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BOOST_DEBUG like macros: current state overview
by Pavel Vozenilek 13 Jun '04

13 Jun '04

Some time ago I suggested to add support for BOOST_DEBUG and BOOST_NDEBUG macros into guidelines. I searched how individual libraries (1.31) handle debug support: ------------------------------------- * lexical_cast - uses assert() * dynamic_bitset - uses assert() * filesystem - uses assert() * graph - uses assert() * interval - uses assert() * thread - uses assert() * tokenizer - uses assert() * random - uses assert() * lambda - uses assert() * multi_array - uses assert() * signals - uses assert() * format - uses BOOST_ASSERT() * function - uses BOOST_ASSERT() * variant - uses BOOST_ASSERT * optional - uses BOOST_ASSERT * smart_ptr - uses BOOST_ASSERT and macro with somewhat misleading name BOOST_SP_ENABLE_DEBUG_HOOKS * concept_check - uses NDEBUG directly * ublas - uses its own macro BOOST_UBLAS_CHECK depending on NDEBUG. Documented * python - uses its own macro BOOST_PYTHON_INDEXING_CHECK_INVARIANT depending on NDEBUG and also NDEBUG directly. Not documented * regex - uses assert() based on BOOST_REGEX_DEBUG and jm_assert (macro too). Uses also BOOST_REGEX_DEBUG directly. No dependence on NDEBUG. Not documented. * spirit - uses macro BOOST_SPIRIT_ASSERT depending on assert() as well as handful of other library specific debug macros. Well documented. Circular Buffer, Multi Index Container and likely Serialization contain (documented) extensive support for debug mode with their specifi macros and different level modes. ------------------------------------- Documentation usually doesn't mention if/how debug support is implemented. Maybe common macros would make life of Boost user easier. /Pavel

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config and .cxx extensions
by David Abrahams 13 Jun '04

13 Jun '04

Is there a good reason that the config library needs to use a "creative" choice of file extensions rather than the boost standard of ".*pp"? -- Dave Abrahams Boost Consulting http://www.boost-consulting.com

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Can anyone help with this one?
by Thomas Don Aratari 12 Jun '04

12 Jun '04

Hello, I'm trying to upgrade my boost to 1_31 but I keep getting the following tokenizer error. I am using Forte 8.0 (CC: Sun C++ 5.5 Patch 113817-03 2003/10/14). Here is the code snip: (passing in sString to be tokenized) typedef boost::tokenizer<boost::char_separator<char> > tokenizer; boost::char_separator<char> seperator(sDroppedDelimiters, sKeptDelimiters, boost::keep_empty_tokens); tokenizer tokens( sString, seperator ); for (tokenizer::iterator tok_iter = tokens.begin(); tok_iter != tokens.end(); ++tok_iter) vInVector.push_back( *tok_iter ); "/home/dev/cm/THIRD_PARTY/boost/include/boost/iterator/iterator_facade.hpp", line 623: Error: Could not find a match for boost::iterator_core_access::equal<boost::iterator_core_access::Facade1, boost::iterator_core_access::Facade2>(const boost::token_iterator<boost::char_separator<char, std::char_traits<char>>, const char*, std::string>, const boost::token_iterator<boost::char_separator<char, std::char_traits<char>>, const char*, std::string>, boost::is_convertible<boost::token_iterator<boost::char_separator<char, std::char_traits<char>>, const char*, std::string>, boost::token_iterator<boost::char_separator<char, std::char_traits<char>>, const char*, std::string>>). "MDSStringHelpers.cxx", line 183: Where: While instantiating "boost::operator!=<boost::token_iterator<boost::char_separator<char, std::char_traits<char>>, const char*, std::string>, std::string, boost::forward_traversal_tag, const std::string &, int, boost::token_iterator<boost::char_separator<char, std::char_traits<char>>, const char*, std::string>, std::string, boost::forward_traversal_tag, const std::string &, int>(const boost::iterator_facade<boost::token_iterator<boost::char_separator<char, std::char_traits<char>>, const char*, std::string>, std::string, boost::forward_traversal_tag, const std::string &, int>&, const boost::iterator_facade<boost::token_iterator<boost::char_separator<char, std::char_traits<char>>, const char*, std::string>, std::string, boost::forward_traversal_tag, const std::string &, int>&)". "MDSStringHelpers.cxx", line 183: Where: Instantiated from non-template code. Any ideas how to fix or has anyone else seen this? Thanks Tom

