Mega Code Archive
Call member function for each element in vector
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/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
//#define mem_fun1 mem_fun
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <functional>
class Person {
private:
std::string name;
public:
//...
void print () const {
std::cout << name << std::endl;
}
void printWithPrefix (std::string prefix) const {
std::cout << prefix << name << std::endl;
}
};
void foo (const std::vector<Person>& coll)
{
using std::for_each;
using std::bind2nd;
using std::mem_fun_ref;
// call member function print() for each element
for_each (coll.begin(), coll.end(), mem_fun_ref(&Person::print));
// call member function printWithPrefix() for each element
// - "person: " is passed as an argument to the member function
for_each (coll.begin(), coll.end(),bind2nd(mem_fun_ref(&Person::printWithPrefix),"person: "));
}
void ptrfoo (const std::vector<Person*>& coll)
// ^^^ pointer !
{
using std::for_each;
using std::bind2nd;
using std::mem_fun;
// call member function print() for each referred object
for_each (coll.begin(), coll.end(),
mem_fun(&Person::print));
// call member function printWithPrefix() for each referred object
// - "person: " is passed as an argument to the member function
for_each (coll.begin(), coll.end(),bind2nd(mem_fun(&Person::printWithPrefix),"person: "));
}
int main()
{
std::vector<Person> coll(5);
foo(coll);
std::vector<Person*> coll2;
coll2.push_back(new Person);
ptrfoo(coll2);
}
person:
person:
person:
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