- Boost-users - lists.preview.boost.org

mpl::if_ or mpl::apply_if?
by Markus Werle 27 Feb '03

27 Feb '03

Hi! I am trying to migrate some parts of my code from loki to boost::mpl. Q1: which is the best way to perform nested if-then-else? Assume given "values": bool B1, bool B2; class ff, class tf, class ft, class tt; I replaced ----------------------------------------------------------- typedef typename Loki::Select<B1, typename Loki::Select<B2, tt, tf>::Result, typename Loki::Select<B2, ft, ff>::Result >::Result type; ----------------------------------------------------------- with typedef typename apply_if < bool_c<B1>, apply_if < bool_c<B2>, identity<tt>, identity<tf> >, apply_if < bool_c<B2>, identity<ft>, identity<ff> > >::type type; Q2: Is apply_if always to be preferred over if_? Q3: (OT) Is there a mpl-equivalent to run-time case? best regards, Markus

4 10

Re: [Boost-Users] Re: are namespaces of boost libs required to be lowercase?
by Beman Dawes 27 Feb '03

27 Feb '03

At 11:37 AM 2/27/2003, William E. Kempf wrote: > >Markus Werle said: >> A hard burden You lay on developers. > >It's not a burden. > >> So maybe the code has to be piped through a >> code de-beautifier when it comes to a boostification. > >That's a bit harsh. If *you* don't care for the style, you're welcome to >that opinion, but voicing it in this manner isn't going to help anyone to >agree with you. > >> IMHO (UsingThisConventionHere == CommonPracticeElsewhere) > >It's not common practice everywhere (I know of as many places that follow >the C++ standard naming conventions as those that follow what I'll call >"Java" naming conventions). But the important thing is that the whole >point of Boost is to be a test bed and development area for libraries that >*might* be considered for inclusion in the standard. As such, we have to >follow the standard naming conventions. Exactly. And it isn't just a theoretical "*might* be considered for inclusion in the standard". A bunch of the Boost libraries *are* under consideration by the Standards Committee right now, and more will be in the future. For a library to be considered seriously for standardization, it helps a great deal if every aspect, including names, has been subject to prior use. That flushes out issues that otherwise would be hidden. So there is little chance Boost will change naming conventions. I suppose we might accept a library which used a different set of conventions if there was some special rationale. But I can't imagine what that rationale would be. It certainly would not be just that a developer prefers another convention. --Beman

1 0

boost 1.29.0: shared_from_this with const argument
by Michael Brinkmann 27 Feb '03

27 Feb '03

Hi, In my opinion, the call "shared_from_this(T* p)" in the file "boost/shared_ptr.hpp" is meant to be "shared_from_this(T const* p)" Am I right? kind regards Michael

2 1

UBLAS: advice on argument types please
by speedsnaii <speedsnaii＠yahoo.de> 27 Feb '03

27 Feb '03

I am trying to find a good choice for argument types to a function. (Please be patient, I am a poor user of C++ who has not yet understood all this expression template magic.) I'd like to have a function: void foo( whattype arg) { } matrix<double> m(3,3); vector<double> v(6); and call it like: foo(m.column(0)); foo(m.row(0)); foo(v); Is this feasible? Should I use iterators for whattype? (how do I access size information then?) Am I trying to misuse the ublas when asking such a question? (Which container should I use in this case?) In the hope anyone can shade some light on it. Thank you, Roland

2 11

Building with Sun Workshop 6
by markrday <markrday＠yahoo.com> 27 Feb '03

27 Feb '03

I've searched the archives, and haven't found a report of successfully building Boost using the Sun Workshop compiler, though some messages imply that people are using at least some of the libraries with Workshop. Although I realize we could build the libraries with gcc, we have quite a few projects set up in the workshop environment, and I'd like to have the option to use Boost libraries with them. Obviously nobody has built an appropriate toolset. In my naive attempts to create a toolset definiton, and in trying to create a static library from components like Date-Time library, I get error messages like: add_const.hpp, line 34: Warning: Too few arguments in macro BOOST_PP_CHECK_2. There are also errors involving BOOST_PP_LIST_FOR_EACH_I_M (among others). Can anyone offer me hints on how to get started in resolving these? Ultimately I'd like to have the whole suite compiled, but for the time being I'd be happy just using Date-Time. I'm willing to build a toolset file for this compiler, but I don't seem to have the expertise. If there's anyone that is able to provide guidance, I can put some time into this, and submit a toolset definition file so others can use Boost with this compiler.

3 3

Problem with time_period
by Alejandro Escalante Medina <alejandro_escalante_medina＠yahoo.com.mx> 27 Feb '03

27 Feb '03

The following simple code doesn't compile: ---------------------------------------------- #define DATE_TIME_INLINE #include <boost/date_time/gregorian/gregorian.hpp> #include <boost/date_time/posix_time/posix_time.hpp> using namespace boost; using namespace boost::posix_time; using namespace boost::gregorian; ... time_period p(ptime(date(2003, 03, 25)), ptime(date(2003, 04, 25))); date_duration duration(days(1)); p.shift(duration); ---------------------------------------------------- the compiler (VC++ 7.0) gives the following: error C2664: 'boost::date_time::period<class boost::posix_time::ptime,class boost::posix_time::time_duration>::shift' : cannot convert parameter 1 from 'boost::gregorian::date_duration' to 'const boost::posix_time::time_duration &' Reason: cannot convert from 'boost::gregorian::date_duration' to 'const boost::posix_time::time_duration' No constructor could take the source type, or constructor overload resolution was ambiguous I think this should work out of the box, since I've been doing lots of other things with date_time and they work fine. Any ideas? Thanks in advance, Alex

1 0

uBLAS - Matrix Inversion
by Thomas Reisinger 25 Feb '03

25 Feb '03

Dear Newsgroup, I'm new in the field of numeric computing and I would like to learn more about it. To solve my problem I need to invert a matix and use the intermediate result as the input for following calculations. I browsed the uBLAS library and played a little bit with it but I didn't find a routine for matrix inversion. Is there any possibility to preform it in a single step? Is this package the wrong tool for doing this and I should use LAPACK++ or similar stuff? Thanks in advance, Thomas -- Thomas Reisinger Braunschweig Germany mailto:t.reisinger@tu-bs.de

4 3

date_time problems
by Eric Crampton 25 Feb '03

25 Feb '03

I'm trying to test the date_time functionality of boost and am having some difficulties. I would like to simply get the current local time into a ptime and write it out as an ISO-8601 string. Using Boost 1.29 and g++ 3.2, when I compile the following code I get a number of *linker* errors. Code: #include <boost/date_time/posix_time/posix_time_types.hpp> #include <boost/date_time/posix_time/time_formatters.hpp> int main() { boost::posix_time::ptime pt = boost::posix_time::second_clock::local_time(); std::cout << boost::posix_time::to_iso_extended_string(pt) << std::endl; } That code seems pretty straightforward to me. The linker errors look like the following: test.cpp:7: undefined reference to `boost::date_time::gregorian_calendar_base<boost::date_time::year_month_day_base<boost::gregorian::greg_year, boost::gregorian::greg_month, boost::gregorian::greg_day>, unsigned long>::day_number(boost::date_time::year_month_day_base<boost::gregorian::greg_year, boost::gregorian::greg_month, boost::gregorian::greg_day> const&)' test.cpp:6: undefined reference to `boost::date_time::gregorian_calendar_base<boost::date_time::year_month_day_base<boost::gregorian::greg_year, boost::gregorian::greg_month, boost::gregorian::greg_day>, unsigned long>::from_day_number(unsigned long)' (snipped...) Best as I can tell (cd $BOOST_ROOT/boost/date_time && find . -name '*.cpp' -print), there are no .cpp files to be compiled... Anyone know what's up? --Eric _________________________________________________________________ Protect your PC - get McAfee.com VirusScan Online http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963

4 3

Please help! Problem with histogram.cpp needed for project.
by agiatojon <JonAgiato＠nyc.rr.com> 25 Feb '03

25 Feb '03

Hello all, I have been unable to successfully compile histogram.cpp in the random library folder, version 1_29_0, using Visual Studio.NET. I obtain the following errors: c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(49): warning C4267: 'argument' : conversion from 'size_t' to 'std::streamsize', possible loss of data c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(101): error C2065: 'gen' : undeclared identifier c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type It appears to me that all of these messages will go away when the second one, c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base', is corrected. Any assistance is greatly appreciated! Thank you. Jon Agiato JonAgiato(a)nyc.rr.com

1 0

Is implicit casting with boost::any possible?
by Matthew Dempsky 25 Feb '03

25 Feb '03

I'm curious if there's any way to get code like the following to work: boost::any a = char(10); int i = boost::any_cast<int>(a); More specifically, what I mean is, I'd like to be able to place a value of type T1 in 'a' and then retrieve it as type T2 which it can be implicitly cast to. Is this possible without the part that extracts the value from 'a' adding a lot of extra code to test all possibilities? What I would like to do is fill a map<string, any> with function pointers/objects/etc. and pass it to a function which casts the any values to slot types to connect to different signals whose type is determined at runtime. Basically something like this (but with MySig an unknown type until runtime). int func(char c, int i = 10); boost::any a = &func; typedef boost::signal<void (char)> MySig; MySig sig; sig.connect(boost::any_cast<MySig::slot_type>(a)); sig('j'); -jivera

2 1

C++ object from PyObject pointer
by mghiggins <mghiggins＠yahoo.com> 24 Feb '03

24 Feb '03

Excuse my newbiness if this question is too dumb... :) I've built a python extension from a C++ class using boost - it all seems to work fine. However, now another C++ function is receiving a pointer to a PyObject that represents an instance of this "boosted" python class. How do I pick off a pointer to the underlying C++ object from the PyObject pointer?

2 1

Re: [Boost-Users] lexical_cast bug.
by Terje Slettebø 23 Feb '03

23 Feb '03

>From: "Eduardo Chao" <efchao(a)hotmail.com> > I am a new suscriber to the list. > I want to report what I consider a bug in lexical_cast conversion template. > First, I wanted to use it to convert things to std::string (Target). > It throws a bad_lexical_cast_exception when I pass an empty std::string object (one > that is default-constructed or constructed with "") as the Source argument. > It throws it because the condition (interpreter >> result ) evaluates to > false. Yes, this is a bug in the current version, see (http://www.boost.org/libs/conversion/lexical_cast.htm#future) There's a proposition which fixes this and other problems here (http://groups.yahoo.com/group/boost/files/lexical_cast_proposition/lexical_ cast_proposition.zip). It's scheduled to be reviewed by the author, Kevlin Henney, or Björn Karlsson (Boost's maintenance wizard), before Boost release 1.30. If they find it ok, a notice will also be posted at the Boost list, so that others may give feedback before the release, as well. > My solution was to specialize the function template this way: > > template<> lexical_cast<std::string>(const std::string &str) > { > return str; > } The proposition handles it in a similar way. However, it's not possible to partially specialise function templates (e.g. to handle all T -> std::basic_string conversions), so function template overloading is used, instead. This is because it needs to handle conversion from any type to std::basic_string, as there may be other types which output empty strings or whitespace, as well. > but it is not so general to support const std::string or const std::string& > as Target type or perhaps std::string or const std::string etc as Source. > Correct me if I am wrong, so I learn from you more experienced Boost (and then C++) users. No, you're right. However, it's only necessary to handle T -> std::basic_string (not cv-qualification or reference) in this case, because: lexical_cast<std::string>(...); // Ok lexical_cast<const std::string>(...); // Error, can't write to a const string lexical_cast<const std::string &>(...); // Error, can't return a reference to the result (it would then return a dangling reference, as the result would be a temporary) lexical_cast<std::string>(const_cast<const std::string>(...)); // Ok, top-level cv-qualifiers are ignored when matching the call Regards, Terje

