Re: C++: Math function round() does not compile - why?
On Tuesday 14 February 2006 11:48, Oliver Elphick wrote: [snip] sprintf(tmp, %.4f, round((double) newqty * price * discpc) / 100.); [snip] orderimpl.cpp:84: implicit declaration of function `int round(...)' this is indeed wierd. %.4f should expect a double, not an int. You could try %.4g or %.4e or ask in comp.lang.c++ or comp.lang.c in USENET.. thomas -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: C++: Math function round() does not compile - why?
Hi Oliver, g++-2.95 -c -pipe -DQWS -fexceptions -fno-rtti -Wall -W -g -std=c99 -I/opt/Qtopia/include -o orderimpl.o orderimpl.cpp orderimpl.cpp: In method `void OrderImpl::calculate_line(int)': orderimpl.cpp:84: implicit declaration of function `int round(...)' this sounds like math.h doesn't give you the prototype for round(). Try to run math.h through the preprocessor alone (g++-2.95 -std=c99 -E /usr/include/math.h), and grep for round. I don't get the definition with g++-3.3 alone, but with g++-3.3 -std=c99 I do... YMMV. I've got no g++-2.95 here to continue the tests. HTH, Jan -- Jan C. Nordholz jckn At gmx net signature.asc Description: Digital signature
Re: C++: Math function round() does not compile - why?
On Tue, 2006-02-14 at 14:11 +0100, Jan C. Nordholz wrote: Hi Oliver, g++-2.95 -c -pipe -DQWS -fexceptions -fno-rtti -Wall -W -g -std=c99 -I/opt/Qtopia/include -o orderimpl.o orderimpl.cpp orderimpl.cpp: In method `void OrderImpl::calculate_line(int)': orderimpl.cpp:84: implicit declaration of function `int round(...)' this sounds like math.h doesn't give you the prototype for round(). Try to run math.h through the preprocessor alone (g++-2.95 -std=c99 -E /usr/include/math.h), and grep for round. I don't get the definition with g++-3.3 alone, but with g++-3.3 -std=c99 I do... YMMV. I've got no g++-2.95 here to continue the tests. with g++-2.95, this gives no prototypes for round(). So it appears that -std=c99 does not work. Is there some way to achieve this for 2.95? (This is now academic, since I have written my own version for this application.) -- Oliver Elphick olly@lfix.co.uk Isle of Wight http://www.lfix.co.uk/oliver GPG: 1024D/A54310EA 92C8 39E7 280E 3631 3F0E 1EC0 5664 7A2F A543 10EA Do you want to know God? http://www.lfix.co.uk/knowing_god.html -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: C++: Math function round() does not compile - why?
Hi, with g++-2.95, this gives no prototypes for round(). So it appears that -std=c99 does not work. Is there some way to achieve this for 2.95? (This is now academic, since I have written my own version for this application.) you could use the features header. Start your source files with #define _ISOC99_SOURCE #include features.h This will toggle the appropriate __USE_* macros (__USE_ISOC99, in this case) that aren't set by the compiler. There are a few other macros you might want to set (_POSIX_SOURCE, or even _GNU_SOURCE), so perhaps you should have a closer look at features.h if you plan to use it directly. Regards, Jan -- Jan C. Nordholz jckn At gmx net signature.asc Description: Digital signature
Re: C++: Math function round() does not compile - why?
2006/2/14, Oliver Elphick olly@lfix.co.uk: I am trying to use the math function round() according to the manpage, but it does not compile. Can anyone explain why not, please? The command line and error are: g++-2.95 -c -pipe -DQWS -fexceptions -fno-rtti -Wall -W -g -std=c99 -I/opt/Qtopia/include -o orderimpl.o orderimpl.cpp orderimpl.cpp: In method `void OrderImpl::calculate_line(int)': orderimpl.cpp:84: implicit declaration of function `int round(...)' Hi, hmmm, have you tried to add the -lm ??? Cheers, Sergio --- http://biorobotics.fi-p.unam.mx -- Meine Hoffnung soll mich leiten Durch die Tage ohne Dich Und die Liebe soll mich tragen Wenn der Schmerz die Hoffnung bricht
Re: C++: Math function round() does not compile - why?
