- Beginners questions regarding argument transferral and findingall available functions (linux) - 22 Updates
- "Unicode" - 2 Updates
- Object to member conversions - 1 Update
| Jerry Stuckle <jstucklex@attglobal.net>: Aug 30 08:47AM -0400 On 8/30/2016 8:01 AM, R.Wieser wrote: > Any other ideas ? > Regards, > Rudy Wieser Look at his update again. He isn't using the address of the first member - he isn't referencing any member of the struct. You can take the address of it with & and dereference it with *. For instance: struct hostent server; // the actual structure struct hostent* pserver = &server; // A pointer to the structure At this level, it's really no different than other variables, i.e. int i; // an int int *ip = &i; // A pointer to an int And you can use them just like other pointers, i.e. void f(struct hostent * ps); f(&server); // Use the address of the structure f(pserver); // Use a pointer to the structure Does this help? And I agree with the others - you really need to find a good basic book on C++ (or here, even C). It will help you much more than trying to fumble your way through. -- ================== Remove the "x" from my email address Jerry Stuckle jstucklex@attglobal.net ================== |
| Chris Vine <chris@cvine--nospam--.freeserve.co.uk>: Aug 30 01:59PM +0100 On Tue, 30 Aug 2016 11:33:23 +0200 > Odd: several replies, but none that actually told me how its done. > Is it some deep-dark secret that only masters of the trade are > allowed to know ? You have been told the answer (see the response of 29 August at 19:16:59 UTC). 'server', as in: struct hostent *server; is declared as a pointer and can be passed as a pointer. It _is_ a pointer. You only need to dereference it if you want to obtain the structure's members. There is no secret here. It is the most basic C. You really do need to get a decent textbook on the C language. (Or the C++ language if that is what you want to learn.) > not appreciate further hints in the same direction though!) > Do I really need to waste hours googeling hoping I will stumble over > the (most likely rather simple) answer ? Don't google. When learning a language get a textbook to learn the basics. Part of the confusion may be that when you said you were "a novice in regard to using C++ (GCC) *and* using linux" people thought that it was the specific gcc and linux issues you were unfamiliar with, not the basics of C and C++ itself. You gave the impression that you had done some windows programming. The other difficulty is that you have an attitude problem which is considerably larger than your state of knowledge; this is going to get you into trouble, both in your code and in your interactions on this news group. Chris |
| "R.Wieser" <address@not.available>: Aug 30 03:14PM +0200 Paavo, > I express my opinions, you express yours. Nope. You use your "opinions" as an excuse not to post anything in regard to an answer to the problem as I posted it. "Go away. Go learn for yourself. If you do not you will never discover what its all about". Really ? *Thats* how you help people ? In that case, I wonder what you would do if you would *not* be willing to help ... > Yes, that was concrete enough, thank you. Good. > 2) foobar(reinterpret_cast<unsigned char*>(server2)); Why are you writing it like that, when my posted code uses a different make-up (syntax?) *AND* I've indicated I'm a beginner ? But, lets assume you ment: foobar( (unsigned char*) server2 ); Than you're mistaken (adding brackets around "server2" does not help either). Oh, it *compiles* well enough, but the argument in the foobar function will than be pointing at the the value stored into that "server2" variable, not the data in the "hostent" structure. Also explain to me how currently foobar( (unsigned char*) server2-> h_addr ); works for me, but I than can just remove the "->h_addr" part and get the same (compile-time!) result ... > A proper code sample is preferably a complete source > file including all the #includes as well as int main(). Forget it. The only thing it would lead to is that you (and others like you) would making suggestions about *everything* in there, but not the problem. Heck, even now you have troubles with concentrating yourself on the problem. Over the years I've posted enough questions (few, but enough) to have encountered the above many times. Shucks, why do you think I named the function "foobar" instead of its actual name ? Thats because what it, and the rest of the code does has got *nothing* to do with the *compile-time* problem. But, if you are amadant about only being able to glean the problem (and its answer) from such