1 0

random/histogram.cpp
by agiatojon <JonAgiato＠nyc.rr.com> 23 Feb '03

23 Feb '03

Hello all, I have been unable to successfully compile histogram.cpp in the random library folder, version 1_29_0, using Visual Studio.NET. I obtain the following errors: c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(49): warning C4267: 'argument' : conversion from 'size_t' to 'std::streamsize', possible loss of data c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(101): error C2065: 'gen' : undeclared identifier c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2066: cast to function type is illegal c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2059: syntax error : ')' c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.base' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(111): error C2228: left of '.sum' must have class/struct/union type c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(113): error C2228: left of '.squaresum' must have class/struct/union type It appears to me that all of these messages will go away when the second one, c:\Documents and Settings\Agiato\My Documents\Visual Studio Projects\histogramTest\driver.cpp(97): error C2061: syntax error : identifier 'base', is corrected. Any assistance is greatly apprechiated! Thank you. Jon Agiato JonAgiato(a)nyc.rr.com

1 0

[BGL] Using external edge properties
by yg-boost-users＠m.gmane.org 22 Feb '03

22 Feb '03

I have a graph which might change during it's lifetime. I want to attach external properties to this graph. Now, it seems like that in order to be able to attach external properties, I need to have an internal property with edge indices, ie that enumerates the edges. These indices need to be continuous as I gather, since they are used to index for instance a vector of num_edges() elements. Does this mean that I have to re-enumerate all edges if I remove one? This seems to me very cumbersome and also time consuming if the graph is large and changes a lot. Is there another way? Björn Lindberg

2 2

bug in shared_ptr
by Simone Finotti 22 Feb '03

22 Feb '03

hi all, I don't know if this is the right place to report bug, if it's not please forgive me. I was trying to use boost/shared_ptr.hpp class, so I defined BOOST_NO_EXCEPTIONS because my compiler doesn't support C++ exceptions, but I receive this error: ..\..\boost_1_29_0\boost/detail/shared_count.hpp(122) : error C2039: 'use_count_is_zero' : is not a member of 'boost' ..\..\boost_1_29_0\boost/detail/shared_count.hpp(122) : error C2065: 'use_count_is_zero' : undeclared identifier in detail, here's an excerpt from shared_count.hpp, where the compiler gives the error: void add_ref() { #ifdef BOOST_HAS_THREADS mutex_type::scoped_lock lock(mtx_); #endif if(use_count_ == 0 && weak_count_ != 0) boost::throw_exception(boost::use_count_is_zero()); ++use_count_; ++weak_count_; } use_count_is_zero is not defined because it's defined, in the same file, as: #ifndef BOOST_NO_EXCEPTIONS class use_count_is_zero: public std::exception { public: virtual char const * what() const throw() { return "boost::use_count_is_zero"; } }; #endif is there a way to make it work? -- Simone

