#include <cassert>
#include <functional>
#include <iostream>
#include <iterator>
#include <set>
#include <string>
#include <vector>
struct MyClass
{
MyClass(const std::string& s, const int x) : m_s(s), m_x(x) {}
const std::string m_s;
const int m_x;
};
bool operator<(const MyClass& lhs, const MyClass& rhs) = delete;
//Display x first
std::ostream& operator<<(std::ostream& os, const MyClass& m)
{
os << m.m_x << ' ' << m.m_s;
return os;
}
int main()
{
std::set<MyClass,std::function<bool(MyClass,MyClass)>> s(
[](const MyClass& lhs, const MyClass& rhs)
{
return lhs.m_x < rhs.m_x;
}
);
//Insert ordered by s
s.insert(MyClass("five",5));
s.insert(MyClass("four",4));
s.insert(MyClass("one",1));
s.insert(MyClass("six",6));
s.insert(MyClass("three",3));
s.insert(MyClass("two",2));
//Show that the set orders by MyClass their x
std::copy(s.begin(),s.end(),std::ostream_iterator<MyClass>(std::cout,"\n"));
}
/* Screen output:
1 one
2 two
3 three
4 four
5 five
6 six
Press <RETURN> to close this window...
*/
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