| Gareth Owen <gwowen@gmail.com>: Aug 30 07:05AM +0100 >> find multiple (sometimes over 10) same-named header files , most often of >> different sizes. Whats the idea behind that, and how should I know which >> one of those to include ? The compiler knows, so you don't have to. If you want to include stdio.h, use #include <stdio.h> > Ahhh welcome to linux. Actually there is no way to know. There are lots of ways to know. The package manager will know, > You can have different headers if you have installed different > compilers or different versions of the same compiler, or just some > hacks that didn't go well and left some headers... who knows? Ask the package manager. The package manager knows. 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. The most likely answer is that they all belong to one compiler. On my system I have /usr/include/stdio.h /usr/include/c++/4.8/tr1/stdio.h /usr/include/x86_64-linux-gnu/bits/stdio.h all of which belong to the gcc version I have installed. (I also have the ARM-versions for the ARM compiler, in folders with names like arm-xilinx-eabi). When I do #include <stdio.h> the compiler does the right thing. |
| "R.Wieser" <address@not.available>: Aug 30 11:12AM +0200 jacobnavia, >Ahhh welcome to linux. Actually there is no way to know. ... > Now, you can ask the compiler which headers is it using, if > memory serves gcc had a command line option to show the > paths its using. Ah, that makes some sense. I seem to remember having seen something like that (a reference to a cache of some sort). Thanks for the hint. Regards, Rudy Wieser -- Origional message: jacobnavia <jacob@jacob.remcomp.fr> schreef in berichtnieuws nq28u0$al3$1@dont-email.me... > Le 29/08/2016 à 21:16, R.Wieser a écrit : > > And now I'm on a roll asking questions, one thing I did not expect was to > > find multiple (sometimes over 10) same-named header files , most often of > > different sizes. Whats the idea behind that, and how should I know which |
| "R.Wieser" <address@not.available>: Aug 30 10:57AM +0200 Paavo, > Anyway, if you have troubles with basic syntax like this, > then I suggest to start with a proper textbook or tutorial. Thanks, but al you seem to be saying is "go away". Thanks bub. Is it really so hard to dereference something that it can't be described in few lines ? > But anyway, first google search shows there are things > like objdump and readelf which might be useful for > examining so-s. Using 20-20 vision, sure. Mind you, I gave you a fair warning that I'm a *beginner* (at least in respect to Linux and C{something} ). I *assume* that library files are the .o files in the "lib" branch, but am not even sure about that. Also, how do you think I found that "nm" I spoke of ? Regards, Rudy Wieser -- Origional message: Paavo Helde <myfirstname@osa.pri.ee> schreef in berichtnieuws vvidnecFA7cvB1nKnZ2dnUU78QXNnZ2d@giganews.com... > On 29.08.2016 22:16, R.Wieser wrote: > > Hello all, > > Fair warning: I'm a novice in regard to using C++ (GCC) *and* using linux > > (lubuntu to be exact). If this is not the newsgroup to be asking questions > > - - - - - - > > First problem, C++ related: > > I need to transfer the address of a structure to a function, and have only > > be able to find a hackish solution for it. The problem is that the variable > > I've got is actually a pointer, and I have no idea how to dereference it. > > server = gethostbyname(argv[1]); > > Now I want to transfer the address stored in the "server" variable to a > > function. The only way I was able to do that was to refer to the first (and > > 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 > > To be honest, I have no idea if the above is even feasible for C++ (GCC) > > under linux. > > I did find an example using "nm", but that only showed the contents of the > man fprintf > for example. > > And now I'm on a roll asking questions, one thing I did not expect was to > > find multiple (sometimes over 10) same-named header files , most often of > > different sizes. Whats the idea behind that, and how should I know which |
| "R.Wieser" <address@not.available>: Aug 30 10:43AM +0200 嘱 Tiib, > Yes, but it seemed that he wanted host addresses as strings > from that hostent structure. Nope, I just want the address of the structure itself. Thats all. > it is not clear what programming language I'm not sure myself, but I assume that its C++, seeing that let G++ compile the sourcecode. > and in what way he used on Windows. I didn't. I'm doing it on a Linux variant. Regards, Rudy Wieser -- Origional message 嘱 Tiib <ootiib@hot.ee> schreef in berichtnieuws 242b3c44-f5a2-4bed-b019-447827e5f856@googlegroups.com... > > "R.Wieser" <address@not.available> spake the secret code > > <57c4895a$0$871$e4fe514c@news.xs4all.nl> thusly: > > >I need to transfer the address of a structure to a function, and have only > > >be able to find a hackish solution for it. The problem is that the variable > > >I've got is actually a pointer, and I have no idea how to dereference it. |
