Article ID: 170199
Article Last Modified on 12/2/2003
APPLIES TO
- The Standard C++ Library, when used with:
- Microsoft Visual C++ 4.2 Enterprise Edition
- Microsoft Visual C++ 4.2 Professional Edition
- Microsoft Visual C++ 5.0 Enterprise Edition
- Microsoft Visual C++ 5.0 Professional Edition
- Microsoft Visual C++ 6.0 Enterprise Edition
- Microsoft Visual C++ 6.0 Professional Edition
- Microsoft Visual C++ 6.0 Standard Edition
This article was previously published under Q170199
SUMMARY
The sample code below illustrates how to use the slice::length, slice::start, and slice::stride STL functions in Visual C++.
Note that there are some differences in the implementation of the Standard C++ Library components in Visual C++ version 4.2 versus later revisions. The relevant sections of code below compile conditionally based upon the value of _MSC_VER.
MORE INFORMATION
Required Header
<valarray>
Prototype
class slice
{
public:
slice();
slice(size_t st, size_t len, size_t str);
size_t start() const;
#if _MSC_VER == 1020 // version 4.2 - declare length()
size_t length() const;
#else // later than version 4.2, length changed to size()
size_t size() const;
#endif
size_t stride() const;
};
NOTE: The class/parameter names in the prototype may not match the version in the header file. Some have been modified to improve readability.
Description
This sample demonstrates the use of STL slice array to change "Hello World!" string to "Hello There." string.
Sample Code
//////////////////////////////////////////////////////////////////////
//
// Compile options needed: None
//
// <filename> : main.cpp
//
// Functions:
//
// slice::length, slice::start, slice::stride
//
// Written by Yeong-Kah Tam
// of Microsoft Product Support Services,
// Copyright (c) 1996 Microsoft Corporation. All rights reserved.
//////////////////////////////////////////////////////////////////////
#include <iostream> // for i/o functions
#include <valarray> // for valarray
using namespace std;
#if _MSC_VER > 1020 // if VC++ version is > 4.2
using namespace std; // std c++ libs implemented in std
#endif
void main()
{
// Initialize string 1 to contain "Hello World!",
// and string 2 to contain "There".
valarray<char> string1("Hello World!", 12);
valarray<char> string2("There.", 6);
// Display both strings.
cout << "String 1 = ";
int strlen;
#if _MSC_VER == 1020 // version 4.2 - call length
strlen = string1.length();
#else // later than 4.2 - call size
strlen = string1.size();
#endif
for (int i = 0; i < strlen; i++)
cout << string1[i];
cout << "\r\n";
cout << "String 2 = ";
#if _MSC_VER == 1020 // version 4.2 - call length
strlen = string2.length();
#else // later than 4.2 - call size
strlen = string2.size();
#endif
for (i = 0; i < strlen; i++)
cout << string2[i];
cout << "\r\n\r\n";
// slice(6, 6, 1) creates a slice array of
//{6, 7, 8, 9, 10, 11} which is used to select
// the elements of string1. "World!" it is. In
// turn, these elements are replaced by the corresponding
// element in string2.
slice slice_obj(6, 6, 1);
string1[slice_obj] = string2;
// Display starting index, length,
// and stride of the slice object.
cout << "slice - starting index = " << slice_obj.start();
cout << "\r\n";
#if _MSC_VER == 1020 // version 4.2 - call length
cout << "slice - length = " << slice_obj.length() << "\r\n";
#else // later than 4.2 - call size
cout << "slice - length = " << slice_obj.size() << "\r\n";
#endif
cout << "slice - stride = " << slice_obj.stride() << "\r\n";
cout << "\r\n";
// Now print out the result.
cout << "After the change, String 1 = ";
#if _MSC_VER == 1020 // version 4.2 - call length
strlen = string1.length();
#else // later than 4.2 - call size
strlen = string1.size();
#endif
for(i = 0; i < strlen; i++)
cout << string1[i];
cout << "\r\n";
}
Program Output
String 1 = Hello World!
String 2 = There.
slice - starting index = 6
slice - length = 6
slice - stride = 1
After the change, String 1 = Hello There.
REFERENCES
Visual C++ Books On Line: Visual C++ Books:C/C++:Standard C++ Library Reference.
Additional query words: STL STLSample length start stride (c) Microsoft Corporation 1997, All Rights Reserved. Contributions by Yeong-Kah Tam,
Keywords: kbhowto KB170199