full code I could waste some time to gut everything irrelevant outof my current code (while ofcourse still causing the compile-time error mind you). Apart from the includes for the standard IO, the structure, the gethostbyname function, a minimal "main" declaration and an as minimal "foobar" one (being fully gutted) you would see nothing more than what I already posted. By the way: have you already tried to put those three lines of code I posted in my initial message into some test program and seen if you could get it to compile ? Why not ? I think it would probably have been quite the eye-opener for you. Regards, Rudy Wieser -- Origional message: Paavo Helde <myfirstname@osa.pri.ee> schreef in berichtnieuws M6idnSfk5aQA6VjKnZ2dnUU78dvNnZ2d@giganews.com... > >> I'm just saying that it is not productive to learn language > >> basics from a newsgroup, it's too tedious and chaotic. > > Please, let *me* be the judge of that. This is a tiny bit of knowledge, > > which, if solved, allows me to progress quite a bit. > Why are not judging here anything, I express my opinions, you express yours. > > 2) struct hostent *server2; > > For *both* of the above I want to give a pointer to the actual hostent > > structure to a function called "foobar", which expects the argument to be of > using it in the same meaning.) > >> and preferably with a real code sample, not a vague description ... > > Thats what I posted and am using in my code. I'm sorry, but I have no idea |
| Paavo Helde <myfirstname@osa.pri.ee>: Aug 30 04:22PM +0300 On 30.08.2016 16:14, R.Wieser wrote: > yourself. If you do not you will never discover what its all about". > Really ? *Thats* how you help people ? In that case, I wonder what you > would do if you would *not* be willing to help ... (plonk) |
| "R.Wieser" <address@not.available>: Aug 30 03:28PM +0200 Scott, > The man pages are your friend. :-) I was, just as under Windows, trying to go the opposite way -- from function to documentation -- (Windows does not really have any decent "man" page support), but yes, "man" seems to work rather well under Linux. And thanks for the info-selection methods too. Regards, Rudy Wieser -- Origional mesage: Scott Lurndal <scott@slp53.sl.home> schreef in berichtnieuws Gafxz.1214$LR.855@fx17.iad... > >> to include stdio.h, use > >> #include <stdio.h> > >Thats exactly the problem. How do I know that I need to include stdio.h and > ... > $ man 3 printf | head -20 > PRINTF(3) Linux Programmer's Manual PRINTF(3) > NAME > printf, fprintf, sprintf, snprintf, vprintf, vfprintf, vsprintf, vsnprintf - formatted output conversion |
| "R.Wieser" <address@not.available>: Aug 30 03:22PM +0200 Scott, > $ nm -D /usr/lib64/libzip.so.2 | grep " T " |more Looks like its very usable, thanks. :-) Regards, Rudy Wieser -- Origional message: Scott Lurndal <scott@slp53.sl.home> schreef in berichtnieuws s5fxz.1213$LR.467@fx17.iad... > >As someone wo has spend quite some time on Windows I'm rather accustomed > >being able to pick a DLL and look inside it to see which functions it > >exposes that I can use (yeah, I still have to generate a library from it and |
| "R.Wieser" <address@not.available>: Aug 30 03:30PM +0200 Scott, > $ man 3 fprintf > Section 1 is commands, 2 is system calls, 3 is library functions, > 4 is device special files, etc. Thanks again. Thats rather usefull (to make an understatement). Regards, Rudy Wieser -- Origional message: Scott Lurndal <scott@slp53.sl.home> schreef in berichtnieuws Cdfxz.1215$LR.777@fx17.iad... > >:-\ I had not thought of that. > >... > >Just tested it, and I had ofcourse (among a few others) to choose a function > >which clashes with a console command : write. :-( :-) Any idea what to do > 5 File formats and conventions eg /etc/passwd > 6 Games > 7 Miscellaneous (including macro packages and conventions), e.g. man(7), groff(7) |
| Ben Bacarisse <ben.usenet@bsb.me.uk>: Aug 30 02:34PM +0100 > and > struct hostent *server; > I regard your above statement true for the first, not the latter. No, the first is a variable (C and C++ call it an object) that holds the structure. The second is an object that holds the address of a struct. > I can tell for the latter "server" is the addres of the variable which holds > the address to the "hostent" structure (hence the need for > dereferencing). If you just want the address of the hostent strict you just write server because that variable already holds the address you want. But the code you showed suggested a different intention: foobar( (unsigned char*) server->h_addr, ... ) This suggest you might want to pass the address of the first member of the list of discovered host addresses: h_addr is a legacy macro that expands to h_addr_list[0]. If that's what you want, then you've got the right code. You don't even need the cast if your function can take a char * argument. But, to repeat, if you just want the address of the whole hostent struct, you already have it in server. <snip> -- Ben. |
