C++ USES the find_if function instance of STL in member functions

This article illustrates how C++ USES the find_if function of STL in member functions. Share with you for your reference. Specific methods are analyzed as follows:

In general, STL's find_if function is powerful enough to perform a lookup using the input function substitution equal operator (there is a lot of information on the web, but I won't go into it here).

Such as finding an array of odd number, you can use the following code completion (specific reference here: http://www.cplusplus.com/reference/algorithm/find_if/) :

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

bool IsOdd (int i) {
 return ((i%2)==1);
}

int main () {
 vector<int> myvector;
 vector<int>::iterator it;

 myvector.push_back(10);
 myvector.push_back(25);
 myvector.push_back(40);
 myvector.push_back(55);

 it = find_if (myvector.begin(), myvector.end(), IsOdd);
 cout << "The first odd value is " << *it << endl;

 return 0;
}

Operation results:

The first odd value is 25

What happens if you add this code to a class and write it as a member of the class?

For example, the following class code:

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

class CTest
{
public:
 bool IsOdd (int i) {
  return ((i%2)==1);
 }

 int test () {
  vector<int> myvector;
  vector<int>::iterator it;
  myvector.push_back(10);
  myvector.push_back(25);
  myvector.push_back(40);
  myvector.push_back(55);
  it = find_if (myvector.begin(), myvector.end(), IsOdd);
  cout << "The first odd value is " << *it << endl;
  return 0;
 }
};
int main()
{
 CTest t1;
 t1.test();
 return 0;
}

Errors like the following occur:

Error C3867: 'CTest::IsOdd': function call missing argument list; Use '&CTest::IsOdd' to create a pointer to member

Today I encountered this problem, here is the solution posted for reference only:

It = find_if (myvector. Begin (), myvector. End (), IsOdd);

To:

It = find_if (myvector. The begin (), myvector. The end (), STD: : bind1st (STD: : mem_fun (& CTest: : IsOdd), this));

Bind1st function and mem_fun function plus this pointer.

Complete sample code click here (link: http://xiazai.jb51.net/201410/yuanma/stl_find_if_inMemeberFun (jb51.net). Rar).

Hope that the article described in the C++ programming to help you.