1 #include <iostream>
 2 #include <iterator>
 3 #include <set>
 4 using namespace std;
 5 int main(){
 6     typedef set<int,greater<int> > IntSet;
 7     IntSet coll1;
 8     coll1.insert(4);
 9     coll1.insert(3);
10     coll1.insert(5);
11     coll1.insert(1);
12     coll1.insert(6);
13     coll1.insert(2);
14     coll1.insert(5);
15
16     copy(coll1.begin(),coll1.end(),ostream_iterator<int>(cout," "));
17     cout<<endl;
18
19     pair<IntSet::iterator,bool> status = coll1.insert(4);
20     if(status.second){
21         cout<<"4 is inserted"<<endl<<distance(coll1.begin(),status.first)+1<<endl;
22     }else{
23         cout<<"4 is already existed!"<<endl;
24         coll1.insert(7);
25     }
26
27     copy(coll1.begin(),coll1.end(),ostream_iterator<int>(cout," "));
28     cout<<endl;
29
30     set<int> coll2(coll1.begin(),coll1.end());
31     copy(coll2.begin(),coll2.end(),ostream_iterator<int>(cout," "));
32     cout<<endl;
33
34     coll2.erase(coll2.begin(),coll2.find(3));
35
36     copy(coll2.begin(),coll2.end(),ostream_iterator<int>(cout," "));
37     cout<<endl;
38
39     cout<<coll2.erase(5)<<" elem of 5 is removed!"<<endl;
40
41     copy(coll2.begin(),coll2.end(),ostream_iterator<int>(cout," "));
42     cout<<endl;
43
44
45     return 0;
46 }

 1 #include <iostream>
 2 #include <iterator>
 3 #include <set>
 4 using namespace std;
 5 int main(){
 6     typedef multiset<int,greater<int> > IntSet;
 7     IntSet coll1;
 8     coll1.insert(4);
 9     coll1.insert(3);
10     coll1.insert(5);
11     coll1.insert(1);
12     coll1.insert(6);
13     coll1.insert(2);
14     coll1.insert(5);
15
16     copy(coll1.begin(),coll1.end(),ostream_iterator<int>(cout," "));
17     cout<<endl;
18
19     // 这里运行重复值, 所以没有返回失败状态.
20     IntSet::iterator pos = coll1.insert(4);
21     if(pos!=coll1.end()){
22         cout<<"4 is inserted"<<endl<<distance(coll1.begin(),pos)+1<<endl;
23     }else{
24         cout<<"4 is can't be insert!"<<endl;
25         coll1.insert(7);
26     }
27
28     copy(coll1.begin(),coll1.end(),ostream_iterator<int>(cout," "));
29     cout<<endl;
30
31     multiset<int> coll2(coll1.begin(),coll1.end());
32     copy(coll2.begin(),coll2.end(),ostream_iterator<int>(cout," "));
33     cout<<endl;
34
35     coll2.erase(coll2.begin(),coll2.find(3));
36
37     copy(coll2.begin(),coll2.end(),ostream_iterator<int>(cout," "));
38     cout<<endl;
39
40     cout<<coll2.erase(5)<<" elem of 5 is removed!"<<endl;
41
42     copy(coll2.begin(),coll2.end(),ostream_iterator<int>(cout," "));
43     cout<<endl;
44
45     return 0;
46 }

 1 #include <iostream>
 2 #include <iterator>
 3 #include <set>
 4 using namespace std;
 5 template <class T>
 6 class RuntimeCmp{
 7 public:
 8     enum cmp_mode {normal, reverse};
 9 private:
10     cmp_mode mode; //在同一个类中定义了枚举, 然后定义变量.
11 public:
12     RuntimeCmp(cmp_mode m=normal): mode(m){}
13     bool operator()(const T& t1, const T& t2) const{
14         return mode == normal? t1<t2: t1>t2;
15     }
16     // 返回值给谁用?
17     bool operator == (const RuntimeCmp& rc){
18         return mode == rc.mode;
19     }
20 };
21 typedef set<int,RuntimeCmp<int> > IntSet;
22 void fill(IntSet & set){
23     set.insert(4);
24     set.insert(7);
25     set.insert(5);
26     set.insert(1);
27     set.insert(6);
28     set.insert(2);
29     set.insert(5);
30 }
31 int main(){
32     IntSet coll1;
33     fill(coll1);
34     copy(coll1.begin(),coll1.end(),ostream_iterator<int>(cout," "));
35     cout<<endl;
36     RuntimeCmp<int> reverse_order(RuntimeCmp<int>::reverse);
37     IntSet coll2(reverse_order);
38     fill(coll2);
39     copy(coll2.begin(),coll2.end(),ostream_iterator<int>(cout," "));
40     cout<<endl;
41     coll1 = coll2;
42     coll1.insert(3);
43     copy(coll1.begin(),coll1.end(),ostream_iterator<int>(cout," "));
44     cout<<endl;
45     //比较排序准则是否一致, 由于coll1 从coll2 拷贝而来, 所以一致.
46     cout<<(coll1.value_comp() == coll2.value_comp())<<endl;
47
48     return 0;
49 }