| "R.Wieser" <address@not.available>: Aug 30 10:31AM +0200 Andy, > As someone who started using Linux not many years ago > after many years of other systems, which included a _lot_ > of Windows - I've almost never had to do that on Windows :-) Who said I was using C{something} on Windows :-p But consider my request both as an attempt to get a bit more knowledge about how stuff works, as well as creating independance from the "they" that should make the header and library files for me. But, in the first place its only an attempt to generate a list with all available functions that I can use in a program. Currently the only way to know if a certain function (that I know exists in Windows) is available in gcc/linux is by stumbling over it in an example program. And that isn't acceptable to me. Regards, Rudy Wieser -- Origional message: Vir Campestris <vir.campestris@invalid.invalid> schreef in berichtnieuws 4vSdnVhKxMTWCFnKnZ2dnUU78afNnZ2d@brightview.co.uk... > > 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 10:09AM +0200 Richard, > Here 'server' is a variable holding the address of a > 'hostent' structure. server *is* the address. I'm sorry, but I disagree with you. Just consider the difference between struct hostent server; and struct hostent *server; I regard your above statement true for the first, not the latter. As far as 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). Regards, Rudy Wieser -- Origional message: Richard <legalize+jeeves@mail.xmission.com> schreef in berichtnieuws nq21nb$ead$1@news.xmission.com... > "R.Wieser" <address@not.available> spake the secret code > <57c4895a$0$871$e4fe514c@news.xs4all.nl> thusly: > >I need to transfer the address of a structure to a function, and have only > >be able to find a hackish solution for it. The problem is that the variable > "server is a pointer to a hostent structure" > -- > "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> |
| "R.Wieser" <address@not.available>: Aug 30 11:17AM +0200 Gareth, > The compiler knows, so you don't have to. If you want > to include stdio.h, use > #include <stdio.h> Thats exactly the problem. How do I know that I need to include stdio.h and not foobar.h to be able to use a certain function ? > There are lots of ways to know. The package manager will know, What has the packet manager to do with anything ? *I'm* writing a program, and *I* need to add the correct includes. Regards, Rudy Wieser - Origional message: Gareth Owen <gwowen@gmail.com> schreef in berichtnieuws 87wpiyokq8.fsf@gmail.com... > jacobnavia <jacob@jacob.remcomp.fr> writes: > > Le 29/08/2016 à 21:16, R.Wieser a écrit : > >> And now I'm on a roll asking questions, one thing I did not expect was to > >> find multiple (sometimes over 10) same-named header files , most often of > >> different sizes. Whats the idea behind that, and how should I know which |
| Ian Collins <ian-news@hotmail.com>: Aug 30 09:19PM +1200 On 08/30/16 09:17 PM, R.Wieser wrote: >> #include <stdio.h> > Thats exactly the problem. How do I know that I need to include stdio.h and > not foobar.h to be able to use a certain function ? man <certain function> -- Ian |
| "R.Wieser" <address@not.available>: Aug 30 11:33AM +0200 Funny: > 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 ? 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 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 ? Regards, Rudy Wieser |
| Paavo Helde <myfirstname@osa.pri.ee>: Aug 30 12:38PM +0300 On 30.08.2016 11:57, R.Wieser wrote: >> Anyway, if you have troubles with basic syntax like this, >> then I suggest to start with a proper textbook or tutorial. > Thanks, but al you seem to be saying is "go away". Thanks bub. I'm just saying that it is not productive to learn language basics from a newsgroup, it's too tedious and chaotic. If you get stuck with some more concrete problem then you can always come back here, and preferably with a real code sample, not a vague description using wrong terms. > Is it really so hard to dereference something that it can't be described in > few lines ? You wanted to get a pointer, that's basically the opposite of dereferencing. Besides, your original question was answered immediately by Richard so there was no need to repeat this answer. If you have a pointer called 'server', then for dereferencing it you use '*server' or 'server->', depending on the exact usage. For passing the pointer without dereferencing you just use 'server'. > *beginner* (at least in respect to Linux and C{something} ). I *assume* > that library files are the .o files in the "lib" branch, but am not even > sure about that. No, library files are called .so and .a. I'm sorry I mentioned objdump and readelf, I should have just said that examining the library symbols is a rare need and definitely not something a beginner should do at all. Cheers Paavo |
