World: r3wp

He was asking about changing the original. The only way to do that 
is to pass a reference to the series or context that contains the 
original value slot.

if the frame is just a copy, is it possible to get the original?

yes, that's correct.  I though he want's to do something like:
d: 0.0
change-decimal d
probe d
== 1.234

The frame is just another set of value slots that the values are 
copied into. You can only get the original by passing a reference 
to the value slot container. There are no free value slots.

yes.. that's what I wanted to do:)

(whic is not possible)

yes, that won't work for you

ok

because the arg passed to the command function is just a copy of 
the real value

you need to return it

or as Brian said you could do:
d: [0.0]
change-decimal d
probe d/1
== 1.234

(but you should be using the protext_GC function to be safe)

better to avoid it.

but it a little bit complicates the automatic building of wrappers 
for functions like that. btw... at this moment I can build imageMagick 
extension by parsing it's doc (~4500 lines of C code:).  Just must 
solve a few functions where it's using this approach to return multiple 
values and add some validity checks to make the extension safer.

Brian: actually the values on the 'command frame' are 'free value 
slots' as they are not part of any series...they are just in plain 
fixed size array. But  this is probably just playing with words ;)

They are in the command frame :)

ok :)

Oldes: I don't think you can do it different way since REBOL has 
no c-like pointers.

The only way is to generate rebol wrapper func which will pass the 
args in a block! or object! imo.

(Or binary! :)

ok.. no problem.. I was just asking as I'm learning. It's just something 
like educative free time project for me as I don't need it.. I use 
maybe 20 functions of IM in real life.

(and I could use Jocko's extension for the rest if needed of course)

Next question.. when I have:
		case CMD_MagickGetImageColors: {
			if(current_wand) {
				RXA_INT32(frm, 1) = MagickGetImageColors(
					current_wand);
				RXA_TYPE(frm, 1) = RXT_INTEGER;
			}
			return RXR_VALUE;
		}

While compilation using GCC I get this warning: use of cast expressions 
as lvalues is deprecated

The command is working, just would like to know if I can improve 
it somehow. The function is defined as:
	size_t MagickGetImageColors(MagickWand *wand)

That's due to how RXA_INT32 is defined.

Use RXA_INT64 instead, and the warning will go away.

Right.. that's it.

Having:
	double mean, standard_deviation;
What I must do to get REBOL block with these two values in it?

This seems to be working, but is this the best solution?
	REBSER* block = RL_MAKE_BLOCK(2);
	RXIARG val;
	RXV_DEC64(val) = mean;
	RL_SET_VALUE(block, 0, val, RXT_DECIMAL);
	RXV_DEC64(val) = standard_deviation;
	RL_SET_VALUE(block, 1, val, RXT_DECIMAL);
	RXA_TYPE(frm, 1) = RXT_BLOCK;
	RXA_SERIES(frm, 1) = block;

I have MP3 playing from R3 console using FMOD extension... at this 
moment just a very first test:) Must go sleep unfortunately.

really cool.

I started using Code::Blocks and now I get error:
	invalid conversion from 'const char*' to 'REBYTE*'
for code:
	RL->print("init\n");
Which was fine with GCC. Any idea why?

Also I see such a warnings:

 ..\src\include\reb-config.h|109|warning: ignoring #pragma warning 
 |

A110?

yes

Windows? Linux?

Windows

I've got it... the file was .cpp instead of .c

(the warning is still there, but I can print again)

Do you know, if it's (or will be) possible to get struct! from handle!?

Or to return struct! from the C side?

Passing around heap-allocated structs should work right now.

Ah, struct!, sorry, I misread.

..because I somehow miss what is struct useful for in R3 without 
routines.

I think struct! is just a datatype for future use. Not used at the 
moment.

yes, struct! is 'reserved' for now. It may be even removed later.

What if I expect float on the C side, but still want to allow to 
use integer from REBOL (using number!).. what's the best way to do 
it?

Maybe a wrapper interface function in the init block?

That's possible, but I was more thinking how to do it on the C side 
and not end with wrapper for each extension command.

Yeah, more elegant, but more work

How about defining the command with `command [arg [integer! decimal!]]` 
and then detecting in C when you where passed an int and converting 
it to a float?