Setst和 Multisets

#include <iostream>
#include <set>
using namespace std;

template<class T>
class RuntimeCmp{
public:
	enum cmp_mode{normal,reverse};
private:
	cmp_mode mode;
public:
	RuntimeCmp(cmp_mode m=normal):mode(m){}
	bool operator() (const T& t1,const T& t2) const{
		return mode==normal ?t1<t2:t2<t1;
	}
	bool operator==(const RuntimeCmp& rc){
		return mode==rc.mode;
	}
};

typedef set<int,RuntimeCmp<int>> IntSet;
void fill(IntSet& set);


int main()
{
	IntSet coll1;
	fill(coll1);
	RuntimeCmp<int> reverse_order(RuntimeCmp<int>::reverse);

	IntSet coll2(reverse_order);
	fill(coll2);

	coll1=coll2;
	coll1.insert(3);

	if (coll1.value_comp()==coll2.value_comp())
	{

	}
	else{}
}

void fill(IntSet& set)
{
	set.insert(4);
	set.insert(7);
	set.insert(5);
	set.insert(1);
	set.insert(6);
	set.insert(2);
	set.insert(5);
}