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Stroustrup on the Future of C++

/ASCII writes "Bjarne Stroustrup, the father of C++, has written an essay [PDF] on the features of the upcoming C++0x standard. In his essay, he argues that new features should whenever possible go into the standard library and not into the language, but that the language needs to shave of a few rough corners to make it easier to use for novices."

14 of 661 comments (clear)

  1. wait a moment... by Anonymous Coward · · Score: 5, Funny
    [...] to make it easier to use for novices.
    Doesn't this qualify as blasphemy?
    1. Re:wait a moment... by insert+cool+name · · Score: 5, Funny

      Doesn't this qualify as blasphemy?

      Not when it's God talking.

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  2. Dynamics in programming languages by jurt1235 · · Score: 5, Insightful

    It is interesting to see how an abstract language like a programming language evolves through time. I would think that in a language like C++ the more userfriendlyness should be in the libraries and not in the language, so I agree with the author on this point. Putting it in the libraries makes it better backwards compatible, and distributable.

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    1. Re:Dynamics in programming languages by orthogonal · · Score: 5, Informative

      It is interesting to see how an abstract language like a programming language evolves through time

      If you find that interesting, you're going to love Stroustrup's The Design and Evolution of C++.

      It's an almost novelistic discussion of how he made C in to C++, the various trade-offs required, and how he decided what changes to make or not make. For example, why the dot operator (".") can't be overloaded, but the parentheses can be, and why (contra Goslings Java) operator overloading is a good thing (short answer: it makes syntax match semantics).

      If you ever want, or need, to develop a large-scale, flexible and general system of anything (and what's more general than C++, a programming language used by millions to write both Object Oriented and just "better C" code?), D&E is a wealth of experience, carefully and fully explained.

      And, like a novel, it's for the most part a fun read. Grab a copy, and you'll not only understand C++ better, you'll understand why C++ is what it is, and how it got there from C.

  3. A better wheel by Anonymous Coward · · Score: 5, Insightful

    Am I the only one who wonders why we need a successor to C or C++?

    I've sat through the past 10 years and watched things like Java and D and Objective C come, but meanwhile most serious OS level and game development continues to be in C or C++. Doesn't this demonstrate that new language are merely a distraction to developers who haven't fully exploited the current set?

    1. Re:A better wheel by onnel · · Score: 5, Insightful

      No, it's more a signifier that different problems need different solutions. If all you have is a hammer, everything may look like a nail, but if you know c++, perl, php, java and a few others, your toolbox will contain an appropriate solution for a broad range of problems. I write my games in c++, my websites in php and my text parsing utilities in php. Java and python also serve their niches. Anyone who believes that a single language is the best solution to all of the broad range of problems faced by programmers is sorely mistaken. Onnel

      --

  4. Re:I'm curious ... by strongmace · · Score: 5, Funny

    See Plus Plus Ox

    ...or you could just shorten it by taking out the plus plus and having C0x which is obviously pronounced cocks

    --
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  5. What we need is "Smoothed out" people... by brockbr · · Score: 5, Insightful

    Every time a cost of entry is reduced and the expected prerequisites are thrown aside, the result is a truly less capable *person*, not a more capable tool.

    Agreed - There are some things that need smoothing, but I for one am tired of dealing with people who lack a fundamental understanding of the *systems* as a whole. Examples of this are the folks coming out with CS degrees who aren't even capable of following a thought, let alone starting an actual career designing and developing software.

    For them, a tool like Java offers an entry level that is acceptable given there current capabilities - A tool geared towards THAT user (and a fine one at that).

    But C (and C++) can be leveraged by people who know the tool and *use* the tool for what it can do, even with it's high(er, intellectually) cost of entry.

  6. Re:I'm curious ... by Trailer+Park+Boy · · Score: 5, Informative

    That's 0x as in 05 as in 2005. So C++05 or C++06.

  7. Re:a 'few' rough edges by /ASCII · · Score: 5, Informative
    If you would read the actual article, you would see that the edges Stroustroup talks about are little warts like :

    • whitespace sensitvity in templates, i.e. vector> is a syntax error, since >> is a single token.
    • Type declarating iterator variables can be a huge pain when using STL since the names are so long, i.e. the type 'vector >::const_iterator' is a bit of a mouthfull. Such variables can be guessed from the return type, so you could use a type 'auto' for this.


    Java does not remove a few warts from C++, it forces you to use a Garbage collector, OO design, type introspection, etc, etc. Those are pretty fundamental changes.
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  8. Features I want... by BAILOPAN · · Score: 5, Interesting

    I program in C++ from dawn to dusk, and a few things really irk me about it:

    1. Member function pointers. Implementation dependent and messy syntax that few people even know about. Their use is limited, and they don't support delegates like C#, making them ugly to work with.

    2. The "virtual =0" syntax instead of something nice like "abstract" or "interface" is just weird. How can you set a prototype equal to 0? What's wrong with nice words?

    3. Operator new and delete were designed by someone on crack. The only way to call a constructor is with placement new, whose syntax looks like: new (var) type(). Placement delete, however, doesn't call the destructor, which must be invoked manually. Furthermore, delete can't take parameters like new. What.

    4. There is a "typeid" operator but no "typeof" operator. GCC has an extension for this, but it's not standard C++ I think.