| "R.Wieser" <address@not.available>: Aug 30 03:43PM +0200 Jerry, > Does this help? I'm sorry, no. I read the same, and thought I understood. You seem to say that what he wrote works, while the compiler on my machine still throws an compile-time error. I can see that "server->h_addr" and "*server" *should* return the same address. The problem is that I can't get the latter to be accepted (and, as I'm a beginner, assumed I did something wrong), and I have *no* idea why. Do you ? Regards, Rudy Wieser Jerry Stuckle <jstucklex@attglobal.net> schreef in berichtnieuws nq3v9u$sm2$1@jstuckle.eternal-september.org... > >> For dereferencing you need to type '*server' (or 'server->' if you > >> want access particular member of it). > > In my first post I indicated I used the latter using the first member of the > > structure, but I consider that to be a hack. I also indicated that I tried |
| "R.Wieser" <address@not.available>: Aug 30 03:51PM +0200 Scott, > >Odd: several replies, but none that actually told me how its done. Is it > >some deep-dark secret that only masters of the trade are allowed to know ? > Pointers are the most basic of concepts in C, and C++. I should have added the "</sarcasm>" tag, but felt like I would be overdoing it. > Casting your 'server' variable to an unsigned char pointer > is incorrect in either language. Seems to be untrue. The compiler accepts "(unsigned char*) server" without even a warning. Using that result does not seem to cause any problems either. Regards, Rudy Wieser -- Origional message: Scott Lurndal <scott@slp53.sl.home> schreef in berichtnieuws Fgfxz.1216$LR.419@fx17.iad... > >> In short: How do I dereference that "server" variable so > >> the function receives a pointer to the structure ? > >Odd: several replies, but none that actually told me how its done. Is it > >some deep-dark secret that only masters of the trade are allowed to know ? > Pointers are the most basic of concepts in C, and C++. > >And for some of you guys here: don't try to second-guess what I'm after. > >I'm in the habit of trying to ask my questions as exact as I can, needing it > >to have *it* answered. (that does not mean that I do not appreciate further > >Do I really need to waste hours googeling hoping I will stumble over the > >(most likely rather simple) answer ? > If you don't craft your question carefully, you won't get an useful answer. > The question, as originally posted, didn't really make sense in the context |
| Reinhardt Behm <rbehm@hushmail.com>: Aug 30 10:01PM +0800 R.Wieser wrote: > I can see that "server->h_addr" and "*server" should return the same > address. The problem is that I can't get the latter to be accepted (and, > as I'm a beginner, assumed I did something wrong), and I have no idea why. Since we do not know what you function foo accepts as its parameter, we can not really explain it. From what you write it seems it expect a pointer to a char (char*). That would explain that the first form "server->h_addr" is accepted by the compiler. But neither "*server" not "server" is a char pointer. "*server" is a "struct hostent", assuming it has been set correctly and "server" is a pointer to struct hostent. To me it looks as if you do not know that in C (or C++) a pointer is not just an address. It also has the property to point to a certain type. So if your function foo expects a char pointer, meaning it is defined as void foo(char *ptr); You have to call it with a char pointer, not with a pointer to struct anything. This is true even if your variable "server" contains the address (as a bit pattern) of the first byte of some struct hostent which by chance is also the address of char or char array and the address of this char (server- >h_addr) has the same bit pattern it is syntactically some thing different. That willlead to your compiler complaining. One tip: If you think it is to much effort to show something more of your code,then just show us at least the definition of such functions because it not irrelevant. Or show us the compiler message. -- Reinhardt |
