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diff --git a/libstdc++-v3/docs/faq/index.html b/libstdc++-v3/docs/faq/index.html new file mode 100644 index 0000000..12c7b3d --- /dev/null +++ b/libstdc++-v3/docs/faq/index.html @@ -0,0 +1,672 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN"> +<HTML> +<HEAD> + <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> + <META NAME="AUTHOR" CONTENT="pme@sourceware.cygnus.com (Phil Edwards)"> + <META NAME="KEYWORDS" CONTENT="libstdc++, libstdc++-v3, egcs, g++, libg++, STL"> + <META NAME="DESCRIPTION" CONTENT="FAQ for the GNU libstdc++ effort."> + <META NAME="GENERATOR" CONTENT="vi and eight fingers"> + <TITLE>libstdc++-v3 FAQ</TITLE> +<LINK REL="home" HREF="http://sourceware.cygnus.com/libstdc++/"> +<LINK REL=StyleSheet HREF="../lib3styles.css"> +<!-- + ** Locations of "the most recent snapshot is the Nth" text are + ** answers 1_1, 1_4, 4_1, 5_6. +--> +<!-- $Id: index.html,v 1.21 2000/03/26 03:44:35 pme Exp $ --> +</HEAD> +<BODY> + +<H1 CLASS="centered">libstdc++ Frequently Asked Questions</H1> + +<P>The latest version of this document is always available at +<A HREF="http://sourceware.cygnus.com/libstdc++/faq/index.html"> +http://sourceware.cygnus.com/libstdc++/faq/</A>.</P> + +<P>To the <A HREF="../index.html">libstdc++-v3 homepage</A>. + +<!-- ####################################################### --> +<HR> +<H1>Questions</H1> +<OL> + <LI><A HREF="#1_0">General Information</A> + <!-- I suspect these will mostly be links to/into existing documents. --> + <OL> + <LI><A HREF="#1_1">What is libstdc++-v3?</A> + <LI><A HREF="#1_2">Why should I use libstdc++?</A> + <LI><A HREF="#1_3">Who's in charge of it?</A> + <LI><A HREF="#1_4">How do I get libstdc++?</A> + <LI><A HREF="#1_5">When is libstdc++ going to be finished?</A> + <LI><A HREF="#1_6">How do I contribute to the effort?</A> + <LI><A HREF="#1_7">What happened to libg++? I need that!</A> + <LI><A HREF="#1_8">What if I have more questions?</A> + </OL> + + <LI><A HREF="#2_0">Installation</A> + <OL> + <LI><A HREF="#2_1">How do I install libstdc++-v3?</A> + <LI><A HREF="#2_2">Is this a drop-in replacement for the + libstdc++ that's shipped with g++?</A> + <LI><A HREF="#2_3">What is this CVS thing that you keep + mentioning?</A> + <LI><A HREF="#2_4">How do I know if it works?</A> + </OL> + + <LI><A HREF="#3_0">Platform-Specific Issues</A> + <OL> + <LI><A HREF="#3_1">Can libstdc++-v3 be used with <my + favorite compiler>?</A> + <LI><A HREF="#3_2">Building under Cygwin hangs/explodes!?</A> + </OL> + + <LI><A HREF="#4_0">Known Bugs and Non-Bugs</A> + <OL> + <LI><A HREF="#4_1">What works already?</A> + <LI><A HREF="#4_2">Bugs in gcc/g++ (not libstdc++-v3)</A> + <LI><A HREF="#4_3">Bugs in the C++ language/lib specification</A> + <LI><A HREF="#4_4">Things in libstdc++ that look like bugs</A> + <LI><A HREF="#4_5">Aw, that's easy to fix!</A> + </OL> + + <LI><A HREF="#5_0">Miscellaneous</A> + <OL> + <LI><A HREF="#5_1">string::iterator is not char*; + vector<T>::iterator is not T*</A> + <LI><A HREF="#5_2">What's next after libstdc++-v3?</A> + <LI><A HREF="#5_3">What about the STL from SGI?</A> + <LI><A HREF="#5_4">Extensions and Backward Compatibility</A> + <LI><A HREF="#5_5">Compiling with "-fnew-abi"</A> + <LI><A HREF="#5_6">Is libstdc++-v3 thread-safe?</A> + <LI><A HREF="#5_7">How do I get a copy of the ISO C++ Standard?</A> + </OL> + +</OL> + +<HR> + +<!-- ####################################################### --> + +<H1><A NAME="1_0">1.0 General Information</A></H1> +<!-- I suspect these will mostly be links to/into existing documents. --> + <H2><A NAME="1_1">1.1 What is libstdc++-v3?</A></H2> + <P>The GNU Standard C++ Library v3, or libstdc++-2.90.x, is an + ongoing project to implement the ISO 14882 Standard C++ library + as described in chapters 17 through 27 and annex D. As the + library reaches stable plateaus, it is captured in a snapshot + and released. The current release is <A +HREF="ftp://sourceware.cygnus.com/pub/libstdc++/libstdc++-2.90.8.tar.gz">the + ninth snapshot</A>. For those who want to see exactly how + far the project has come, or just want the latest + bleeding-edge code, the up-to-date source is available over + anonymous CVS, and can even be browsed over the Web (see below). + </P> + <P>A more formal description of the V3 goals can be found in the + official <A HREF="../17_intro/DESIGN">design document</A>. + </P> + +<HR> + <H2><A NAME="1_2">1.2 Why should I use libstdc++?