Bjarne Stroustrup on the Evolution of Languages

vart · 05-01-2008, 12:52 AM

http://msdn.microsoft.com/en-us/magazine/cc500572.aspx
I have this link in my Microsoft subscription letter. Maybe it will be of some interest for others...

manav · 05-01-2008, 07:24 AM

I liked the fact that he himself is unhappy about some things in C++

This makes me feel better, if even the creator can't change some things, then, at least I should stop rambling about some tiny problems, that usually come by me, sometimes !

Waiting for C++0x although!

medievalelks · 05-01-2008, 07:59 AM

Good interview. Loved the bit at the end about cell phones. I love how games, video, cameras, etc. are all being perfected by I still routinely get dropped calls, missed voice mails, etc. Flash over substance, which seems to be the norm anymore.

Mario F. · 05-01-2008, 08:08 AM

It still pains me bjarne fully supports the auto keyword. Bah!

*defeated*

**laserlight** · 05-01-2008, 08:26 AM

Quote:

It still pains me bjarne fully supports the auto keyword. Bah!

What's wrong with the new use of auto?

Mario F. · 05-01-2008, 09:09 AM

Quote:

Originally Posted by laserlight

What's wrong with the new use of auto?

At the surface nothing:
- You get more expressiveness (syntactical);
- You save on keystrokes;
- You minimize (debatable) compile time errors.

Complex template base object declarations are made simpler, I foresee iterators being one of the favorite uses for auto. But also, as suggested on the article, "hard to acquire" types can be easily declared.

However, I believe auto is an accident waiting to happen. For one, you lose semantical expressiveness and you make the code logic harder to follow. auto almost feels like I'm wanting to program in a non typed system; i.e. "I don't know the type, I just know it's some form of X, I can't bothered checking the library documentation, or it is too long to type, so I go with auto. This will work."

But the above argument has it flaws, I concede. I only recently started giving template based programming a hard look. And already I'm faced with annoying type declarations that I wished (truly) had been made simpler. As such, I can only imagine what the above paragraph may look like to a seasoned template based programmer.

My major beef with it is instead the fact the new use of auto is an accident waiting to happen also because of the fact it opens yet another door for bad code. The fact it is openly discussed as a tool for the beginner programmer, by the very same people who are institutionalizing it, only makes this worse. You know what I mean, but for illustration purposes, the following is not something you, I, or anyone else would like to see in the years to come on the C++ board:

Code:

std::string foo(int x);

int main () {
    auto bar = foo(13);
}

And yet, I foresee this is exactly what is going to happen.

EDIT: Note that the loss of semantical value is no minor issue. The amount of inconvinient and confusing bugs that might arise from auto foo = "This is a string"; when written by a programming language beginner is overwhelming. Is auto in this instance helping him, or on the other hand making his life harder for not even making it clear this variable is a const char*? Can we say type obfuscation? I chose this example because, believe it or not, is what you can see here: http://en.wikipedia.org/wiki/C%2B%2B0x

EDIT 2: Just a minor correction; one doesn't need to be a seasoned "template based programmer" (allow me that expression yet again) to experience the need for auto, as anyone who has, for instance, constructed a complex STL container can attest.

vart · 05-01-2008, 09:16 AM

I've found it funny to see him discuss the vector<Apple> and vector<Fruit> after seeing same discussion on this forum...

**CornedBee** · 05-01-2008, 12:51 PM

Thanks, vart, that was a great article. And I also greatly enjoyed the linked paper about multiple dispatch.

Quote:

Is auto in this instance helping him, or on the other hand making his life harder for not even making it clear this variable is a const char*?

The worst part is that it isn't. The type of a string literal is const char[N], where N is the number of chars in the string literal, including the terminator. The type of a wide string literal is const wchar_t[N], same rule.
What does this mean? It means this:

Code:

const char *s1 = "foo";
const char *s2 = "foo";
assert(s1 == s2); // Probably true. Compilers generally fold string literals.

auto a1 = "bar";
auto a2 = "bar";
assert(a1 == a2); // Definitely false. On a side note, you've just wasted 8 stack bytes for nothing.

I need to go edit that Wikipedia article.

vart · 05-01-2008, 12:57 PM

Quote:

Thanks, vart

It makes me happy to see that people find this link useful... So you're wellcome.

Mario F. · 05-01-2008, 01:06 PM

Quiet right, CornedBee. And yet another reason to be carefull around auto.

But for all purposes the example shouldn't even be there, in my opinion, because it suggests exactly what I'm against with; an oversimplification of its true usefulness that will introduce a new crowd of bad code and hard to track bugs. It pains me especially that it is advertised as being introduced to help the life of newcomers to the language.

Personally I feel auto is an advanced feature that is (un)fortunately extremely easy to use. This contradiction only means use and abuse of auto will probably become all too prevalent.

**CornedBee** · 05-01-2008, 01:28 PM

Probably. But as one of those seasoned template programmers you refer to, I'm way too happy about auto to care about its abuse by newbies.

