Computerworld is undertaking a series of investigations into the most widely-used programming languages. Previously we have spoken to Alfred v. Aho of AWK fame, S. Tucker Taft on the Ada 1995 and 2005 revisions, Microsoft about its server-side script engine ASP, Chet Ramey about his experience maintaining Bash, and Charles H. Moore about the design and development of Forth.

In this interview, we chat to Bjarne Stroustrup of C++ fame about the design and development of C++, garbage collection and the role of facial hair in successful programming languages. Stroustrup is currently the College of Engineering Chair and Computer Science Professor at Texas A&M University, and is an AT&T labs fellow.

What prompted the development of C++?

I needed a tool for designing and implementing a distributed version of the Unix kernel. At the time, 1979, no such tool existed. I needed something that could express the structure of a program, deal directly with hardware, and be sufficiently efficient and sufficiently portable for serious systems programming.

You can find more detailed information about the design and evolution of C++ in my HOPL (History of Programming Languages) papers, which you can find on my home pages, and in my book "The Design and Evolution of C++".

Was there a particular problem you were trying to solve?

The two problems that stick in my mind were to simulate the inter-process communication infrastructure for a distributed or shared-memory system (to determine which OS services we could afford to run on separate processors), and [the need] to write the network drivers for such a system. Obviously - since Unix was written in C - I also wanted a high degree of C compatibility. Very early, 1980 onwards, it was used by other people (helped by me) for simulations of various network protocols and traffic management algorithms.

Where does the name C++ come from?

As "C with Classes" (my ancestor to C++) became popular within Bell Labs, some people found that name too much of a mouthful and started to call it C. This meant that they needed to qualify what they meant when they wanted to refer to Dennis Ritchie's language, so they used "Old C", "Straight C", and such. Somebody found that disrespectful to Dennis (neither Dennis nor I felt that) and one day I received a "request" though Bell Labs management channels to find a better name. As a result, we referred to C++ as C84 for a while. That didn't do much good, so I asked around for suggestions and picked C++ from the resulting list. Everybody agreed that semantically ++C would have been even better, but I thought that would create too many problems for non-geeks.