computer science

IBM Open Class

IBM Open Class is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand IBM Open Class rather than just read about it. In short: IBM Open Class (IOC) is an IBM C++ product originally developed by Kevin Leong and originally known under several names in the C++ industry, including ICL (IBM Class Library), UICL (User Interface Class Library), and OCL (Open Class Library). IOC was an extensive set of C++ classes used to build CLI and GUI applications which could then be easily cross-compiled to OS/2, Microsoft Windows, and AIX.

Key takeaways

IBM Open Class belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect IBM Open Class to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of IBM Open Class from memory before moving on to harder problems.

Reference excerpt

IBM Open Class (IOC) is an IBM C++ product originally developed by Kevin Leong and originally known under several names in the C++ industry, including ICL (IBM Class Library), UICL (User Interface Class Library), and OCL (Open Class Library). IOC was an extensive set of C++ classes used to build CLI and GUI applications which could then be easily cross-compiled to OS/2, Microsoft Windows, and AIX. IOC also formed the basis for IBM's VisualAge for C++ graphical application builder. The non-GUI portions of IOC were available for z/OS and OS/400.

History of IOC

The IOC was included as part of IBM's C++ compiler environment. Applications developed with IOC could be distributed with a royalty-free runtime, or could be statically linked against the IOC libraries. Initially only available for OS/2, the IOC was eventually made available for Windows, AIX, z/OS, and OS/400. Support for the OS/2 and Windows VisualAge for C++ compiler—as well as the accompanying IOC—was officially withdrawn by IBM on April 27, 2001.[1] IOC was removed from z/OS 1.9, introduced in 2007.

C/Set++ v2.01 for OS/2 (1993) VisualAge C++ for OS/2, version 3.0 VisualAge for C++ for Windows, version 3.5 C and C++ Compilers for OS/2, AIX, and for Windows NT, version 3.6 C and C++ Compilers for OS/2 and Windows, version 3.65 (1998?) VisualAge C++ Professional for OS/2 and Windows NT, version 4.0 (1998)

Examples The most widely recognized example of a simple application that uses the IOC is hello world:

#include <iframe.hpp>

Other examples of commonly used IOC classes and methods include:

#include <istring.hpp>

#include <icmdhdr.hpp>

Notes ^ IBM's Withdrawal Announcement #901-013 (announced on January 23, 2001, effective on April 27, 2001)

External links news://ibm.software.vacpp.openclass ISBN 0-442-01795-2 (C++ Class Library: Power GUI Programming with CSet++) ISBN 0-471-16482-8 (Power GUI Programming with VisualAge for C++)

Illustrations

Worked examples

Example 1 — a first encounter with IBM Open Class

Start with the simplest possible case. Write down what IBM Open Class claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to IBM Open Class before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about IBM Open Class ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of IBM Open Class

In research: IBM Open Class appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses IBM Open Class in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: IBM Open Class is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1993 software, C++ libraries, IBM software, so understanding it makes those chapters shorter.
In everyday life: Look for IBM Open Class outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study IBM Open Class in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what IBM Open Class means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain IBM Open Class out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is IBM Open Class in simple terms?

Why does IBM Open Class matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study IBM Open Class?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on IBM Open Class.