**Bubba** · 05-01-2008, 07:43 PM

Good read. I'm concerned with auto but I guess I'll get used to its uses and abuses. Bjarne seems to be a fundamentals type fella which is nice because he realizes that new bells and whistles or the latest greatest thing does not always make a good language. Overall I like the new features that were mentioned and look forward to learning and working with the new standard (sometime in the next few years?). Since it was 2003 to 2005 before most compilers caught up to the most recent standard I doubt I will see a compiler up to the new standard for quite some time.

**CornedBee** · 05-02-2008, 03:07 AM

Quote:

Originally Posted by Bubba

Overall I like the new features that were mentioned and look forward to learning and working with the new standard (sometime in the next few years?).

Depends on how much of them you want. GCC will develop support gradually. Vararg templates and r-value references are there now, in GCC 4.3.

manav · 05-02-2008, 03:13 AM

An offtopic question:

Quote:

Originally Posted by CornedBee

All the buzzt!

What that means?

**CornedBee** · 05-02-2008, 03:30 AM

It means, "All the best!", that is, a well-wishing, with altered spelling to make a pun on my username. I've been using it as long as the username exists.

05-01-2008, 12:52 AM	#1
vart CSharpener Join Date: Oct 2006 Posts: 5,242	Bjarne Stroustrup on the Evolution of Languages - Interview MSDN Magazine Apr 2008 http://msdn.microsoft.com/en-us/magazine/cc500572.aspx I have this link in my Microsoft subscription letter. Maybe it will be of some interest for others... __________________ If I have eight hours for cutting wood, I spend six sharpening my axe.
vart is offline

05-01-2008, 07:24 AM	#2
manav Banned Join Date: Nov 2007 Posts: 678	I liked the fact that he himself is unhappy about some things in C++ This makes me feel better, if even the creator can't change some things, then, at least I should stop rambling about some tiny problems, that usually come by me, sometimes ! Waiting for C++0x although!
manav is offline

05-01-2008, 07:59 AM	#3
medievalelks Afraid of widths Join Date: Apr 2008 Location: Chicago Posts: 887	Good interview. Loved the bit at the end about cell phones. I love how games, video, cameras, etc. are all being perfected by I still routinely get dropped calls, missed voice mails, etc. Flash over substance, which seems to be the norm anymore.
medievalelks is offline

05-01-2008, 08:08 AM	#4
Mario F. (?<!re)tired Join Date: May 2006 Location: Portugal Posts: 5,220	It still pains me bjarne fully supports the auto keyword. Bah! defeated __________________ Originally Posted by brewbuck: Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.
Mario F. is offline

05-01-2008, 09:16 AM	#7
vart CSharpener Join Date: Oct 2006 Posts: 5,242	I've found it funny to see him discuss the vector<Apple> and vector<Fruit> after seeing same discussion on this forum... __________________ If I have eight hours for cutting wood, I spend six sharpening my axe.
vart is offline

05-01-2008, 01:06 PM	#10
Mario F. (?<!re)tired Join Date: May 2006 Location: Portugal Posts: 5,220	Quiet right, CornedBee. And yet another reason to be carefull around auto. But for all purposes the example shouldn't even be there, in my opinion, because it suggests exactly what I'm against with; an oversimplification of its true usefulness that will introduce a new crowd of bad code and hard to track bugs. It pains me especially that it is advertised as being introduced to help the life of newcomers to the language. Personally I feel auto is an advanced feature that is (un)fortunately extremely easy to use. This contradiction only means use and abuse of auto will probably become all too prevalent. __________________ Originally Posted by brewbuck: Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.
Mario F. is offline

05-01-2008, 01:28 PM	#11
CornedBee Cat without Hat Join Date: Apr 2003 Posts: 8,439	Probably. But as one of those seasoned template programmers you refer to, I'm way too happy about auto to care about its abuse by newbies. __________________ All the buzzt! CornedBee "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code." - Flon's Law
CornedBee is offline

05-01-2008, 07:43 PM	#12
Bubba Super Moderator Join Date: Aug 2001 Posts: 7,472	Good read. I'm concerned with auto but I guess I'll get used to its uses and abuses. Bjarne seems to be a fundamentals type fella which is nice because he realizes that new bells and whistles or the latest greatest thing does not always make a good language. Overall I like the new features that were mentioned and look forward to learning and working with the new standard (sometime in the next few years?). Since it was 2003 to 2005 before most compilers caught up to the most recent standard I doubt I will see a compiler up to the new standard for quite some time.
Bubba is offline

05-02-2008, 03:30 AM	#15
CornedBee Cat without Hat Join Date: Apr 2003 Posts: 8,439	It means, "All the best!", that is, a well-wishing, with altered spelling to make a pun on my username. I've been using it as long as the username exists. __________________ All the buzzt! CornedBee "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code." - Flon's Law
CornedBee is offline

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