</A></H2> + <P>The recent completion of the ISO C++ standardization gave the + C++ community a powerful set of reuseable tools in the form + of the C++ Standard Library. However, all existing C++ + implementations are (as the Draft Standard used to say) + "incomplet and incorrekt," and many suffer from + limitations of the compilers that use them. + </P> + <P>The GNU C/C++/FORTRAN/<pick-a-language> compiler + (<TT>gcc</TT>, <TT>g++</TT>, etc) is widely considered to be + one of the leading compilers in the world. Its development + has recently been taken over by the + <A HREF="http://egcs.cygnus.com/">GCC team</A>. All of + the rapid development and near-legendary + <A +HREF="http://egcs.cygnus.com/gcc-2.95/buildstat.html">portability</A> + that are the hallmarks of an open-source project are being + applied to libstdc++. + </P> + <P>That means that all of the Standard classes and functions + (such as <TT>string</TT>, <TT>vector<></TT>, iostreams, + and algorithms) will be freely available and fully compliant. + Programmers will no longer need to "roll their own" + nor be worried about platform-specific incompatabilities. + </P> + +<HR> + <H2><A NAME="1_3">1.3 Who's in charge of it?</A></H2> + <P>The libstdc++ project is contributed to by several developers + all over the world, in the same way as GCC (EGCS) or Linux. + Benjamin Kosnik, Gabriel Dos Reis, Nathan Myers, and Ulrich + Drepper are the lead maintainers of the CVS archive. + </P> + <P>Development and discussion is held on the libstdc++ mailing + list. Subscribing to the list, or searching the list + archives, is open to everyone. You can read instructions for + doing so on the <A HREF="../index.html">homepage</A>. If you + have questions, ideas, code, or are just curious, sign up! + </P> + +<HR> + <H2><A NAME="1_4">1.4 How do I get libstdc++?</A></H2> + <P>The ninth (and latest) snapshot of libstdc++-v3 is <A +HREF="ftp://sourceware.cygnus.com/pub/libstdc++/libstdc++-2.90.8.tar.gz"> + available via ftp</A>. + </P> + <P>The <A HREF="../index.html">homepage</A> + has instructions for retrieving the latest CVS sources, and for + browsing the CVS sources over the web. + </P> + <P>The subset commonly known as the Standard Template Library + (chapters 23 through 25, mostly) is adapted from the SGI STL, + which is also an ongoing work.<!-- Possibly a link to SGI's + STL here. --> + </P> + +<HR> + <H2><A NAME="1_5">1.5 When is libstdc++ going to be finished?</A></H2> + <P>Nathan Myers gave the best of all possible answers in <A + HREF="http://www.deja.com/getdoc.xp?AN=469581698&fmt=text">a + recent Usenet article</A>.</P> + +<HR> + <H2><A NAME="1_6">1.6 How do I contribute to the effort?</A></H2> + <P>Here is <A HREF="../17_intro/contribute.html">a + page devoted to this topic</A>. Subscribing to the mailing + list (see above, or the homepage) is a very good idea if you + have something to contribute, or if you have spare time and + want to help. Contributions don't have to be in the form of + source code; anybody who is willing to help write + documentation, for example, or has found a bug in code that + we all thought was working, is more than welcome! + </P> + +<HR> + <H2><A NAME="1_7">1.7 What happened to libg++? I need that!</A></H2> + <P>The most recent libg++ README states that libg++ is no longer + being actively maintained. It should not be used for new + projects, and is only being kicked along to support older code. + </P> + <P>The libg++ was designed and created when there was no Standard + to provide guidance. Classes like linked lists are now provided + for by <TT>list<T></TT> and do not need to be created by + <TT>genclass</TT>. (For that matter, templates exist now and + are well-supported, whereas genclass (mostly) predates them.) + </P> + <P>There are other classes in libg++ that are not specified in the + ISO Standard (e.g., statistical analysis). While there are