| scott@slp53.sl.home (Scott Lurndal): Aug 30 02:48PM >Seems to be untrue. The compiler accepts "(unsigned char*) server" without >even a warning. Using that result does not seem to cause any problems >either. Syntactically, perhaps. Semantically, it's catch as catch can - in this case yours works by luck because the first field in the structure is an array of characters. If you have to cast something explicitly, you're generally doing the wrong thing. struct hostent { char *h_name; /* official name of host */ char **h_aliases; /* alias list */ int h_addrtype; /* host address type */ int h_length; /* length of address */ char **h_addr_list; /* list of addresses */ } struct hostent server; void do_something_with_hostname(char *hostname); do_something_with_hostname(server->h_name); or void do_something_with_hostent(struct hostent *); /* C definition */ void do_something_with_hostent(hostent *); /* C++ definition */ Note that the first field of struct hostent is a pointer to a signed character. For historical reasons all strings in C and C++ are considered to be arrays of signed characters, and the compilers will complain if you attempt to pass server->h_name as the argument of a function that takes 'unsigned char *' as an argument. From the GCC man page (only applies to the C compiler, not the C++ compiler) Ideally, a portable program should always use "signed char" or "unsigned char" when it depends on the signedness of an object. But many programs have been written to use plain "char" and expect it to be signed, or expect it to be unsigned, depending on the machines they were written for. This option, and its inverse, let you make such a program work with the opposite default. |
| Jerry Stuckle <jstucklex@attglobal.net>: Aug 30 11:00AM -0400 On 8/30/2016 9:43 AM, R.Wieser wrote: > I can see that "server->h_addr" and "*server" *should* return the same > address. The problem is that I can't get the latter to be accepted (and, as > I'm a beginner, assumed I did something wrong), and I have *no* idea why. Server->h_addr is a member of the structure. If it is an int, the code will return an int. If it is a double, the code will return a double. If it is an array, it will return the address of the first element in the struct. This will be the same as the address of the struct - but *only if this is the first element in the struct*. Should the struct change at a later time, this will not be true (and will probably cause a very difficult to find bug). > Do you ? > Regards, > Rudy Wieser No, because you haven't shown enough code. If the function takes a type server*, then it should work as I explained. If it takes something else, you shouldn't be passing a server* to it. Function prototypes have a purpose - to indicate what type of parameters the function accepts (and what it returns). Don't try to pass a B when it expects an A. It doesn't work. -- ================== Remove the "x" from my email address Jerry Stuckle jstucklex@attglobal.net ================== |
| legalize+jeeves@mail.xmission.com (Richard): Aug 30 04:31PM [Please do not mail me a copy of your followup] "R.Wieser" <address@not.available> spake the secret code >> Here 'server' is a variable holding the address of a >> 'hostent' structure. server *is* the address. >I'm sorry, but I disagree with you. [...] Then you don't yet understand the fundamentals of the language. Take some on-line courses on C or C++ and learn the fundamentals of pointer types first. -- "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> The Computer Graphics Museum <http://computergraphicsmuseum.org> The Terminals Wiki <http://terminals.classiccmp.org> Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com> |
| legalize+jeeves@mail.xmission.com (Richard): Aug 30 04:33PM [Please do not mail me a copy of your followup] "R.Wieser" <address@not.available> spake the secret code >I'm in the habit of trying to ask my questions as exact as I can, needing it >to have *it* answered. (that does not mean that I do not appreciate further >hints in the same direction though!) Please read "How to Ask Questions the Smart Way": <http://www.catb.org/esr/faqs/smart-questions.html> Your approach is directly at odds with getting the best way of getting help from a programmer oriented newsgroup. -- "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> The Computer Graphics Museum <http://computergraphicsmuseum.org> The Terminals Wiki <http://terminals.classiccmp.org> Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com> |
| jacobnavia <jacob@jacob.remcomp.fr>: Aug 30 07:36PM +0200 Le 30/08/2016 à 08:05, Gareth Owen a écrit : > Actually, none of Jacob's "answers" are the most likely - what he knows > about linux couldn't fill a hat. Doesn't stop him having opinions, of > course. I could say the same thing about you. You do not know anything about me. I have been using linux since at least 1995 or so. But keep your opinion. |