    I'm sure there are other language constructs that have annoyed me, and if you don't read my mind and fix them, Bjarne, I will kick you in the pants!

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    1. Re:Features I want... by Anonymous Coward · · Score: 5, Informative
      1. Member function pointers. Implementation dependent and messy syntax that few people even know about. Their use is limited, and they don't support delegates like C#, making them ugly to work with.

      False. Member function pointers are standardized and not implementation dependent. They do have a syntax that is unusual, however. It's unreasonable to expect C++ to support delegates "like C#" considering that C# was designed long after C++.

      2. The "virtual =0" syntax instead of something nice like "abstract" or "interface" is just weird. How can you set a prototype equal to 0? What's wrong with nice words?

      There is hesitation to introduce keywords, for fear of breaking backwards compatibility. If you program in C++ from dawn to dusk, the =0 notation should be perfectly normal to you, and not a problem in the slightest. They could have made it more descriptive, but it's certainly not a showstopper, and no C++ programmers I know even notice it anymore, as it is just a part of how things are done. Maybe it's a problem for newbies, but you're only a newbie for a short time.

      3. Operator new and delete were designed by someone on crack. The only way to call a constructor is with placement new, whose syntax looks like: new (var) type(). Placement delete, however, doesn't call the destructor, which must be invoked manually. Furthermore, delete can't take parameters like new. What. You cannot call constructors, PERIOD. Placement new is not invoking a constructor, it's evaluating a "new expression" using an allocator function that returns the address it is given, and a SIDE EFFECT of that is the invocation of the constructor. It's simply impossible to directly call a constructor in C++.

      As for "placement delete", I think you lack understanding. Users are not supposed to invoke placement delete, they are supposed to just invoke the destructor for objects created with placement new. Placement delete is only used to cleanup the memory when an exception causes the constructor to fail. And, as an obviously competant C++ programmer, you should know that if the constructor exits with an exception, the destructor is NOT invoked because the object wasn't constructed and therefore doesn't really exist. Operator new and delete are about MEMORY MANAGEMENT and not object lifetime issues. Constructor and destructors are about that. A "new expression" makes use of operator new and also invokes a constructor. You seem to have confused the "new expression" for operator new.

      4. There is a "typeid" operator but no "typeof" operator. GCC has an extension for this, but it's not standard C++ I think.

      You're correct, and you may find that we're trying to address this topic in C++0X. If you're interested, see http://www.open-std.org/jtc1/sc22/wg21/docs/papers /2004/n1737.pdf

  9. Syntactic candy. by mcc · · Score: 5, Insightful
    This is mere unnecessary conveniences. What exactly are they giving us here? Well, if I'm reading this right, "C++0x"* will give us:
    • Some cases where you can type ; where previously {} was necessary, saving as many as two keystrokes.
    • The lexer ambiguity where a<b<c>> and a<b<c> > meant entirely different things is fixed, saving as many as one keystroke.
    • EVEN MORE "free" constructors which may or may not work quite the way you wanted them to in practice.
    • More "fancy cast" operators, which sounds nice until you remember that if there's ever a time you find yourself using the C++ "fancy cast" operators, then there is a damn good chance that it's because you're doing something unwise enough it really would be a better idea to refactor the code to make the "fancy cast" unnecessary.
    ...in the meantime the fundamental issues with C++ remain not only unresolved, but unaddressed. The template system is still not a generics system, but an ugly cut & paste macro system which can incidentally be used for generics, with some caveats. The class system is still fundamentally brittle and unfriendly to simple things such as upgrading a DLL or determining at runtime if two objects are of the same type. The syntax is still a forest of features whose features interact in ways so crazy and unpredictable it approaches Perl in its chaos; references are still gimped; the distinctions in behavior and use between static and dynamic objects remain awkward and newbie-unfriendly. The features that people obviously desire to have in the language as demonstrated by their tendency to hack them in with third-party libraries (like BOOST) are-- they tell us-- a good thing, and they tell us we should continue to hack them in with libraries (like BOOST). That's nice. You know, that would be a lot easier though if we had a macro system** capable of anything smarter than blind code cut and paste-- or at least a macro system** fundamentally designed to be used for anything at all other than generics.

    Meanwhile, it appears if I'm reading this right that the most important differences in C++0x will be changes to the standard library. Great. The STL was defined how many years ago, and it's only just in the last few years that compliant implementations have become commonplace? How many decades will it be before the "C++0x" library changes have become common in a cross-platform compatible way?

    C++ is an extremely useful language, and making an update to C++ which changes as little as possible so as to follow some kind of "if it aint broken don't fix it" principle is an idea which makes a whole lot of sense. However it seems likely to me from reading this that C++0x will offer so little significant difference from C++ as to make itself simply redundant.

    * ("C++0x". Were they specifically trying to come up with a name less convenient than "C#"? Ah well, I guess we can call it "COX" or "cocks" for short.)
    ** "Template system"
  10. Re:Dogma by orthogonal · · Score: 5, Funny

    "I sometimes find distributing an extra 30 MB [the .net run-time] a bit inconvenient."

    Please download my new folding bicycle! Its lightweight aluminum frame means it's easily portable and rugged too! when not biking, fold it up and carry it under your arm like a briefcase! The perfect form of personal transportation!*

    * Note: lightweight bicycle application is powered by a Soviet-era nuclear submarine, a separate download.