Oliver Elphick wrote: On Tue, 2006-02-14 at 14:11 +0100, Jan C. Nordholz wrote: Hi Oliver, g++-2.95 -c -pipe -DQWS -fexceptions -fno-rtti -Wall -W -g -std=c99 -I/opt/Qtopia/include -o orderimpl.o orderimpl.cpp orderimpl.cpp: In method `void OrderImpl::calculate_line(int)': orderimpl.cpp:84: implicit declaration of function `int round(...)' this sounds like math.h doesn't give you the prototype for round(). Try to run math.h through the preprocessor alone (g++-2.95 -std=c99 -E /usr/include/math.h), and grep for round. I don't get the definition with g++-3.3 alone, but with g++-3.3 -std=c99 I do... YMMV. I've got no g++-2.95 here to continue the tests. with g++-2.95, this gives no prototypes for round(). So it appears that -std=c99 does not work. Is there some way to achieve this for 2.95? (This is now academic, since I have written my own version for this application.) Maybe try defining _ISOC99_SOURCE in your source code before #including math.h? (You might need to put the #define before _any_ #include statement and maybe specifically #include features.h.) For instance: #define _ISOC99_SOURCE #include features.h #include math.h If I've put together the clues correctly, setting this macro is equivalent to the -std=c99 option. See the comment at the top of /usr/include/features.h (after the copyright blurb) for more information. regards, -- Kevin B. McCarty [EMAIL PROTECTED] Physics Department WWW: http://www.princeton.edu/~kmccarty/Princeton University GPG: public key ID 4F83C751 Princeton, NJ 08544 -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: C++: Math function round() does not compile - why? - resolution
On Tue, 2006-02-14 at 15:15 +0100, Jan C. Nordholz wrote: Hi, with g++-2.95, this gives no prototypes for round(). So it appears that -std=c99 does not work. Is there some way to achieve this for 2.95? (This is now academic, since I have written my own version for this application.) you could use the features header. Start your source files with #define _ISOC99_SOURCE #include features.h This will toggle the appropriate __USE_* macros (__USE_ISOC99, in this case) that aren't set by the compiler. There are a few other macros you might want to set (_POSIX_SOURCE, or even _GNU_SOURCE), so perhaps you should have a closer look at features.h if you plan to use it directly. Thanks to you and others for that suggestion. Defining _GNU_SOURCE fixes the problem for g++-2.95. -- Oliver Elphick olly@lfix.co.uk Isle of Wight http://www.lfix.co.uk/oliver GPG: 1024D/A54310EA 92C8 39E7 280E 3631 3F0E 1EC0 5664 7A2F A543 10EA Do you want to know God? http://www.lfix.co.uk/knowing_god.html -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: C++: Math function round() does not compile - why?
On Tue, 2006-02-14 at 09:40 -0600, Sergio Cuéllar Valdés wrote: 2006/2/14, Oliver Elphick olly@lfix.co.uk: I am trying to use the math function round() according to the manpage, but it does not compile. Can anyone explain why not, please? The command line and error are: g++-2.95 -c -pipe -DQWS -fexceptions -fno-rtti -Wall -W -g -std=c99 -I/opt/Qtopia/include -o orderimpl.o orderimpl.cpp orderimpl.cpp: In method `void OrderImpl::calculate_line(int)': orderimpl.cpp:84: implicit declaration of function `int round(...)' Hi, hmmm, have you tried to add the -lm ??? i was thinking the same, but it looks as though he is only compiling, not linking, so one would think that '-lm' would have no impact. -matt zagrabelny -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: C++: Math function round() does not compile - why?
On Tue, 2006-02-14 at 10:54 -0600, Matt Zagrabelny wrote: hmmm, have you tried to add the -lm ??? i was thinking the same, but it looks as though he is only compiling, not linking, so one would think that '-lm' would have no impact. That's right; the -c option was used. This is just one module of many, with the compilation of each module called from a makefile. -- Oliver Elphick olly@lfix.co.uk Isle of Wight http://www.lfix.co.uk/oliver GPG: 1024D/A54310EA 92C8 39E7 280E 3631 3F0E 1EC0 5664 7A2F A543 10EA Do you want to know God? http://www.lfix.co.uk/knowing_god.html -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