| Manfred <noname@invalid.add>: Aug 30 08:10PM +0200 On 8/30/2016 11:33 AM, R.Wieser wrote: >> the function receives a pointer to the structure ? > Odd: several replies, but none that actually told me how its done. Is it > some deep-dark secret that only masters of the trade are allowed to know ? You had the correct answer, but you appeared to be too much busy attacking the guy who gave you such correct answer in order to get it. > hints in the same direction though!) > Do I really need to waste hours googeling hoping I will stumble over the > (most likely rather simple) answer ? You can't hope to learn C and/or C++ by googleing around. Get a good textbook instead. Besides, many have already already given you the information you asked for. But it looks as if your attitude got you convinced that they were all wrong. Regards, Manfred |
| "R.Wieser" <address@not.available>: Aug 30 07:32PM +0200 Jerry, > No, because you haven't shown enough code. If the > function takes a type server*, then it should work as > I explained Ehrmm .... In my first post in this thread I did show how I call the foobar function, indicating I'm attempting to coerce the provided variable into an unsigned char* before passing it on as the functions argument. If the argument defined in the foobar function itself would be of a different type I would (as far as I know) get a compile-time error because of a mismatch. Hence, the function must look like this: {undefined} foobar(unsigned char* argument , ....) And it does. :-) > Don't try to pass a B when it expects an A. It doesn't work. Agreed. Regards, Rudy Wieser -- Origional message: Jerry Stuckle <jstucklex@attglobal.net> schreef in berichtnieuws nq472u$mg3$1@jstuckle.eternal-september.org... > >> Does this help? > > I'm sorry, no. I read the same, and thought I understood. > > You seem to say that what he wrote works, while the compiler on my machine > > still throws an compile-time error. > > I can see that "server->h_addr" and "*server" *should* return the same > > address. The problem is that I can't get the latter to be accepted (and, as > > I'm a beginner, assumed I did something wrong), and I have *no* idea why. |
| "R.Wieser" <address@not.available>: Aug 30 08:34PM +0200 Richard, > Then you don't yet understand the fundamentals of the language. It could also be that I have a better understanding of what goes on below than you do. You see, you do not seem to understand the difference between a structures address, and a variable *used as* a pointer *to hold* some other variables address. When you say "server *is* the address" you are right. But it is the address of the "server" variable itself, not whatever it addres is stored as its contents. Granted, the language itself makes it easy for you to just forget such fundamental things about it, and just throw something at it to get it silently dereferenced to get at the actual structure. Heck, why do you think both "." and "->" exist to access a strucures fields ? Regards, Rudy Wieser -- Origional message: Richard <legalize+jeeves@mail.xmission.com> schreef in berichtnieuws nq4cdc$c2b$1@news.xmission.com... > pointer types first. > -- > "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> |
| "R.Wieser" <address@not.available>: Aug 30 07:14PM +0200 Scott, > Syntactically, perhaps. Semantically, it's catch as catch > can - in this case yours works by luck because the first > field in the structure is an array of characters. Are you sure about that ? Wait, two things: One: if what you say is true than I should not need to call the function including coercing the "server" variable with "(unsigned char*)" Two: the percieved type of a structure is the same as that of its first field ? ... testing ... Nope on both. The compiler complains about "hostent*" not being compatible to "unsigned char*". And that sound logical to me. > If you have to cast something explicitly, you're generally > doing the wrong thing. Agreed. In this case though its intentional. > struct hostent { [snip] Thanks for the examples. Well, thats something else: The "foobar" routine is not only for that one structure, or for structures only for that matter. Comparable to the "write" function I guess. You can write *any* data with it, as long as you coerce the data's type into the one "write"'s argument expects. And yes, If I would have wanted to use a fields data as its stored in there it stands to reason to receive that field in an argument of the exact same type (ignoring signed/unsigned differences here). Regards, Rudy Wieser -- Origional message: Scott Lurndal <scott@slp53.sl.home> schreef in berichtnieuws s1hxz.19182$IH3.2168@fx40.iad... > "R.Wieser" <address@not.available> writes: > >Scott, > >> >Odd: several replies, but none that actually told me how its done. Is > >it > >> >some deep-dark secret that only masters of the trade are allowed to know > >? > >> Pointers are the most basic of concepts in C, and C++. > >I should have added the "</sarcasm>" tag, but felt like I would be overdoing > >> Casting your 'server' variable to an unsigned char pointer > >> is incorrect in either language. > >Seems to be untrue. The compiler accepts "(unsigned char*) server" without > case yours works by luck because the first field in the structure is > an array of characters. > If you have to cast something explicitly, you're generally doing the wrong thing. > the argument of a function that takes 'unsigned char *' as an > argument. > From the GCC man page (only applies to the C compiler, not the C++ compiler) > Ideally, a portable program should always use "signed char" or "unsigned char" when it depends on > the signedness of an object. But many programs have been written to use plain "char" and expect it > to be signed, or expect it to be unsigned, depending on the machines they were written for. This > option, and its inverse, let you make such a program work with the opposite default. |
| "R.Wieser" <address@not.available>: Aug 30 08:53PM +0200 Manfred, > You had the correct answer, but you appeared to be too > much busy attacking the guy who gave you such correct > answer in order to get it. If the answer was correct, why didn't it work for me ? And pardon me, but I think I have mentioned that at least the first few times. After that ? Yeah, how many times do you think I should be repeating the same answer (to the same suggestions) ? > Besides, many have already already given you the information > you asked for. But it looks as if your attitude got you convinced > that they were all wrong. You mean you didn't notice that I've mentioned a number of times I got a compile-time error when I tried the suggestions ? Are you really trying to shoot the *messenger* here ? I tried *everything* that was suggested. I even retried a number of things I had already done, because maybe I did something wrong the last time (on my own) but *this* time (doing it exactly as suggested) it would work. But there is one thing I simply cannot stand: And that is when I say that something doesn't work the other party keeps insisting that it does <full stop>. Next to that, at the same time not getting any suggestions to what I could try to find the problem (in my understanding or in the code) is not funny either (And no, all that was needed for that was present in the first message). Regards, Rudy Wieser Manfred <noname@invalid.add> schreef in berichtnieuws nq4i5q$ofh$1@gioia.aioe.org... > >> In short: How do I dereference that "server" variable so > >> the function receives a pointer to the structure ? > > Odd: several replies, but none that actually told me how its done. Is it > > some deep-dark secret that only masters of the trade are allowed to know ? > attacking the guy who gave you such correct answer in order to get it. > > And for some of you guys here: don't try to second-guess what I'm after. > > I'm in the habit of trying to ask my questions as exact as I can, needing it > > to have *it* answered. (that does not mean that I do not appreciate further > You can't hope to learn C and/or C++ by googleing around. Get a good > textbook instead. > Besides, many have already already given you the information you asked for. > But it looks as if your attitude got you convinced that they were all wrong. |
| "R.Wieser" <address@not.available>: Aug 30 05:01PM +0200 Chris, > 19:16:59 UTC). 'server', as in: > struct hostent *server; > is declared as a pointer and can be passed as a pointer. And I've told this group several times that IT DOESN'T WORK. You can keep giving me the same "this should work" as many times as you like, but my compiler is rather uninpressed by this against-the-facts insistance, laughs about it a bit and just keeps throwing the compile-time error. :-\ I do wish you guys could convince him otherwise though. :-) > _is_ a pointer. You only need to dereference it if you want > to obtain the structure's members. There is no secret here. > It is the most basic C. Absolutily. So, why don't you tell me why "server->h_addr" works, but "*server" won't ? > "a novice in regard to using C++ (GCC) *and* using linux" > people thought that it was the specific gcc and linux issues > you were unfamiliar with, not the basics of C and C++ itself. Irrelevant. I