boost::bind实践

 1 /*Beyond the C++ Standard Library ( An Introduction to Boost )[CN].chm*/
 2 /*bind的用法*/
 3 
 4 #include <iostream>
 5 #include <algorithm>
 6 #include <functional>
 7 #include <vector>
 8 
 9 #include <boost/bind/bind.hpp>
10 #include <boost/bind/apply.hpp>
11 #include <boost/smart_ptr/shared_ptr.hpp>
12 
13 using namespace std;
14 using namespace boost;
15 
16 int f(int a, int b)
17 {
18     return a + b;
19 }
20 
21 int g(int a, int b, int c)
22 {
23     return a + b + c;
24 }
25 
26 bool preFind(int a, int b)
27 {
28     return a<b;
29 }
30 bool preFind2(int a, int b, int c)
31 {
32     return a<b && a<c;
33 }
34 struct predicate
35 {
36     typedef void result_type;
37     void operator() (int a, int b)
38     {
39         cout << a << "+" << b << "=" << a+b << endl;
40     }
41 };
42 struct X
43 {
44     void f(int a)
45     {
46         cout << "a = " << a << endl;
47     }
48     void f2(int a, int b)
49     {
50         cout << a << "+" << b << "=" << a+b << endl;
51     }
52     predicate pre;
53     int arrElem;
54     int *parrElem;
55 };
56 
57 void main()
58 {
59     int arr[5] = {1, 2, 3, 4, 5};
60     //int ret1 = std::count_if(arr, arr+5, boost::bind(preFind, _1, 2));
61     //cout << ret1 << endl;
62     //int ret2 = std::count_if(arr, arr+5, boost::bind(preFind, 2, _2));
63     //cout << ret2 << endl;
64     //std::for_each (arr, arr+5, boost::bind(preFind, _1, 2));
65     //std::for_each (arr, arr+5, boost::bind(predicate(), _1, 2));
66     //std::for_each (arr, arr+5, boost::bind(boost::type<void>(), predicate(), _1, 2));
67     //std::for_each (arr, arr+5, boost::bind(preFind2, _1, 2, 3));
68     //std::for_each (arr, arr+5, boost::bind(preFind2, _1, 2, _1));
69     //boost::bind(preFind2, 5, _2, 3);
70     //std::for_each (arr, arr+5, boost::bind(preFind2, 5, _2, 3));
71 
72     //boost::bind(preFind, _1, 2);
73     //boost::bind(preFind, _2, 2);
74     //boost::bind(preFind, _1, _2);
75     //boost::bind(preFind, _2, _1);
76     //boost::bind(preFind2, _1, _2, _3);
77     //boost::bind(predicate(), _1, _2);
78     //boost::bind(boost::type<void>(), predicate(), _1, _2);
79 
80     //X x;
81     //boost::bind(&X::f, boost::ref(x), _1);
82     //boost::bind(&X::f, _1, 1);
83     //boost::bind(&X::f, _1, _2);
84     //boost::bind(&X::pre, _1);
85     //std::for_each (arr, arr+5, boost::bind(&X::f, x, _1));
86     //std::for_each (arr, arr+5, boost::bind(&X::f2, boost::ref(x), _1, 2));
87     //std::for_each (arr, arr+5, boost::bind(&X::f2, &x, _1, 2));
88     //boost::shared_ptr<X> p(new X);
89     //std::for_each (arr, arr+5, boost::bind(&X::f2, p, _1, 2));
90     std::vector<X*> arrs;
91     for (int i=0 ; i!=5 ; ++i)
92     {
93         arrs.push_back(new X);
94     }
95     std::for_each (arrs.begin(), arrs.end(), boost::bind(&X::arrElem, _1));
96     std::for_each (arrs.begin(), arrs.end(), boost::bind(&X::f, _1, 2));
97 }

 1 /*Beyond the C++ Standard Library ( An Introduction to Boost )[CN].chm*/
 2 /*bind的用法*/
 3 
 4 #include <iostream>
 5 #include <algorithm>
 6 #include <functional>
 7 #include <vector>
 8 
 9 #include <boost/bind/bind.hpp>
10 #include <boost/smart_ptr/shared_ptr.hpp>
11 
12 using namespace std;
13 using namespace boost;
14 
15 class status 
16 {  
17 public:
18     std::string name_;  
19     bool ok_;
20 public:  
21     status(const std::string& name):name_(name),ok_(true) {}  
22     void break_it() {    ok_=false;  }  
23     bool is_broken() const {    return ok_;  }  
24     void report() const 
25     {    
26         std::cout << name_.c_str() << " is " << (ok_ ? "working nominally":"terribly broken") << std::endl;  
27     }
28 };
29 
30 void nine_arguments(  int i1,int i2,int i3,int i4,  int i5,int i6,int i7,int i8, int i9)
31 {  
32     std::cout << i1 << i2 << i3 << i4 << i5 << i6 << i7 << i8 << i9 << ‘\n‘;
33 }
34 int main() 
35 {  
36     int i1=1,i2=2,i3=3,i4=4,i5=5,i6=6,i7=7,i8=8,i9=9;  
37     (boost::bind(&nine_arguments,_9,_2,_1,_6,_3,_8,_4,_5,_7))(i1,i2,i3,i4,i5,i6,i7,i8,i9);
38 
39 
40     //std::vector<status> statuses;
41     //statuses.push_back(status("status 1"));
42     //statuses.push_back(status("status 2"));
43     //statuses.push_back(status("status 3"));
44     //statuses.push_back(status("status 4"));
45     //statuses[1].break_it();
46     //statuses[2].break_it();
47     ////method 1:
48     //for (std::vector<status>::iterator it=statuses.begin();  it!=statuses.end();++it) 
49     //{  
50     //    it->report();
51     //}
52     ////method 2: ok
53     //std::for_each(  statuses.begin(),  statuses.end(),  std::mem_fun_ref(&status::report));
54     ////method 3: ok
55     //std::for_each(  statuses.begin(),  statuses.end(),  boost::bind(&status::report, _1));
56     ////others ok
57     //std::for_each(  statuses.begin(),  statuses.end(),  boost::bind(&status::name_, _1));
58 
59     //std::vector<status*> p_statuses;
60     //p_statuses.push_back(new status("status 1"));
61     //p_statuses.push_back(new status("status 2"));
62     //p_statuses.push_back(new status("status 3"));
63     //p_statuses.push_back(new status("status 4"));
64     //p_statuses[1]->break_it();
65     //p_statuses[2]->break_it();
66     ////method 2: ok
67     //std::for_each(  p_statuses.begin(),  p_statuses.end(),  std::mem_fun(&status::report));
68     ////method 3: ok
69     //std::for_each(  p_statuses.begin(),  p_statuses.end(),  boost::bind(&status::report, _1));
70 
71     std::vector<boost::shared_ptr<status> > s_statuses;
72     s_statuses.push_back(  boost::shared_ptr<status>(new status("status 1")));
73     s_statuses.push_back(  boost::shared_ptr<status>(new status("status 2")));
74     s_statuses.push_back(  boost::shared_ptr<status>(new status("status 3")));
75     s_statuses.push_back(  boost::shared_ptr<status>(new status("status 4")));
76     s_statuses[1]->break_it();
77     s_statuses[2]->break_it();
78     //method 2: error
79     //std::for_each(  s_statuses.begin(),  s_statuses.end(),  std::mem_fun(&status::report));
80     //method 3: ok
81     std::for_each(  s_statuses.begin(),  s_statuses.end(),  boost::bind(&status::report, _1));
82 
83 
84 }