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Re: New C++ Zine (Print version?)
by Chuck Allison 12 Jun '04

12 Jun '04

Hello Dave, Saturday, June 12, 2004, 11:01:35 AM, you wrote: brlbo> "Chuck Allison" <chuck(a)freshsources.com> wrote in message brlbo> news:15110019883.20040611130022@freshsources.com... >> [...] >> David Abrahams suggested I could send you an announcement >> on this list. For some time now (since last October, actually) a >> group of C++ luminaries have been discussing the virtues and >> possibilities of a peer-reviewed source for the C++ community. brlbo> Is it likely there will be a print edition in the future? If so, is there a brlbo> timetable for it's appearance? brlbo> Dave We have discussed having a periodic (annual?) print anthology (a la C++ Gems), but of course, we haven't even launched yet, so we're getting ahead of ourselves. With sufficient success/resources, the answer is "yes". -- Best regards, Chuck

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Re: Announcing a New C++ Zine
by Chuck Allison 12 Jun '04

12 Jun '04

Hello Alexander, I'm sorry, but that page is just a sample page. Bjarne's article is not an official posting. We haven't launched yet. If you want to discuss the content of Bjarne's comments, you can email him directly, but it has nothing to do with The C++ Source. Sorry if I didn't make it clear that that page was just a sample. I meant to. Saturday, June 12, 2004, 11:01:35 AM, you wrote: brlbo> Chuck Allison wrote: brlbo> [...] >> viewing at http://www.artima.com/cppsource. The idea is to have brlbo> Quoting from http://www.artima.com/intv/elegance.html. Few comments brlbo> follow. brlbo> <quote author=Bjarne Stroustrup> brlbo> I don't put in specific features for concurrency, because you can put brlbo> them in a library. brlbo> </quote> brlbo> You can't do that without threaded memory model, to begin with. brlbo> <quote> brlbo> C was designed with the principle that you should be able to write brlbo> its standard library in the language itself. That same principle brlbo> guided the design of C++. brlbo> </quote> brlbo> Show me the the standard C++ impl of atomic<> for a rather simple brlbo> thing like brlbo> class swap_based_mutex_for_windows { // noncopyable brlbo> atomic<int> m_lock_status; // 0: free, 1/-1: locked/contention brlbo> auto_reset_event m_retry_event; // "slow" bin sema/gate brlbo> public: brlbo> // ctor/dtor [w/o lazy event init] brlbo> void lock() throw() { brlbo> if (m_lock_status.swap(1, msync::acq)) brlbo> while (m_lock_status.swap(-1, msync::acq)) brlbo> m_retry_event.wait(); brlbo> } brlbo> bool trylock() throw() { brlbo> return !m_lock_status.swap(1, msync::acq) ? brlbo> true : !m_lock_status.swap(-1, msync::acq); brlbo> } brlbo> bool timedlock(absolute_timeout const & timeout) throw() { brlbo> if (m_lock_status.swap(1, msync::acq)) { brlbo> while (m_lock_status.swap(-1, msync::acq)) brlbo> if (!m_retry_event.timedwait(timeout)) brlbo> return false; brlbo> } brlbo> return true; brlbo> } brlbo> void unlock() throw() { brlbo> if (m_lock_status.swap(0, msync::rel) < 0) brlbo> m_retry_event.set(); brlbo> } brlbo> }; brlbo> regards, brlbo> alexander. -- Best regards, Chuck

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Re: static sized strings (struct hack)
by Bill Seymour 12 Jun '04

12 Jun '04

Rob Stewart: > > From: John Nagle <nagle(a)animats.com> > > > From: "Reece Dunn" <msclrhd(a)hotmail.com> > > > > >> class fs_base > > >> { > > >> size_t len; > > >> szie_t capacity; // needed for buffer-safe operations > > >> CharT str[ 1 ]; > > >> // string manipulation functions > > >> > > >> fs_base( size_t c ): capacity( c ){} > > >> }; > > >> > > >> template< size_t n > > > >> class fixed_string: public fs_base > > >> { > > >> CharT data[ n ]; > > >> fixed_string(): fs_base( n ){} > > >> }; > > > > Are you assuming that "data[n]" physically follows > > "str[1]" in memory, and that "data[n]" can be addressed > > by subscripting "str[1]" out of range? ... > > Oh, right. It was C99 that blessed the struct hack. Oh well. > Well, yes; but the struct hack is not what the code above tries to do. What C99 says is that you can malloc sizeof(fs_base) plus some extra, then address str[2] to str[whatever up to malloc'd size]. Even in C99 (and even if C understood the C++-specific stuff in the above), there is no relationship between fs_base::str and fixed_string::data (except that they don't overlap). --Bill Seymour

