STL for C++ Programmers
Author: Leen Ammeraal
Publisher: John Wiley
Reviewer: Bob Adkins
Good news—STL, Standard Template Library, is alive and well on Linux. Leen Ammeraal demonstrates this as well as his considerable skills as a master teacher in STL for C++ Programmers. Although the primary focus is not Linux, his many excellent examples are easily adapted to the g++ environment in Linux 2.0++ (his examples adapted for Linux can be found at http://www.cwareco.com/download.html. Ammeraal writes concise yet thorough explanations on each aspect of using STL.
STL started in the 1970s with Alexander Stepanov's ideas about designing general algorithms. Stepanov, together with Meng Lee, took these ideas to HP and developed the first C++ based STL. By 1994, STL was accepted into the C++ draft standard by the ANSI/ISO C++ standards committee.
STL distinguishes general algorithms from the more specialized data and methods encapsulated by ordinary abstract data types. In this way, complex and powerful algorithms can be implemented independently of the data to which they are applied, allowing for generalization and reuse of these algorithms. In STL more familiar object abstraction is reserved for data and methods. These are then tailored and bound to the characteristics of their underlying container type such as sequence containers and associative containers. Examples of this distinction with respect to sequence containers, such as vector objects, are begin, end and insert. These methods access and manipulate the underlying data of the vector container class. However, these methods are specific to the treatment of the data and should not be confused with more general algorithms such as find, sort and other advanced numeric algorithms (e.g., accumulate or inner product). General algorithms are a kind of method abstraction in contrast to more traditional data abstraction.
STL support has been available on Linux since GNU's libg++ 2.6.2. Now with release 188.8.131.52, the library is quite usable for most major features with the exception of name space scoping. There are minor differences with other implementations, such as Borland's BC5 environment, but these differences mostly concern header naming conventions. There is also a curious problem with fstream which involves an unexpected file access mode default.
g++ 2.8.0 will offer a more complete STL based on newer code from SGI and a complete redesign of the compiler's template implementation. Unfortunately, g++ 2.8.0 is not expected to fix the problems with using name spaces.
From the beginning Leen Ammeraal presents a quick and practical startup for the STL beginner. He then explains how to use the sequence containers (vectors, lists and deques), the associative containers (sets and maps) and, later, examines containers derived from these basic types such as stacks, queues and priority queues. As a simple application, he shows how to to build a telephone directory using associative map containers. Later, he demonstrates a more complex map application, called a concordance, which produces a line-oriented index of all words in a text file. He also shows function objects which can be used to build custom ordering relationships among the elements of a container. He moves on to algorithms and the practical details of STL's generic algorithms for manipulating sequences and for sorting. He demonstrates the built-in numeric algorithms which make STL attractive for implementing statistical analysis such as the Least Squares Method.
As his final chapter, Ammeraal presents a wonderfully fun example of “Very Large Numbers”. Here Ammeraal uses STL to calculate pi to an arbitrarily large number of digits. Ammeraal exploits the power of STL to reduce the implementation complexities of defining and operating on extremely large numbers. He notes that, thanks to the STL's vector container, this version is “simpler and more elegant” than an earlier solution he presented in his book Algorithms and Data Structures in C++.
For added spice, I modified his program to generate a histogram of the digits computed for pi. At 100,000 places, digit “1” is a very slight favorite. Moreover, with this example Linux shows its strength. After turning on full g++ optimization, I was able to calculate these 100,000 digits in just under 20 minutes. Under DOS/Windows, Ammeraal indicated that this same calculation took several hours using BC5.
Fast/Flexible Linux OS Recovery
On Demand Now
In this live one-hour webinar, learn how to enhance your existing backup strategies for complete disaster recovery preparedness using Storix System Backup Administrator (SBAdmin), a highly flexible full-system recovery solution for UNIX and Linux systems.
Join Linux Journal's Shawn Powers and David Huffman, President/CEO, Storix, Inc.
Free to Linux Journal readers.Register Now!
- Peppermint 7 Released
- Download "Linux Management with Red Hat Satellite: Measuring Business Impact and ROI"
- Sony Settles in Linux Battle
- Libarchive Security Flaw Discovered
- Maru OS Brings Debian to Your Phone
- Snappy Moves to New Platforms
- Profiles and RC Files
- Git 2.9 Released
- Understanding Ceph and Its Place in the Market
- The Giant Zero, Part 0.x
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide