?

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  template <typename T1, typename T2>
struct Pair;

template <typename T1, typename T2>
std::ostream &operator <<(std::ostream &os, const Pair<T1, T2> &value);

template <typename T1,typename T2>
struct Pair {
		std::ostream &operator << <>(std::ostream &os, const Pair<T1, T2> &value) {
            os << '(' << value.first << ',' << value.second << ')';
            return os;
        }
		Pair(const T1 &first, const T2 &second) {
		this->first = first;
		this->second = second;
	}
	T1 first;
	T2 second;
};
Cubbi (4774)
The code posted is basically a syntax error: "operator << <>" looks like the syntax for a template specialization of a class member function, but it's missing some keywords which depend on what you're trying to do. Based on the rest of it, what you're trying to is to friend a specialization of the non-member template you've declared at lines 4-5: you're missing the keyword "friend"

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template <typename T1,typename T2>
struct Pair {
        friend std::ostream &operator << <>(std::ostream &os, const Pair<T1, T2> &value) {


Last edited on
Yay295 (431)
There is already a pair class in <utility> by the way.
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