Games people play

[Walter Bright]

Georg Wrede wrote:
> Or, could it be that D actually is bigger than C++ _feature_wise_, while 
> C++ is _much_ larger than D when we look at the ramifications of their 
> respective feature sets.

D *is* bigger feature wise. But complexity wise, C++ beats it. The 
trouble with C++ is that its features are not very orthogonal - and 
where they interact/conflict there are a lot of weird special case 
rules. I have recently exchanged yet another set of emails with a person 
who is a top C++ expert who insisted that DMC++ had a serious bug with 
template name lookups. Turns out that DMC++ actually was implementing 
the name lookup rules *according to the C++ standard* and the other 
compilers were not. The bottom line is even the experts don't know how 
it is supposed to work.

Another example is the preprocessor. It took 10+ years for C/C++ 
compiler vendors to implement it correctly. This isn't because doing a 
macro processor is inherently difficult, it is because the specification 
for C's macro language is so obtuse and full of bizarre special cases. I 
know I've spent countless hours trying to figure out (1) how it's 
supposed to work and (2) how to implement it. It's been scrapped and 
totally reimplemented about 4 times.


> What I mean is, one could write a "complete" 
> book about D, and it still would be just a fraction of the size of 
> Stroustrup's "C++". And that's because most of his book explains and 
> chews on issues and implications that are unobvious to the reader or 
> programmer, and that demand knowing them lest you shoot yourself in the 
> foot -- and not even later understand what happened.
> 
> D has virtually no such crap, so we can scrap 500 pages right off the bat.

Consider just one issue with C++ - how to write a "correct" iterator 
class. Even harder is writing a "correct" container class.