a + lot of really useful things that are used by a lot of people + (e.g., statistics :-), the Standards Committee couldn't include + everything, and so a lot of those "obvious" classes + didn't get included. + </P> + <P>Since libstdc++ is an implementation of the Standard Library, we + have no plans at this time to include non-Standard utilities + in the implementation, however handy they are. (The extensions + provided in the SGI STL aren't maintained by us and don't get + a lot of our attention, because they don't require a lot of our + time.) It is entirely plausable that the "useful stuff" + from libg++ might be extracted into an updated utilities library, + but nobody has stated such a project yet. + </P> + <!-- The advertisement, so to speak, might have to go. Hmmmmm. --> + <P>(The <A HREF="http://www.boost.org/">Boost</A> site houses free + C++ libraries that do varying things, and happened to be started + by members of the Standards Committee. Certain "useful + stuff" classes will probably migrate there.) + </P> + <P>For the bold and/or desperate, the + <A HREF="http://egcs.cygnus.com/faq.html#libg++">GCC FAQ</A> + describes where to find the last libg++ source. + </P> + +<HR> + <H2><A NAME="1_8">1.8 What if I have more questions?</A></H2> + <P>If you have read the README and RELEASE-NOTES files, and your + question remains unanswered, then just ask the mailing list. + At present, you do not need to be subscribed to the list to + send a message to it. More information is available on the + homepage (including how to browse the list archives); to send + to the list, use <A HREF="mailto:libstdc++@sourceware.cygnus.com"> + <TT>libstdc++@sourceware.cygnus.com</TT></A>. + </P> + <P>If you have a question that you think should be included here, + or if you have a question <EM>about</EM> a question/answer here, + contact <A HREF="mailto:pme@sourceware.cygnus.com">Phil Edwards</A> + or <A HREF="mailto:gdr@egcs.cygnus.com">Gabriel Dos Reis</A>. + </P> + +<HR> + +<H1><A NAME="2_0">2.0 Installation</A></H1> + <H2><A NAME="2_1">2.1 How do I install libstdc++-v3?</A></H2> + <P>Complete instructions are not given here (this is a FAQ, not + an installation document), but the tools required are few: + <UL> + <LI> A release of libstdc++. + <LI> A recent release of GCC (version 2.95 works). Note + that building GCC is much easier and more automated + than building the GCC 2.[78] series was. + <LI> If you plan on hacking around with the makefiles, you + will need the tools <A +HREF="http://sourceware.cygnus.com/autoconf/">autoconf</A>and <A +HREF="http://sourceware.cygnus.com/automake/">automake</A>. + <LI> GNU Make is the only make that supports these makefiles. + </UL> + </P> + <P>The file <A HREF="../documentation.html">documentation.html</A> + provides a good overview of the steps necessary to build, install, + and use the library. Instructions for configuring the library + with new flags such as --enable-threads are there also. + </P> + <P>The top-level install.html and + <A HREF="../17_intro/RELEASE-NOTES">RELEASE-NOTES</A> files contain + the exact build and installation instructions. You may wish to + browse those files over CVSweb ahead of time to get a feel for + what's required. RELEASE-NOTES is located in the + ".../docs/17_intro/" directory of the distribution. + </P> + +<HR> + <H2><A NAME="2_2">2.2 Is this a drop-in replacement for the + libstdc++ that's shipped with g++?</A></H2> + <P>Yes, as of 2.90.8, it is intended as such.</P> + <P>The installation instructions cover this in more detail, but + replacing the older library requires rebuilding some of the + code that comes with g++. If you do not want to do that, + then you'll be missing out on a lot of functionality, but it + can still be done. + </P> + <P>In that case, you can use the same procedure that used to be + required: + <OL> + <LI> Build GCC as usual. + <LI> Build libstdc++-v3 as described in the installation + document, under the section "without GCC + sources." Be aware that you will lose the std:: + namespace encapsulation. + <LI> Build your code using -I and -L options so that GCC + finds the libstdc++-v3 headers and library before the + older headers in the GCC include tree. + </OL> + </P> + <P>If you configured libstdc++-v3 to install under a directory + called <B>/lib3</B>, for example, the command line would look + something like + <!