| Paavo Helde <myfirstname@osa.pri.ee>: Aug 30 12:44PM +0300 On 30.08.2016 12:17, R.Wieser wrote: >> #include <stdio.h> > Thats exactly the problem. How do I know that I need to include stdio.h and > not foobar.h to be able to use a certain function ? From the function documentation of course. How else could you know how to use the function at all? If you want to use fprintf, then type man fprintf in the Linux command line or google search and the correct #include is among the first things it says: fprintf(3) - Linux man page Name printf, fprintf, sprintf, snprintf, vprintf, vfprintf, vsprintf, vsnprintf - formatted output conversion Synopsis #include <stdio.h> int printf(const char *format, ...); int fprintf(FILE *stream, const char *format, ...); NRHTH Paavo |
| "Öö Tiib" <ootiib@hot.ee>: Aug 30 03:55AM -0700 On Tuesday, 30 August 2016 12:14:44 UTC+3, R.Wieser wrote: > I regard your above statement true for the first, not the latter. As far as > 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). Unfortunately you seem to add one indirection that isn't there. In former 'server' is variable that contains all data of structure 'hostent'. To get address to it you need to type '&server'. In latter 'server' is pointer variable that can contain address of structure 'hostent'. When it is pointing at actual 'hostent' then you may dereference it. For dereferencing you need to type '*server' (or 'server->' if you want access particular member of it). |
| "R.Wieser" <address@not.available>: Aug 30 01:34PM +0200 Paavo, > 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. > If you get stuck with some more concrete problem ... I don't know how much more concrete it can become as what I described. But maybe the following problem casing will help you: two definitions: 1) struct hostent server1; 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 type unsigned char*. Describe the calling method for *both*. (I'm rather sure that my answer lies in the difference between the two). Concrete enough for you ? > 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 what "code samples" look like in your reality. > ... using wrong terms. See below: > You wanted to get a pointer, that's basically the opposite of > dereferencing. And you talk about vague ? Yes, I want to "get a pointer". But I want to move *towards* the structure, not *away* from it. And as far as I'm aware thats indeed called "dereferencing" > Besides, your original question was answered immediately > by Richard so there was no need to repeat this answer. Bull. And if you think otherwise than quote it. All he did was quoting the first line of my code sample. Yeah, thats really helpfull. Not. > then for dereferencing it you use '*server' or 'server->', > depending on the exact usage Also bull. Both foobar( (unsigned char*) *server , ... ) as well as foobar( (unsigned char*) server-> , ... ) throw a compile-time error (invalid cast for the first, unqualified identifier for the second). And FYI, I have tried the former before posting here (didn't think the latter having any chance of succeeding, so I didn't even try it). > No, library files are called .so and .a. Thanks. So, I was looking in the wrong files. That could explain a lot. :-) Regards, Rudy Wieser -- Origional message: Paavo Helde <myfirstname@osa.pri.ee> schreef in berichtnieuws _LidnQTXd5SPyVjKnZ2dnUU78LPNnZ2d@giganews.com... > more concrete problem then you can always come back here, and preferably > with a real code sample, not a vague description using wrong terms. > > Is it really so hard to dereference something that it can't be described in > >> like objdump and readelf which might be useful for > >> examining so-s. > > Using 20-20 vision, sure. Mind you, I gave you a fair warning that I'm a > > *beginner* (at least in respect to Linux and C{something} ). I *assume* |
| "R.Wieser" <address@not.available>: Aug 30 01:48PM +0200 Ian, > man <certain function> :-\ 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 in such cases ? Regards, Rudy Wieser -- Origional message: Ian Collins <ian-news@hotmail.com> schreef in berichtnieuws e2l1dgFec6gU3@mid.individual.net... > >> to include stdio.h, use > >> #include <stdio.h> > > Thats exactly the problem. How do I know that I need to include stdio.h and |
