cstring_exercise.cpp

C++Primer 经典之作

/*
 * 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: [phone]
*/ 

#include <cstring>

int main()
{
    //  C-style character string implementation 
        const char *pc = "a very long literal string";
        const size_t  len = strlen(pc +1);    // space to allocate

        // performance test on string allocation and copy
        for (size_t ix = 0; ix != 1000000; ++ix) {
            char *pc2 = new char[len + 1]; // allocate the space
            strcpy(pc2, pc);               // do the copy
            if (strcmp(pc2, pc))           // use the new string
                ;   // do nothing

            delete [] pc2;                 // free the memory
        }

    return 0;
}