-- Careful, the leading spaces in PRE show up directly. --> + <PRE> + g++ -Wall -I/lib3/include/g++-v3 -L/lib3/lib foo.cc -o foo + </PRE> + More information (such as using SGI or GNU extensions, and + setting the runtime library path) can be found in the RELEASE-NOTES. + </P> + +<HR> + <H2><A NAME="2_3">2.3 What is this CVS thing that you + keep mentioning?</A></H2> + <P>The <EM>Concurrent Versions System</EM> is one of several + revision control packages. It was selected for GNU projects + because it's free and very high quality. The <A + HREF="http://www.gnu.org/software/cvs/cvs.html">CVS entry in + the GNU software catalogue</A> has a better description as + well as a <A HREF="http://www.cyclic.com/">link to the makers + of CVS</A>. + </P> + <P>The "anonymous client checkout" feature of CVS is + similar to anonymous FTP in that it allows anyone to retrieve + the latest libstdc++ sources. + </P> + <P>After the first of April, American users will have a + "/pharmacy" command-line option... + <!-- wonder how long that'll live --> + </P> + +<HR> + <H2><A NAME="2_4">2.4 How do I know if it works?</A></H2> + <P>libstdc++-v3 comes with its own testsuite. You do not need + to actually install the library ("<TT>gmake + install</TT>") to run the testsuite. + </P> + <P>To run the testsuite on the library after building it, use + "gmake check" while in your build directory. To run + the testsuite on the library after building and installing it, + use "gmake check-install" instead. + </P> + <P>The testsuite subdirectory in your build directory will then + contain three files of the form YYYYMMDD-mkcheck*.txt. One of + them (-mkcheck.txt itself) contains the results of the tests; + this can be mailed to the list. The other files (-mkchecklog.txt + and -mkcheckfiles.txt) contain messages from the compiler while + building the test programs, and a list of the tests to be run, + respectively. + </P> + <P>If you are using the libgcc.a-rebuilding method to enable std:: + you might find that the testsuite starts dying with nasty linker + errors. This is symptomatic of the rebuilt libgcc.a not being + installed; the previous one is still in use. + </P> + <P>If you find bugs in the testsuite programs themselves, or if + you think of a new test program that should be added to the + suite, <B>please</B> write up your idea and send it to the list! + </P> + +<HR> +<H1><A NAME="3_0">3.0 Platform-Specific Issues</A></H1> + <H2><A NAME="3_1">3.1 Can libstdc++-v3 be used with <my + favorite compiler>?</A></H2> + <P>Probably not. Yet.</P> + <P>Because GCC advances so rapidly, development and testing of + libstdc++ is being done almost entirely under that compiler. + If you are curious about whether other, lesser compilers + (*grin*) support libstdc++, you are more than welcome to try. + Configuring and building the library (see above) will still + require certain tools, however. Also keep in mind that + <EM>building</EM> libstdc++ does not imply that your compiler + will be able to <EM>use</EM> all of the features found in the + C++ Standard Library. + </P> + <P>Since the goal of ISO Standardization is for all C++ + implementations to be able to share code, the final libstdc++ + should, in theory, be useable under any ISO-compliant + compiler. It will still be targeted and optimized for + GCC/g++, however. + </P> + +<HR> + <H2><A NAME="3_2">3.2 Building under Cygwin hangs/explodes!?