Re: "Must instantiate controlled types at library level." Why?

[Martin Krischik <krischik@users.sourceforge.net>]

Hyman Rosen wrote:

> Ludovic Brenta wrote:
>> You are not being helpful to anyone with this comment.  If you think I
>> am ignorant, please explain why, or otherwise give me one good reason
>> not to put your name in my kill file.
> 
> Oh, by all means put my name in your kill file!
> 
> But OK. You state that "The std::vector template class is not
> a first-class citizen". I haven't a clue as to what that might
> mean

Ruffly: First class is everything you can use without (in C/C++) "#include"
or (in Ada) "with" or (in Java) "import".

vector <> is not a first class citizen because you need "#include <vector>"

And, of corse, to copy the hole content of an other file into your own file
is cheating.

More precisely: First class are only keywords, predefined operators,
predefined types, (in Ada ) attribute and perhaps pragmas.

Actually: Even "#include" isn't first class since it is part of a
preprocessor. 

I am unsure if, in Ada, Integer is first class since there is an implicit
"with Standart; use Standart;".

The argument is that everything inside a language need to be implemented
with first class citizen - they are the fondatation of everything else and
design errors in this area have profound consequences.

Out of my 10 years+ experience with C/C++ I say that the following are my
personal top 3 C/C++ design mistakes which lead to most of bugs I had to
hunt down insted the compiler just finding them for me.

1) #include instead of an proper import/with. 
2) implicit type convertion. 
3) arrays are pointers. 

With Regards

Martin
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