Having a little problem here with the code below. It compiles all right, but when run it gives me the descriptive error message of "Error: Access Violation". What am I doing wrong?

template StreamInterfaces(T)
{
	interface ReadableStreamInterface
	{
		void read(out T[] buffer, in uint number);
		void sync();
	}
}

template MemoryStream(T)
{
	class MemoryStream : StreamInterfaces!(T).ReadableStreamInterface
	{
		void read(out T[] buffer, in uint number)
		{
			printf("read\n");
		}

		void sync()
		{
			printf("sync\n");
		}
	}
}

int main()
{
	alias MemoryStream!(ubyte) MemoryUByteStream;
	MemoryUByteStream testStream;
	testStream.sync();
	
	ubyte[] buffer;
	testStream.read(buffer, 100);
	
	return 0;
}

Cheers,
Sigbjørn Lund Olsen

Fllrb! Obviously, I am still living the the C++ dreamscape where an object is automatically constructed when declared. Adding "= new MemoryUByteStream" fixed it.

Is there any reason why one has to explicitly 'new' an object?

Cheers,
Sigbjørn Lund Olsen

Sigbjørn Lund Olsen wrote:

> Fllrb! Obviously, I am still living the the C++ dreamscape where an object is automatically constructed when declared. Adding "= new MemoryUByteStream" fixed it.
>
> Is there any reason why one has to explicitly 'new' an object? 

Yes and no.

Objects in D are pointers to objects not objects themselves, therefore its pretty close to C++ (because u have to use new there as well, except D is one symbol shorter).   Whenever u use new, think gc.  I think it may be easier to parse as well.

Of course the syntax could have been simplified (and this has been discussed before).  If you really want the C++ behaviour then it would be the auto version of object creation that you'd want to simplify.

auto object o = new object;

to

auto object o;

That was discussed before.

-- 
-Anderson: http://badmama.com.au/~anderson/

"J Anderson" <REMOVEanderson@badmama.com.au> wrote in message news:c3jpf3$rus$1@digitaldaemon.com...
> Sigbjørn Lund Olsen wrote:
>
> > Fllrb! Obviously, I am still living the the C++ dreamscape where an object is automatically constructed when declared. Adding "= new MemoryUByteStream" fixed it.
> >
> > Is there any reason why one has to explicitly 'new' an object?
>
> Yes and no.
>
> Objects in D are pointers to objects not objects themselves, therefore its pretty close to C++ (because u have to use new there as well, except D is one symbol shorter).   Whenever u use new, think gc.  I think it may be easier to parse as well.
>
> Of course the syntax could have been simplified (and this has been discussed before).  If you really want the C++ behaviour then it would be the auto version of object creation that you'd want to simplify.
>
> auto object o = new object;
>
> to
>
> auto object o;

This should be done. The auto qualifier prevents it from being ambiguous (to compiler or human) and it removes the quite confusing new'ing of an object that's automatic.

J Anderson wrote:

> Sigbjørn Lund Olsen wrote:
> 
>> Fllrb! Obviously, I am still living the the C++ dreamscape where an object is automatically constructed when declared. Adding "= new MemoryUByteStream" fixed it.
>>
>> Is there any reason why one has to explicitly 'new' an object? 
> 
> 
> Yes and no.
> 
> Objects in D are pointers to objects not objects themselves, therefore its pretty close to C++ (because u have to use new there as well, except D is one symbol shorter).   Whenever u use new, think gc.  I think it may be easier to parse as well.
> 
> Of course the syntax could have been simplified (and this has been discussed before).  If you really want the C++ behaviour then it would be the auto version of object creation that you'd want to simplify.
> 
> auto object o = new object;
> 
> to
> 
> auto object o;
> 
> That was discussed before.

Mmhm. Remember what the thread was named (just out of curiousity)? I'm not too fussed about wanting C++ behaviour just for the sake of it - there are too many who'd like D to me an amalgamation of languages Foo, Bar, Doodad, Fwabble, Q--, Visual Perl# Duper Duper etc. Actually explicitly writing 'new object' isn't going to be a problem, for me at least, as long as I remember to do it.