</A></H2> + <P>Sometimes, yes. You're probably in the middle of generating + the <TT>numeric_limits</TT> specializations when it hangs, + right? Thought so... + </P> + <P>The <TT><limits></TT> header and its associated library + code are platform-specific. These files get generated from + scratch during installation, and it is this generator that is + hanging. More specifically, the only sure way to determine + what the <TT>numeric_limits<T>::traps</TT> boolean + should be is to actually divide by zero and see if it is + trapped or not. + </P> + <P>Under NT, this will occasionally just hang. On those + occasions when the test does not hang, the zero-division is + in fact trapped. That doesn't prevent hanging elsewhere. + </P> + <P>You have two options. + You can wait until the signal-handling in Cygwin is reworked + and released; this is planned to take "a few weeks" + and will result in a fix sometime in late December or early January. + Or you can get a prebuilt set of bits/std_limits.h and + src/limitsMEMBERS.cc files from Mumit Khan's + <A HREF="http://www.xraylith.wisc.edu/~khan/software/gnu-win32/libstdc++-v3.html">Cygwin-related + website</A>. + </P> + +<HR> +<H1><A NAME="4_0">4.0 Known Bugs and Non-Bugs</A></H1> + <EM>Note that this section can get rapdily outdated -- such is the + nature of an open-source project. For the latest information, join + the mailing list or look through recent archives. The RELEASE- + NOTES and BUGS files are generally kept up-to-date.</EM> + + <H2><A NAME="4_1">4.1 What works already?</A></H2> + <P>This is a verbatim clip from the "Status" section + of the RELEASE-NOTES for the latest snapshot. + </P> + +<!-- Yeah, I meant that "verbatim clip" thing literally... :-) --> + +<pre> +New: +--- +- MT safe string. Supported CPUs are alpha, powerpc, x86, sparc32 and sparc64. +- Configure support for --enable-threads=posix, as well as initial IO + locking implementation. +- Support for native building on Solaris 2.5.1, Solaris 2.6, Solaris + 2.7, cygwin, [alpha, powerpc, x86]-linux, and preliminary support for + Irix and Aix4.2, Aix 4.3 hosts. +- --enable-namespaces is on by default. +- Configure and Makefile support for "drop-in" replacement to + libstdc++-v2 completed. It is now possible to bootstrap g++, and + have g++ find libstdc++-v3 headers and libraries by default. +- Synched with CVS egcs libio. +- Cygwin native compiling supported. +- Cross compiling and embedded targets (newlib) with multilibs support added. +- SGI's strstream implementation has been added. +- Copyright on all sources assigned to the FSF. +- Configure, build and install documentation has been added. +- Support to enable long long has been added. +- More valarray improvements. +- Extractors and inserters for std::complex have been added. +- Extractors and inserters for void* have been fixed. +- autoconf macros are now in _GLIBCPP_ namespace. +- group checking for num_get implemented. +- Many, many bug fixes. +</pre> + + +<HR> + <H2><A NAME="4_2">4.2 Bugs in gcc/g++ (not libstdc++-v3)</A></H2> + <P>This is by no means meant to be complete nor exhaustive, but + mentions some problems that users may encounter when building + or using libstdc++. If you are experiencing one of these + problems, you can find more information on the libstdc++ and + the GCC mailing lists. + </P> + <UL> + <LI>When using associative containers (like <TT>map</TT>), and + compiling with <TT>-O3</TT> (or <TT>-finline-functions</TT>) + and <TT>-Winline</TT>, I get a zillion errors like: + <!-- Careful, the leading spaces in PRE show up directly. --> + <PRE> + .../include/g++/stl_tree.h: In function `int __black_count(struct __rb_tree_node_base *, struct __rb_tree_node_base *)': + .../include/g++/stl_tree.h:1045: warning: can't inline call to `int __black_count(struct __rb_tree_node_base *, struct __rb_tree_node_base *)' + .../include/g++/stl_tree.h:1053: warning: called from here + </PRE> + <P>This has been discussed a number of times; the problem + is that __black_count is marked inline but is also a + recursive function. As of 12 July 1999, it has been + rewritten into an optimized non-recursive form, so + fresh checkouts/releases should no longer see this warning. + (The compiler can usually figure out how to make that + transformation on its own.) + </P> + + <LI>The reason that EGCS 1.1.2 cannot be used to build the + library is that lookups do not work properly, and so the + compiler will ICE when building the locale-related source + files. This has been fixed in GCC 2.95. + </UL> + +<HR> + <H2><A NAME="4_3">4.3 Bugs in the C++ language/lib specification</A></H2> + <P>Yes, unfortunately, there are some. In a <A +HREF="/ml/libstdc++/1998/msg00006.html">message +to the list</A>, Nathan Myers announced