think the question is clear enough. Regardless of if its a high-level problem, or one as basic as this one. Heck, as its a problem that has to do with "the basics of C and C++ itself" *everyone* here (above the novice level) should know what to do about it, don't you think ? > You gave the impression that you had done some > windows programming. I have. I didn't mention which language though. :-) I mentioned to indicate that I'm no stranger to the logic of programming, or its syntax. That does not mean I know everything, or cannot run into stupid "you have to do it exactly *this* way" problems when encountering a new language. > The other difficulty is that you have an attitude problem > which is considerably larger than your state of knowledge; You think *I* have an attitude problem, when being confronted with a slew of people who do not read (advising me to try stuff I wrote already I did), and do not take "No, it doesn't work" for an answer ? You must be joking. :-| > this [attitude] is going to get you into trouble, both in your code That "in your code" I do not quite understand. My code has no problem with who I am, what I look like or how many keyboards I go thru in an average session. :-) > and in your interactions on this news group. True. But I don't mind to get rid of people who only know one answer, and keep repeating that same answer over-and-over again because they simply refuse to accept that it doesn't work. *That* attitude is simply infuriating. ... and I guess that my getting "rather annoyed" shows in my answers. :-) :-\ But please do explain why "server->h_addr" works, but "*server" not. I could really use it. If it simply doesn't (for whatever reason) I will be content too (though you stand a chance that I will say "Ha! Told you so!" to several of this threads contributors. Sorry.) Regards, Rudy Wieser P.s. I think I gave enough code in my first post to reproduce the problem. Currently I have not heard of anyone trying and either having a pro or con experience. Odd. -- Origional message: Chris Vine <chris@cvine--nospam--.freeserve.co.uk> schreef in berichtnieuws 20160830135918.3d0861d6@dell.homenet... |
| Lynn McGuire <lynnmcguire5@gmail.com>: Aug 30 12:24PM -0500 On 8/29/2016 1:52 PM, Daniel wrote: > I think the Unicode people have vastly simplified many people's lives. > Admittedly, C++ has badly screwed this up. > Daniel Microsoft has a big hand in the screw up with their decision to go with wide characters. But the Unicode consortium is getting wacky here lately with adding emoticons to Unicode. http://blog.unicode.org/2016/06/unicode-90-emoji-available-for-adoption.html Lynn |
| legalize+jeeves@mail.xmission.com (Richard): Aug 30 06:50PM [Please do not mail me a copy of your followup] >On 8/29/2016 1:52 PM, Daniel wrote: >> Admittedly, C++ has badly screwed this up. I think you have your history backwards. C and C++ predate unicode. The general consensus seems to be that you should use std::string with UTF-8 encoding to add basic unicode support. You can always get fancier if you need it with Qt, wxWidgets, UCS, etc. -- "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> The Computer Graphics Museum <http://computergraphicsmuseum.org> The Terminals Wiki <http://terminals.classiccmp.org> Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com> |
| mark <mark@invalid.invalid>: Aug 30 05:23PM +0200 On 2016-08-30 13:28, Chris Vine wrote: > T t2 = c->t; // this is all you can do with C > But there may be something else in the standard which precludes even > this. My reading of the standard is that this works if C (and all its members) has a trivial default constructor. If not, it's undefined behavior. If C has a trivial default constructor, storage allocation is enough to start the lifetime, otherwise a constructor has to run. §3.08/5 Object lifetime: <<< Before the lifetime of an object has started but after the storage which the object will occupy has been allocated or, after the lifetime of an object has ended and before the storage which the object occupied is reused or released, any pointer that refers to the storage location where the object will be or was located may be used but only in limited ways. [...] Indirection through such a pointer is permitted but the resulting lvalue may only be used in limited ways, as described below. The program has undefined behavior if: [...] - the pointer is used to access a non-static data member or call a non-static member function of the object, or [...] |
| You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to comp.lang.c+++unsubscribe@googlegroups.com. |
No comments:
Post a Comment