My principal worry is that I'm going to make hordes of bugs while my mind adjusts (and afterwards too?). Error messages, really. I had no idea what was going on for quite a while there, or where it was. Presumably it wouldn't be hard for the compiler to see that 'oh, here's a fool trying to do something to an object that hasn't been constructed - let's throw a compilation error at her' instead of leaving it untill runtime, with as giving a message as "Access Violation, and I'm not going to give you fools a line number, module name, function name, nothing to help you along. So long, and see you next time." (paraphrase)

Cheers,
Sigbjørn Lund Olsen

"Sigbjørn Lund Olsen" <sigbjorn@lundolsen.net> wrote in message news:c3jqj9$ti2$1@digitaldaemon.com...
> J Anderson wrote:
>
> > Sigbjørn Lund Olsen wrote:
> >
> >> Fllrb! Obviously, I am still living the the C++ dreamscape where an object is automatically constructed when declared. Adding "= new MemoryUByteStream" fixed it.
> >>
> >> Is there any reason why one has to explicitly 'new' an object?
> >
> >
> > Yes and no.
> >
> > Objects in D are pointers to objects not objects themselves, therefore its pretty close to C++ (because u have to use new there as well, except D is one symbol shorter).   Whenever u use new, think gc.  I think it may be easier to parse as well.
> >
> > Of course the syntax could have been simplified (and this has been discussed before).  If you really want the C++ behaviour then it would be the auto version of object creation that you'd want to simplify.
> >
> > auto object o = new object;
> >
> > to
> >
> > auto object o;
> >
> > That was discussed before.
>
> Mmhm. Remember what the thread was named (just out of curiousity)? I'm not too fussed about wanting C++ behaviour just for the sake of it - there are too many who'd like D to me an amalgamation of languages Foo, Bar, Doodad, Fwabble, Q--, Visual Perl# Duper Duper etc. Actually explicitly writing 'new object' isn't going to be a problem, for me at least, as long as I remember to do it.

It's appropriate to have to write new when you're constructing a heap based object, but it's a dose of cognitive dissonance to have to do it when the object is auto. We don't have to new structs, do we?

> My principal worry is that I'm going to make hordes of bugs while my mind adjusts (and afterwards too?). Error messages, really. I had no idea what was going on for quite a while there, or where it was. Presumably it wouldn't be hard for the compiler to see that 'oh, here's a fool trying to do something to an object that hasn't been constructed - let's throw a compilation error at her' instead of leaving it untill runtime, with as giving a message as "Access Violation, and I'm not going to give you fools a line number, module name, function name, nothing to help you along. So long, and see you next time." (paraphrase)

The assertion messages are Sh, and need addressing asap. I think there's not much debate on that point, and hopefully Walter'll deal with that just as soon as he's done the whole list of new libraries I just sent him. ;-)

"Sigbjørn Lund Olsen" <sigbjorn@lundolsen.net> wrote in message news:c3jqj9$ti2$1@digitaldaemon.com...
> J Anderson wrote:
>
> > Sigbjørn Lund Olsen wrote:
> >
> >> Fllrb! Obviously, I am still living the the C++ dreamscape where an object is automatically constructed when declared. Adding "= new MemoryUByteStream" fixed it.
> >>
> >> Is there any reason why one has to explicitly 'new' an object?
> >
> >
> > Yes and no.
> >
> > Objects in D are pointers to objects not objects themselves, therefore its pretty close to C++ (because u have to use new there as well, except D is one symbol shorter).   Whenever u use new, think gc.  I think it may be easier to parse as well.
> >
> > Of course the syntax could have been simplified (and this has been discussed before).  If you really want the C++ behaviour then it would be the auto version of object creation that you'd want to simplify.
> >
> > auto object o = new object;
> >
> > to
> >
> > auto object o;
> >
> > That was discussed before.
>
> Mmhm. Remember what the thread was named (just out of curiousity)? I'm not too fussed about wanting C++ behaviour just for the sake of it - there are too many who'd like D to me an amalgamation of languages Foo, Bar, Doodad, Fwabble, Q--, Visual Perl# Duper Duper etc. Actually explicitly writing 'new object' isn't going to be a problem, for me at least, as long as I remember to do it.
>
> My principal worry is that I'm going to make hordes of bugs while my mind adjusts (and afterwards too?). Error messages, really. I had no idea what was going on for quite a while there, or where it was. Presumably it wouldn't be hard for the compiler to see that 'oh, here's a fool trying to do something to an object that hasn't been constructed - let's throw a compilation error at her'

Does this mean that you are the first DWoman
on the NG?

Phill.