that he has started a list of + problems in the ISO C++ Standard itself, especially with + regard to the chapters that concern the library. The list + itself is <A + HREF="http://www.cantrip.org/draft-bugs.txt">posted on his + website</A>. Developers who are having problems interpreting + the Standard may wish to consult his notes. + </P> + <P>For those people who are not part of the ISO Library Group + (i.e., nearly all of us needing to read this page in the first + place :-), a public list of the library defects is occasionally + published <A HREF="http://anubis.dkuug.dk/jtc1/sc22/wg21/">here</A>. + </P> + +<HR> + <H2><A NAME="4_4">4.4 Things in libstdc++ that look like bugs</A></H2> + <P>There are things which are not bugs in the compiler (4.2) nor + the language specification (4.3), but aren't really bugs in + libstdc++, either. Really! + </P> + <P>The biggest of these is the quadzillions of warnings about the + library headers emitted when <TT>-Weffc++</TT> is used. Making + libstdc++ "-Weffc++-clean" is not a goal of the project, + for a few reasons. Mainly, that option tries to enforce + object-oriented programming, while the Standard Library isn't + necessarily trying to be OO. There are multiple solutions + under discussion. + </P> + +<HR> + <H2><A NAME="4_5">4.5 Aw, that's easy to fix!</A></H2> + <P>If you have found a bug in the library and you think you have + a working fix, then send it in! The main GCC site has a page + on <A HREF="http://egcs.cygnus.com/contribute.html">submitting + patches</A> that covers the procedure, but for libstdc++ you + should of course send the patch to our mailing list, not the + GCC mailing list. The libstdc++ + <A HREF="../17_intro/contribute.html">contributors' page</A> + also talks about how to submit patches. + </P> + <P>In addition to the description, the patch, and the ChangeLog + entry, it is a Good Thing if you can additionally create a small + test program to test for the presence of the bug that your + patch fixes. Bugs have a way of being reintroduced; if an old + bug creeps back in, it will be caught immediately by the + <A HREF="#2_4">testsuite</A> -- but only if such a test exists. + </P> + +<HR> +<H1><A NAME="5_0">5.0 Miscellaneous</A></H1> + <H2><A NAME="5_1">5.1 string::iterator is not char*; + vector<T>::iterator is not T*</A></H2> + <P>If you have code that depends on container<T> iterators + being implemented as pointer-to-T, your code is broken. + </P> + <P>While there are arguments for iterators to be implemented in + that manner, A) they aren't very good ones in the long term, + and B) they were never guaranteed by the Standard anyway. The + type-safety achieved by making iterators a real class rather + than a typedef for <TT>T*</TT> outweighs nearly all opposing + arguments. + </P> + +<HR> + <H2><A NAME="5_2">5.2 What's next after libstdc++-v3?</A></H2> + <P>Hopefully, not much. The goal of libstdc++-v3 is to produce + a fully-compliant, fully-portable Standard Library. After that, + we're mostly done: there won't <EM>be</EM> any more compliance + work to do. + </P> + <P>The ISO Committee will meet periodically to review Defect Reports + in the C++ Standard. Undoubtably some of these will result in + changes to the Standard, which will be reflected in patches to + libstdc++. Some of that is already happening, see 4.2. + </P> + <P>The current libstdc++ contains extensions to the Library which + must be explicitly requested by client code (for example, the + hash tables from SGI). Other extensions may be added to + libstdc++-v3 if they seem to be "standard" enough. + (For example, the "long long" type from C99.) + Bugfixes and rewrites (to improve or fix thread safety, for + instance) will of course be a continuing task. + </P> + <P><A +HREF="http://sourceware.cygnus.com/ml/libstdc++/1999/msg00080.html">This + question</A> about the next libstdc++ prompted some brief but + interesting <A +HREF="http://sourceware.cygnus.com/ml/libstdc++/1999/msg00084.html">speculation</A>. + </P> + +<HR> + <H2><A NAME="5_3">5.3 What about the STL from SGI?