On Mon, 02 Mar 2009 06:28:24 +0300, hasen <hasan.alj...@gmail.com> wrote:
I haven't been following D for over a year .. now I notice there's a
const!!
In C++, in my experience, the only time I need const is when I pass
temporary objects by reference and the compiler refuses, so I make the
parameter const to make the compiler happy.
void my_func( const SomeType& obj ) { ... }
This is annoying because now const propagates like a virus! any function
that I call on `obj` must also be changed to accept a `const` reference.
any method on obj which doesn't change it must also be marked as
`const` in order for it to be callable from inside this function.
This whole stupid process wouldn't even be needed in the first place if
C++ had a garbage collector, because then I would always "new" them (as
per Java, C#, and D)
SomeType *obj = new SomeType();
but because there's no garbage collector, I have to create the object
not as a reference.
SomeType obj();
Again, this is all stupid C++ stuff that shouldn't even be needed in the
first place.
However, with all that being said, that's just my opinion, maybe over
the time some people found some actually useful uses for const, great,
so they can use it if they want.
What really annoys me is the viral nature of const.
Yesterday I was reading this:
http://www.digitalmars.com/d/2.0/const3.html
(btw, this page is empty: http://www.digitalmars.com/d/2.0/const.html )
and, to my surprise, I see:
char[] p = "world"; // error, cannot implicitly convert invariant
// to mutable
and all I can think of is: WHAT - THE - HELL??!!!!!!
invariant(char)[] is ugly! might as well be saying std::vector<char>
(ok, not the best example of stupidity, but I hope you get my point).
(and, is invariant(char)[] the correct type? or must it be
invariant(char)[5]??)
This is not the D that I loved. What's going on?
P.S. look here
http://stackoverflow.com/questions/557011/d-programming-language-char-arrays/
I know you can use "auto" and all that, but still .. I don't feel good
about this.
I you don't understand something, it doesn't mean something is wrong with the
language. Perhaps, something wrong with you.
Regarding this exaple:
char[] p = "world";
It is rejected for a reason. Modifying the "world" through p will cause a
segfault anyway. So it *must* be const. In case it won't, it will cause bugs that are
even worse to track:
// file 1
char[] a = "hello";
a[4] = '!';
// file 2
writefln("hello"); // prints 'hell!'
