函数适配器

来源：互联网发布：阿里数据包导入淘宝编辑：程序博客网时间：2024/05/16 05:45

#include <iostream>#include <string>#include <vector>#include <functional>using namespace std;void foo(const string &s){    cout << s << endl;}int main(int argc, const char *argv[]){    void (*pFunc) (const string &) = &foo;    pFunc("bar");    function<void (const string&)> f = &foo;    f("bar");        return 0;}

#include <iostream>#include <string>#include <vector>#include <functional>using namespace std;void foo(int i, double d){    cout << i << d << endl;}int main(int argc, const char *argv[]){    function<void (int, double)> f = &foo;    f(12, 4.5);        return 0;}

#include <iostream>#include <string>#include <vector>#include <functional>using namespace std;class Foo{    public:        void foo(int i) { cout << i << endl; }                static void bar(double d) { cout << d << endl; }};int main(int argc, const char *argv[]){    //mem_fun void (*)(Foo *, int)    Foo f;    (mem_fun(&Foo::foo))(&f, 123); //把成员函数转换成函数对象    function<void (int)> pf = bind(&Foo::foo,                                    &f,                                    std::placeholders::_1);    pf(345);    function<void (Foo*, int)> pf2 = bind(&Foo::foo,                                          std::placeholders::_1,                                          std::placeholders::_2);//数字代表原函数第几个参数    pf2(&f, 456);    function<void (int, Foo*)> pf3 = bind(&Foo::foo,                    std::placeholders::_2,                    std::placeholders::_1);    pf3(567, &f);    return 0;}

#include <iostream>#include <string>#include <vector>#include <functional>using namespace std;using namespace std::placeholders;void test(int i, double d, const string &s){    cout << "i = " << i << " d = " << d << " s = " << s << endl;}int main(int argc, const char *argv[]){    function<void (int, double, const string&)> f1 = &test;    f1(12, 3.14, "foo");    //1.void (*)(int, double)    function<void (int, double)> f2 =             std::bind(&test,                      _1,                      _2,                      "foo");    //2.void (*)(double, int, const string &)    function<void (double, int, const string &)> f3 =         std::bind(&test,                  _2,                  _1,                  _3);    //3.void (*)(const string &, int)    function<void (const string &, int)> f4 =         std::bind(&test,                  _2,                  3.4,                  _1);    //4. void (*) (const string &, int, double)    function<void (const string&, int, double)> f5        = std::bind(&test,                    _2,                    _3,                    _1);        //5. void (*)(int)    function<void (int)> f6 =         bind(&test,             _1,             3.4,             "bar");    //6 void(*)(const string &)    function<void (const string &)> f7 =        bind(&test,             12,             4.5,             _1);    //7. void (*)()    function<void()> f8 =         bind(&test,             12,             4.5,             "bar");}

0 0