</A></H2> + <P>The <A HREF="http://www.sgi.com/Technology/STL/">STL from SGI</A> + is merged into libstdc++-v3 with changes as necessary. + Currently release 3.2 is being used. Changes in the STL + usually produce some weird bugs and lots of changes in the + rest of the libstd++ source as we scramble to keep up. :-) + </P> + <P>In particular, <TT>string</TT> is not from SGI and makes no + use of their "rope" class (which is included as an + optional extension), nor is <TT>valarray</TT> and some others. + Classes like <TT>vector<></TT> are, however. + </P> + <P>The FAQ for SGI's STL (one jump off of their main page) is + recommended reading. + </P> + +<HR> + <H2><A NAME="5_4">5.4 Extensions and Backward Compatibility</A></H2> + <P>Although you can specify <TT>-I</TT> options to make the + preprocessor search the g++-v3/ext and /backward directories, + it is better to refer to files there by their path, as in: + <!-- Careful, the leading spaces in PRE show up directly. --> + <PRE> + #include <ext/hash_map> + </PRE> + </P> + +<HR> + <H2><A NAME="5_5">5.5 Compiling with "-fnew-abi"</A></H2> + <P>The library mostly works if you compile it (and programs you + link with it) using "-fnew-abi -fno-honor-std" on a + vanilla GCC compiler. However, some features, such as RTTI + and error handlers, might not link properly with a vanilla + libgcc built in GCC under the old ABI. If you rebuild libgcc + using the "-f" flags above, you can get both complete + language support and full benefits of -fnew-abi -- short + mangled symbol names, far more efficient exception handling, + and empty base optimization, to name a few. (Note that the + new ABI may change from one GCC snapshot to the next, so you + would have to rebuild all your libraries each time you get a + new compiler snapshot.) + </P> + <P>Towards the end of July 1999, this subject was brought up again + on the mailing list under a different name. The related + <A HREF="/ml/libstdc++/1999-q3/msg00066.html">thread</A> + (by the name HOWTO-honor-std) is very instructive. More info + is at the end of RELEASE-NOTES. + </P> + <P>This functionality is now automated and turned on by default. + </P> + +<HR> + <H2><A NAME="5_6">5.6 Is libstdc++-v3 thread-safe?</A></H2> + <P>Quick answer: no, as of 2.90.8 (ninth snapshot), the + library is not appropriate for multithreaded access. The + string class is MT-safe. + </P> + <P>This is assuming that your idea of "multithreaded" + is the same as ours... The general question of multithreading + and libstdc++-v3 is addressed in the chapter-specific advice for +<A HREF="http://sourceware.cygnus.com/libstdc++/17_intro/howto.html#3">Library + Introduction</A>. Threadsafe containers are covered in + more detail in +<A HREF="http://sourceware.cygnus.com/libstdc++/23_containers/howto.html">the + Received Wisdom section on containers</A>. + <!-- I have successfully evaded the topic; my work here is + done- no, wait, I have to write those other sections... --> + </P> + +<HR> + <H2><A NAME="5_7">5.7 How do I get a copy of the ISO C++ Standard?</A></H2> + <P>Copies of the full ISO 14882 standard are available on line + via the ISO mirror site for committee members. Non-members, + or those who have not paid for the privilege of sitting on + the committee and sustained their two-meeting commitment for + voting rights, may get a copy of the standard from their + respective national standards organization. In the USA, + this national standards organization is ANSI and their + website is right <A HREF="http://www.ansi.org">here</A>. + (And if you've already registered with them, clicking this + link will take you to directly to the place where you can +<A HREF="http://webstore.ansi.org/ansidocstore/product.asp?sku=ISO%2FIEC+14882%2D1998">buy + the standard on-line</A>. + </P> + <P>Who is your country's member body? Visit the + <A HREF="http://www.iso.ch/">ISO homepage</A> and find out! + </P> + +<!-- ####################################################### --> + +<HR> +<P CLASS="fineprint"><EM> +Comments and suggestions are welcome, and may be sent to +<A HREF="mailto:pme@sourceware.cygnus.com">Phil Edwards</A> or +<A HREF="mailto:gdr@egcs.cygnus.com">Gabriel Dos Reis</A>. +<BR> $Id: index.html,v 1.21 2000/03/26 03:44:35 pme Exp $ +</EM></P> + + +</BODY> +</HTML> |