Abstract: Expression Templates is a C++ technique for passing expressions as function arguments. The expression can be inlined into the function body, which results in faster and more convenient code than C-style callback functions. This technique can also be used to evaluate vector and matrix expressions in a single pass without temporaries. In preliminary benchmark results, one compiler evaluates vector expressions at 95-99.5% efficiency of hand- coded C using this technique (for long vectors). The speed is 2-15 times that of a conventional C++ vector class.
The introduction of templates to C++ added a facility whereby the compiler can act as an interpreter. This makes it possible to write programs in a subset of C++ which are interpreted at compile time. Language features such as for loops and if statements can be replaced by template specialization and recursion. The first examples of these techniques were written by Erwin Unruh and circulated among members of the ANSI/ISO C++ standardization committee [1]. These programs didn’t have to be executed — they generated their output at compile time as warning messages. For example, one program generated warning messages containing prime numbers when compiled.
Exception handling can be a very personal and complex topic. The C language gave the programmer very few exception handling capabilities, as the programmers wanted more control over exceptions themselves. Thankfully, the C++ standards committee crafted a simple, but powerful form of exception handling for the C++ language that still gives the programmer quite a bit of control. Many coders eschew this method that I will present shortly, so more power to you. Most of the information I learned on C++ exception handling was from the wonderful Deep C++ column on MSDN.
The new C++ standard is full of powerful additions to the language: templates, run-time type identification (RTTI), namespaces, and exceptions to name a few. Rather than talk about one of these “major” extensions, I will discuss one of the minor extensions: the new C++ casting operators.
This article discusses three related problems in the design of C++ classes and surveys five of the solutions to them found in the literature. These problems and solutions are considered together because they relate to separating the design choices that are manifested in the interface from those that are made in implementing the class. The problems are:
Imagine that you are about to finish a relatively large program, one that has taken a few weeks or months to write and debug. Just as you are putting the finishing touches on it, you discover that it is either too slow or runs out of memory when you feed it a realistic set of input data. You sigh, and start the task of optimizing it.
This document aims to provide people who have done an introductory C++ course the skills required to write bigger programs. Online versions are at http://www-h.eng.cam.ac.uk/help/tpl/languages/C++/doc/doc.html (HTML); http://www-h.eng.cam.ac.uk/help/tpl/languages/C++/doc/doc.pdf (PDF); and http://www-h.eng.cam.ac.uk/help/documentation/docsource/index.html (LaTeX).
This text enunciates and illustrates features and basic principles of C++. It is aimed at experienced C users who wish to learn C++. It can also be interesting for beginner C++ users who leaved out some possibilities of the language. A printed version is available at http://www.lulu.com/content/258714
The language C++ has features which make it attractive for scientific computing: templates for generic programming, operator overloading for expressiveness, and object-orientation for abstraction and code reuse. Despite these features, the scientific computing community has been reluctant to adopt C++, partly due to performance problems. In the early 1990s, C++ programs were much slower than their Fortran counterparts — typical benchmarks showed C++ lagging behind Fortran’s performance by anywhere from 20% to a factor of ten. Users of C++ often rewrote the number crunching parts of their programs in Fortran to get acceptable performance.
This course was intended for students who want to learn more about object-oriented programming. Concepts presented are exemplified using the C++ programming language. This course is not intended to learn C++ in all its details. If you are interested in the language, please check out the Suggested Reading page for a reference to other online tutorials.