| Paavo Helde <myfirstname@osa.pri.ee>: Aug 30 02:57PM +0300 On 30.08.2016 14:34, R.Wieser wrote: >> 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. > structure to a function called "foobar", which expects the argument to be of > type unsigned char*. > Concrete enough for you ? Yes, that was concrete enough, thank you. Here are the answers to these questions. 1) foobar(reinterpret_cast<unsigned char*>(&server1)); 2) foobar(reinterpret_cast<unsigned char*>(server2)); (side note: this is C++ so you probably need to compile it with g++, not gcc). (side note 2: there is no dereferencing here, & is the address-of operator. The term "dereferencing" has very specific meaning in C and C++ and if you use it in a C or C++ forum everybody assumes you are 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 > what "code samples" look like in your reality. A proper code sample is preferably a complete source file including all the #includes as well as int main(). This makes it easy for other people to try to compile it and understand where the problems appear. See e.g. https://groups.google.com/forum/#!topic/comp.lang.c++/VaDCk_oujMg |
| "R.Wieser" <address@not.available>: Aug 30 02:01PM +0200 嘱 Tiib, > In former 'server' is variable that contains all data of structure > 'hostent'. To get address to it you need to type '&server'. Agreed. > In latter 'server' is pointer variable that can contain address > of structure 'hostent'. Again, agreed. > When it is pointing at actual 'hostent' then you may dereference it. YES. How do I do that ? > 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 "(*server)", and that it gave me a compile-time error. Any other ideas ? Regards, Rudy Wieser -- Origional message: 嘱 Tiib <ootiib@hot.ee> schreef in berichtnieuws 6fe758df-bf42-430f-be92-88c7455378f3@googlegroups.com... > > > Here 'server' is a variable holding the address of a > > > 'hostent' structure. server *is* the address. > > I'm sorry, but I disagree with you. Just consider the difference between > > and > > struct hostent *server; > > I regard your above statement true for the first, not the latter. As far as > > 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). > 'server' is variable that contains all data of structure 'hostent'. To get > address to it you need to type '&server'. > In latter 'server' is pointer variable that can contain address of structure > 'hostent'. When it is pointing at actual 'hostent' then you may dereference it. > For dereferencing you need to type '*server' (or 'server->' if you want access |
| scott@slp53.sl.home (Scott Lurndal): Aug 30 12:36PM >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 >find the function declarations, but thats not the point). $ nm -D /usr/lib64/libzip.so.2 | grep " T " |more |
| scott@slp53.sl.home (Scott Lurndal): Aug 30 12:42PM >> #include <stdio.h> >Thats exactly the problem. How do I know that I need to include stdio.h and >not foobar.h to be able to use a certain function ? The man pages are your friend. $ man -k printf asprintf (3) - print to allocated string dprintf (3) - print to a file descriptor format (n) - Format a string in the style of sprintf fprintf (3) - formatted output conversion fprintf (3p) - print formatted output fwprintf (3) - formatted wide-character output conversion fwprintf (3p) - print formatted wide-character output printf (1) - format and print data printf (1p) - write formatted output printf (3) - formatted output conversion printf (3p) - print formatted output snprintf (3) - formatted output conversion snprintf (3p) - print formatted output sprintf (3) - formatted output conversion sprintf (3p) - print formatted output swprintf (3) - formatted wide-character output conversion ... $ 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 SYNOPSIS #include <stdio.h> int printf(const char *format, ...); int fprintf(FILE *stream, const char *format, ...); int sprintf(char *str, const char *format, ...); int snprintf(char *str, size_t size, const char *format, ...); #include <stdarg.h> int vprintf(const char *format, va_list ap); int vfprintf(FILE *stream, const char *format, va_list ap); int vsprintf(char *str, const char *format, va_list ap); Or you can use the appropriate standard document, for example: http://pubs.opengroup.org/onlinepubs/9699919799/functions/fprintf.html |
| scott@slp53.sl.home (Scott Lurndal): Aug 30 12:45PM >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 >in such cases ? If you don't already know what manual section it is in, use man -k to find all the relevent pages: $ man -k fprintf asprintf (3) - print to allocated string dprintf (3) - print to a file descriptor format (n) - Format a string in the style of sprintf fprintf (3) - formatted output conversion fprintf (3p) - print formatted output fwprintf (3) - formatted wide-character output conve Then use the section number: $ man 3 fprintf Section 1 is commands, 2 is system calls, 3 is library functions, 4 is device special files, etc. 1 Executable programs or shell commands 2 System calls (functions provided by the kernel) 3 Library calls (functions within program libraries) 4 Special files (usually found in /dev) 5 File formats and conventions eg /etc/passwd 6 Games 7 Miscellaneous (including macro packages and conventions), e.g. man(7), groff(7) 8 System administration commands (usually only for root) 9 Kernel routines [Non standard] |