Phill wrote:

> "Sigbjørn Lund Olsen" <sigbjorn@lundolsen.net> wrote in message
> news:c3jqj9$ti2$1@digitaldaemon.com...
> 
>>J Anderson wrote:
>>
>>
>>>Sigbjørn Lund Olsen wrote:
>>>
>>>
>>>>Fllrb! Obviously, I am still living the the C++ dreamscape where an
>>>>object is automatically constructed when declared. Adding "= new
>>>>MemoryUByteStream" fixed it.
>>>>
>>>>Is there any reason why one has to explicitly 'new' an object?
>>>
>>>
>>>Yes and no.
>>>
>>>Objects in D are pointers to objects not objects themselves, therefore
>>>its pretty close to C++ (because u have to use new there as well, except
>>>D is one symbol shorter).   Whenever u use new, think gc.  I think it
>>>may be easier to parse as well.
>>>
>>>Of course the syntax could have been simplified (and this has been
>>>discussed before).  If you really want the C++ behaviour then it would
>>>be the auto version of object creation that you'd want to simplify.
>>>
>>>auto object o = new object;
>>>
>>>to
>>>
>>>auto object o;
>>>
>>>That was discussed before.
>>
>>Mmhm. Remember what the thread was named (just out of curiousity)? I'm
>>not too fussed about wanting C++ behaviour just for the sake of it -
>>there are too many who'd like D to me an amalgamation of languages Foo,
>>Bar, Doodad, Fwabble, Q--, Visual Perl# Duper Duper etc. Actually
>>explicitly writing 'new object' isn't going to be a problem, for me at
>>least, as long as I remember to do it.
>>
>>My principal worry is that I'm going to make hordes of bugs while my
>>mind adjusts (and afterwards too?). Error messages, really. I had no
>>idea what was going on for quite a while there, or where it was.
>>Presumably it wouldn't be hard for the compiler to see that 'oh, here's
>>a fool trying to do something to an object that hasn't been constructed
>>- let's throw a compilation error at her'
> 
> 
> Does this mean that you are the first DWoman
> on the NG?

No, it means I like writing 'she' where everyone else (it seems) likes writing 'him', because it catches people off guard and tends to make them think a little bit. Which can't possibly be a bad thing :-)

Cheers,
Sigbjørn Lund Olsen

fair enough :o))


"Sigbjørn Lund Olsen" <sigbjorn@lundolsen.net> wrote in message news:c3m9ct$1rn5$1@digitaldaemon.com...
> Phill wrote:
>
> > "Sigbjørn Lund Olsen" <sigbjorn@lundolsen.net> wrote in message news:c3jqj9$ti2$1@digitaldaemon.com...
> >
> >>J Anderson wrote:
> >>
> >>
> >>>Sigbjørn Lund Olsen wrote:
> >>>
> >>>
> >>>>Fllrb! Obviously, I am still living the the C++ dreamscape where an object is automatically constructed when declared. Adding "= new MemoryUByteStream" fixed it.
> >>>>
> >>>>Is there any reason why one has to explicitly 'new' an object?
> >>>
> >>>
> >>>Yes and no.
> >>>
> >>>Objects in D are pointers to objects not objects themselves, therefore its pretty close to C++ (because u have to use new there as well,
except
> >>>D is one symbol shorter).   Whenever u use new, think gc.  I think it may be easier to parse as well.
> >>>
> >>>Of course the syntax could have been simplified (and this has been discussed before).  If you really want the C++ behaviour then it would be the auto version of object creation that you'd want to simplify.
> >>>
> >>>auto object o = new object;
> >>>
> >>>to
> >>>
> >>>auto object o;
> >>>
> >>>That was discussed before.
> >>
> >>Mmhm. Remember what the thread was named (just out of curiousity)? I'm not too fussed about wanting C++ behaviour just for the sake of it - there are too many who'd like D to me an amalgamation of languages Foo, Bar, Doodad, Fwabble, Q--, Visual Perl# Duper Duper etc. Actually explicitly writing 'new object' isn't going to be a problem, for me at least, as long as I remember to do it.
> >>
> >>My principal worry is that I'm going to make hordes of bugs while my mind adjusts (and afterwards too?). Error messages, really. I had no idea what was going on for quite a while there, or where it was. Presumably it wouldn't be hard for the compiler to see that 'oh, here's a fool trying to do something to an object that hasn't been constructed - let's throw a compilation error at her'
> >
> >
> > Does this mean that you are the first DWoman
> > on the NG?
>
> No, it means I like writing 'she' where everyone else (it seems) likes writing 'him', because it catches people off guard and tends to make them think a little bit. Which can't possibly be a bad thing :-)
>
> Cheers,
> Sigbjørn Lund Olsen