www.gusucode.com > C++ Primer 书籍源代码源码程序 > C++ Primer 书籍源代码源码程序/code/7/usefcnptr.cpp
//Download by http://www.NewXing.com /* * This file contains code from "C++ Primer, Fourth Edition", by Stanley B. * Lippman, Jose Lajoie, and Barbara E. Moo, and is covered under the * copyright and warranty notices given in that book: * * "Copyright (c) 2005 by Objectwrite, Inc., Jose Lajoie, and Barbara E. Moo." * * * "The authors and publisher have taken care in the preparation of this book, * but make no expressed or implied warranty of any kind and assume no * responsibility for errors or omissions. No liability is assumed for * incidental or consequential damages in connection with or arising out of the * use of the information or programs contained herein." * * Permission is granted for this code to be used for educational purposes in * association with the book, given proper citation if and when posted or * reproduced.Any commercial use of this code requires the explicit written * permission of the publisher, Addison-Wesley Professional, a division of * Pearson Education, Inc. Send your request for permission, stating clearly * what code you would like to use, and in what specific way, to the following * address: * * Pearson Education, Inc. * Rights and Contracts Department * 75 Arlington Street, Suite 300 * Boston, MA 02216 * Fax: (617) 848-7047 */ #include <iostream> #include <vector> using std::vector; using std::endl; using std::cout; // function to return minimum element in an vector of ints int min_element(vector<int>::iterator, vector<int>::iterator); // pointer to function, initialized to point to min_element int (*pf)(vector<int>::iterator, vector<int>::iterator) = min_element; int main() { vector<int> ivec; // give ivec some values for (vector<int>::size_type i = 0; i < 10; ++i) ivec.push_back(i); cout << "Direct call: " << min_element(ivec.begin(), ivec.end()) << endl; cout << "Indirect call: " << pf(ivec.begin(), ivec.end()) << endl; return 0; } // returns minimum element in an vector of ints int min_element(vector<int>::iterator beg, vector<int>::iterator end) { int minVal = 0; while (beg != end) { if (minVal > *beg) minVal = *beg; ++beg; } return minVal; }