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More Math Functions
by Paul A Bristow 12 Jun '04

12 Jun '04

|-----Original Message----- |From: boost-bounces(a)lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf |Of Tom Brinkman |Sent: 03 June 2004 00:54 |To: boost(a)lists.boost.org |Subject: [boost] Boost Mathematicians |What is the current status of all Boost mathmatical, |statistical and econometric libraries currently in |development? |The collection of boost math libraries that are |currently included in the library are world-class and |provide a wonderful foundation to build-upon. |However, many areas of advanced statistical and |mathmatical inference are not currently being \addressed by any of the boost libraries. I have been off-line for some time, but have now caught up with this discussion a bit. Strongly support your views and need these things yesterday ;-) Apart from messing about with Microsoft Windows problems, I have been preparing a formal proposal for C and C++ Standard Library TR-2 of a list of Math 'Special' Functions (additional to those from Walter Brown which have been accepted into TR-1). This list will include all the usual statistical suspects - including Student's t, Chi sqr, and F, so that at last it will be possible easily write C++ to provide the probability that means of two series of measurements differ. (The key function is the incomplete beta; it is also the most difficult to write well). Fortunately I have persuaded Stephen Moshier, author of the Cephes function library (in C) to make this available under Boost licence terms. So implementors will have no excuse to hide behind (the reason why these functions were omitted by Walter Brown). It should be possible to produce a working (and I believe rather good) implementation with little more than renaming the functions. This might be submitted for a Boost library. I hope to expose a revised draft to the rigours of Boost and C++.std newsgroup Real Soon Now. Paul Paul A. Bristow Prizet Farmhouse, Kendal UK LA8 8AB +44 1539 561830 07714 33 02 04 pbristow(a)hetp.u-net.com

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Paul Mensonides:
by Vesa Karvonen 12 Jun '04

12 Jun '04

[boost] Re: Some remarks on PP docs Date: Fri, 11 Jun 2004 16:36:19 +0300 Mime-Version: 1.0 Content-Type: text/plain; format=flowed Paul Mensonides: >Chaos, as opposed to Order, intentionally encourages better >understanding of the actual language being used (which is not Chaos, but >the preprocessor) rather than trying to hide it as much as possible. I've discussed this with you earlier, but I'd still like to point out that the intention behind the design of Order has not been to "hide as much as possible" or to discourage "better understanding", but rather to *provide* a language that definitely *is* easy to understand and convenient to use. A person unfamiliar with Boost.PP should be able to learn to use something like Order and use it for productive, even non-trivial, work (which is usually C or C++ code generation) in significantly shorter period of time than it takes to learn how to do similar things with Boost.PP (or Chaos). I also noticed other, IMO, misleading comments on Order [vs Chaos], but I don't have the time to comment on those at the moment. -Vesa Karvonen _________________________________________________________________ The new MSN 8: advanced junk mail protection and 2 months FREE* http://join.msn.com/?page=features/junkmail

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Re: Some remarks on PP docs
by Vesa Karvonen 12 Jun '04

12 Jun '04

David Abrahams: >I'm writing an appendix on the PP lib for the MPL book today. I think >that'll demonstrate that it's possible to provide a reasonable gentle >and high-level introduction without exposing too many ugly details. That would be great! >- Fundamental PP Abstractions > - Macros > - Non function > - Function macros > - Tokens > - Sequences of tokens not including un-parenthesized commas Data structures are an important topic and their representation isn't fundamentally PP *library* specific. You might want to present the information on the representation of data structures (and simple macros like a projection operator for tuples and some sequences operations) here when you discuss fundamental PP abstractions. I would also probably discuss how to implement primitives like IF and WHILE using preprocessor macros at this point. The purpose being to show that the preprocessor is capable of significant computation. I would also emphasize that the purpose of explaining the techniques is not that people would roll their own versions, but simply to deepen their understanding of the preprocessor. >Well, if you really have a conforming C99 preprocessor, you could use >Paul M's Chaos, which I think is both easier to use and *way* more >efficient than the current Boost PP. >From what I know, Chaos is essentially an extended Boost.PP (meaning that Chaos is essentially a combinator library), with a single recursion backend (enabled by stricter requirements on preproprecessor conformance), which makes it more orthogonal. However, Chaos still shares many problems with Boost.PP, the main issues being that code will be highly verbose and very intricate. The verbosity and intricacy probably do not matter that much when one only performs simple repetition using the canned library macros. -Vesa Karvonen _________________________________________________________________ Protect your PC - get McAfee.com VirusScan Online http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963

