C++标准库---ptr_fun()

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ptr_fun是将一个普通的函数适配成一个仿函数(functor), 添加上argument_type和result type等类型.

例如：

#include <algorithm>  #include <functional>  #include <iostream>  using namespace std;  int sum(int arg1, int arg2)  {  std::cout<< "arg1 = " << arg1 << std::endl;  std::cout<< "arg2 = " << arg2 << std::endl;  int sum = arg1 + arg2;  std::cout << "sum = " << sum << std::endl;  return sum;  }int main(int argc, char *argv[], char *env[]){  bind1st(ptr_fun(sum), 1)(2);// the same as sum(1,2)  bind2nd(ptr_fun(sum), 1)(2);// the same as sum(2,1)  system("pause");return 0;}

运行结果：

代码示例：

#include<iostream>#include<vector>#include<algorithm>#include<functional>#include<string>using namespace std;int main(){vector<char*> coll;vector<char*>::iterator iter1,iter2;coll.push_back("lan");coll.push_back("zhi");coll.push_back("hui");coll.push_back("is");coll.push_back("a");coll.push_back("good");coll.push_back("boy!");for(iter1=coll.begin();iter1!=coll.end();++iter1){cout<<*iter1<<" ";}cout<<endl;iter2=find_if(coll.begin(),coll.end(),not1(bind2nd(ptr_fun(strcmp),"hui")));//hui与coll中所有字符串比较,如果相同，则反相后输出if(iter2!=coll.end()){cout<<"Found: "<<*iter2<<endl;}else{cout<<"Not Found"<<endl;}system("pause");return 0;}

运行结果：

lanzhihui is a good boy

Found: hui

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