| 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 ================== |
| scott@slp53.sl.home (Scott Lurndal): Aug 30 12:48PM >> 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++. >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 ? 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 of C or C++ programming. Casting your 'server' variable to an unsigned char pointer is incorrect in either language. |
| Piotr Wyderski <piotr.wyderski.no.spam@gmail.com>: Aug 30 09:25AM +0200 Paavo Helde wrote: > T*' are already non-portable enough so that additional cast to const C* > would probably be the safest step here (assuming standard layout, T as > the first member and equal sizeof-s). Yes, you understood the use case correctly. It is all about bulk loading -- I want to load a big chunk of disk data (not even memory-mapping the file, full-blown asynchronous IO operations will be used instead) and then apply some non-mutating operations on this array of Ts as if it were an array of Cs. In the moment of content creation it was an array of Cs, so technically it is a sequence of reinterpret_casts C[]=>T[]=>C[], which just happened in different runs of the same program. The content does not have to be portable, it will never leave the machine. I just wanted it to be as C++-conforming as possible. Since C++ appears to know something about the standard_layout peculiarities, it seems doable without excessive violations of the standard. Best regards, Piotr |
| "Öö Tiib" <ootiib@hot.ee>: Aug 30 03:30AM -0700 On Tuesday, 30 August 2016 10:26:08 UTC+3, Piotr Wyderski wrote: > Since C++ appears to know something about the standard_layout > peculiarities, it seems doable without excessive violations of the standard. > Best regards, Piotr Add something like that into code after that struct C is defined: static_assert( std::is_standard_layout<C>::value && std::is_arithmetic<T>::value && std::is_same<T, decltype(C::t)>::value && sizeof (T[42]) == sizeof (C[42]) , "need to cast between T[] and C[]" ); That double-checks the situation in paranoid manner and so documents why it is important and makes sure that some future maintenance does not accidentally break it. Files on disk tend to live longer than versions of software. |
| Chris Vine <chris@cvine--nospam--.freeserve.co.uk>: Aug 30 12:28PM +0100 On Tue, 30 Aug 2016 09:25:59 +0200 > C++-conforming as possible. Since C++ appears to know something about > the standard_layout peculiarities, it seems doable without excessive > violations of the standard. This looks like a very bad idea. If what you have committed to disk is a binary representation of an array of T objects of some kind, you cannot recreate your C objects from this in a portable fashion because the C objects no longer exist. You could only do the reverse portably. The operative word is "portably" - if sizeof C is the same as sizeof T you will probably get away with it. By virtue of the sixth bullet of §3.10/10 read with §9.2/20, given a type T which enables struct C { T t; int i;}; to be both an aggregate and a standard layout struct, and an object of type T: T t; what you can do on my reading of the standard is this: C* c = reinterpret_cast<C*>(&t); // OK so far, but be very afraid 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. Obviously this would not allow you to treat your array of T objects as if it were an array of C objects. The correct thing to do is to deal with your T objects as T objects. Chris |
| Mr Flibble <flibbleREMOVETHISBIT@i42.co.uk>: Aug 30 02:39AM +0100 int main(int argc, char* argv[]) { /* Introducing "indexitor", a new C++ container... */ std::vector<int> v; for (int i = 0; i < 15; ++i) v.push_back(i + 700); neolib::indexitor<std::string, std::size_t> idx; idx.push_back(std::make_pair("first", 5)); idx.push_back(std::make_pair("second", 5)); idx.push_back(std::make_pair("third", 5)); /* idx is holding three elements which map to first 5, second 5 and third 5 elements respectively of a foreign container. */ /* Now for primary use-case: modify foreign container: */ v.erase(v.begin() + 2); // remove third element auto ii = idx.begin(); idx.update_foreign_index(idx.begin(), 5 - 1); // update indexitor for (std::size_t i = 0; i < v.size(); ++i) std::cout << i << ": " << idx.find_by_foreign_index(i)->first << " -> " << v[i] << std::endl; /* All indexitor index/update operations are worst-case O(lg N) complexity. */ } Output: 0: first -> 700 1: first -> 701 2: first -> 703 3: first -> 704 4: second -> 705 5: second -> 706 6: second -> 707 7: second -> 708 8: second -> 709 9: third -> 710 10: third -> 711 11: third -> 712 12: third -> 713 13: third -> 714 Download (at own risk as not yet fully tested) from: https://github.com/FlibbleMr/neolib |
| 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