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Some remarks on PP docs
by David Abrahams 12 Jun '04

12 Jun '04

techniques.html: It is usually okay to use a standard macro name like BOOST_PP_DEF for this kind of code because the macro is both defined and undefined in the immediate site of its use. I was really confused by the use of the word "standard". This would be clearer: It is usually okay to reuse a single generic macro name like BOOST_PP_DEF throughout your code because the macro is both defined and undefined very close to its point of use. Although I don't know why you'd want to advocate that over using a descriptive name. ------ A clearer divider between examples would be a *huge* help visually. An <hr> would be enough, for example. Example - Use BOOST_PP_EMPTY as an unused parameter in local macro instantiations. #define BOOST_PP_DEF(cv) /* ... */ \ template<class base> \ cv() typename implement_subscript_using_begin_subscript<base>::value_type& \ implement_subscript_using_begin_subscript<base>::operator[](index_type i) cv() { \ return base::begin()[i]; \ } \ /**/ ?? Where is BOOST_PP_EMPTY used in this example? I think I know what you mean, but really, you need to show it! How: BOOST_PP_EMPTY() expands to nothing and can be used as an unused parameter. Note: BOOST_PP_EMPTY with the () never gets expanded. This sounds self-contradictory. Just above you said it expands (to nothing)! The () is necessary to invoke a function-like macro. No duh; I think stating the obvious that way only adds confusion. Caveat: You cannot safely use concatenation while using BOOST_PP_EMPTY(). That's way too vague and general. I certainly can use concatenation and BOOST_PP_EMPTY "together", for many reasonable definitions of that word! I think you need to be more specific, or strike it. ------ The BOOST_PP_ENUM_PARAMS example could benefit greatly from a side-by-side format in a table showing the expansion on the right. In fact, that would help all the examples, but in particular if you're just getting acquainted with the library at this point you may not have any idea what some of those macros do. You're advocating that people use them here, but unless the reader has some idea of what they generate, it's lost on her. Showing not-even-correct details of BOOST_PP_REPEAT's implementation doesn't help here. I'd strike it. Furthermore, BOOST_PP_ENUM_PARAMS and its variations use BOOST_PP_REPEAT. BOOST_PP_COMMA_IF(I) expands to a comma if I != 0. BOOST_PP_INC(I) essentially expands to "I+1," and BOOST_PP_DEC(I) essentially expands to "I-1.". I'd strike that too. You haven't said a word about BOOST_PP_INC/DEC yet, so the reader is left wondering why you're giving their implementation details. ----- Example - Use BOOST_PP_REPEAT and a token look-up function to eliminate categorical repetition. Is this really better than iterating over a SEQ of categories in any way other than efficiency? ----- Example - Use BOOST_PP_REPEAT to avoid O(n*n) repetition. It's unclear to me how that example avoids O(n*n) repetition. It certainly seems to have that complexity, and that appears to be intrinsic to the code it generates. Maybe you mean Example - Use BOOST_PP_REPEAT for O(n*n) repetition. Or something? ----- BOOST_PP_IF enables convenient generation of lists using BOOST_PP_REPEAT. This statement, without an example, is too vague to be helpful. ----- Implementation details of BOOST_PP_IF don't help: How: BOOST_PP_IF is defined for the entire repeat range (psuedo code): #define BOOST_PP_IF(c, THEN, ELSE) BOOST_PP_IF ## c(THEN, ELSE) #define BOOST_PP_IF0(THEN, ELSE) ELSE #define BOOST_PP_IF1(THEN, ELSE) THEN #define BOOST_PP_IF1(THEN, ELSE) THEN ^ especially since they appear to be wrong. I think the point is that BOOST_PP_IF works on first arguments other than 0 or 1. If so, you should just say that it works on numeric arguments up to N (whatever N is). --------- Example: Use arithmetic, logical, and comparison operations when necessary. With no commentary, and no generated code, this example is really useless. I mean, of course you'd use arithmetic, logical, and comparison operations "when neccessary". -- Dave Abrahams Boost Consulting http://www.boost-consulting.com

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