2 1

Can one "nest" regular expressions ?
by yg-boost-users＠m.gmane.org 22 Feb '03

22 Feb '03

Hello folks, I believe my question applies to regular expression libraries generally and not just to regexp++. I want to know if it is possible to refer to or use one regular expression within another. What I wish to do is parse a string of html code for img tags, and if they have the clause ALT="whatever" replace the whole image tag with 'whatever'. So I decided to make regular expression for an image tag which had an ALT part, and have a sub-match on the contents of quoted part of the ALT. (I broke this up a bit, explaining what each part is for . . .) This will match img tags: static const boost::regex find_imgs(" <\\s*img Matches <, 0 or many whitespace, IMG \\s+src\\s* Matches 1 or more whitespace, SRC, 0 or many whitespace =\\s* Matches = followed by 0 or more whitespace \"\\s* Matches " followed by 0 or more whitespace ([^\"]*) Matches any number of characters that are not " ([^>]*>) Matches any number of chars that not >, followed by a > ", boost::regbase::normal | boost::regbase::icase); Ok, so now look at this one. I'm trying to do the same as above except I want to sub-match the quoted part of the alt part so I can use it. I can't do "anything except the word 'alt'" because it will interpret the [^(alt)] as "anything except 'a', 'l', or 't'". static const boost::regex find_imgs_with_alt(" <\\s*img Matches <, 0 or many whitespace, IMG \\s+src\\s* Matches 1 or more whitespace, SRC, 0 or many whitespace =\\s* Matches = followed by 0 or more whitespace \"\\s* Matches " followed by 0 or more whitespace [^\"]* Matches any number of chars not " \\s+ Matches 1 or more whitespace [^alt]* I would like match anything except the word ALT, but the regexp stuff interprets this as anything but 'a', 'l', or 't' alt\\s*= Matches ALT, 0 or whitespace, = \"(^\")\" Matches ", anything except a " as a group that I can reference, then another " [^>]*> Matches any number of chars not >, followed by a > ", boost::regbase::normal | boost::regbase::icase); So what I want to do is make another regular expression which matches "alt", and in the part that says [^alt]* do instead something like [^@alt]* where '@' would indicate that 'alt' was the name of another regular expression, such as static const boost::regex alt("alt", boost::regbase::normal | boost::regbase::icase); I can see how to do what I want to do without this; I would get the whole IMG tag and do a separate regexp_search on the match. But it seems to make it so much easier if it were possible, especially leaving me with fewer lines of regular expression code to have bugs in. If this is possible I'd like to know. Thanks in advance, and I'll post the regular expressions I end up using here if anyone might find them of use. --Rob

4 9

lexical_cast bug.
by Eduardo Chao 22 Feb '03

22 Feb '03

Hello, I am a new suscriber to the list. I want to report what I consider a bug in lexical_cast conversion template. First, I wanted to use it to convert things to std::string (Target). It throws a bad_lexical_cast_exception when I pass an empty std::string object (one that is default-constructed or constructed with "") as the Source argument. It throws it because the condition (interpreter >> result ) evaluates to false. My solution was to specialize the function template this way: template<> lexical_cast<std::string>(const std::string &str) { return str; } but it is not so general to support const std::string or const std::string& as Target type or perhaps std::string or const std::string etc as Source. Correct me if I am wrong, so I learn from you more experienced Boost (and then C++) users. That's all for now. Thanks in advance. Eduardo Chao. [Non-text portions of this message have been removed]

1 0

Testing Boost:threads on windows w/ cygwin/gcc help
by sam <samijackson＠yahoo.com> 21 Feb '03

21 Feb '03

Howdy, I have cygwin running on a WinXP box and am trying to get the threads up and running. I built the Boost.Threads and things look good. Then I try: "bjam -sTOOLS=gcc test" from the /lib/thread/test directory and the test fails with: <build> ...found 1203 targets... ...using 1 temp target... ...updating 181 targets... ...using <libs!thread!test/test_thread.test/gcc/debug/runtime-link-static/threa ding-multi>test_thread.run... succeeded-test-file ../../../libs/thread/test/bin/test_thread.test/gcc/debug/runtime-link- static/threading-multi/test_thread.test Syntax error: "fi" unexpected (expecting "then") <chomp/> echo "*" echo "***************** failed above test: test_thread ********************" echo "*" </build> My question is, how do I correctly get Boost to use either native or pthreads and pass the tests above? I've checked the FAQs, Googled and all that, but can't seem to find an answer. I'm sure it's easy, but can't get it right. thanks Sam

3 5

boost::mutex, Borland C++Bulder 6 and CodeGuard
by Russell Hind 21 Feb '03

21 Feb '03

I have been running into CodeGuard problems using boost 1.29.0 with BorlandC++Builder 6Pro update 2 and CodeGuard. The test project is a console app, multi-threading but no vcl (don't know if the VCL enabled affects it or not). The code is #include <boost/thread/mutex.hpp> int main(int argc, char* argv[]) { boost::mutex m; return 0; } I get a resource type mismatch on exit which is down to the mutes. I have linked directly with the source and found where the problem lies. It could be down to 2 places: a) boost allocates the mutex (mutex.cpp line 39) using the nowthrow operator new m_mutex = reinterpret_cast<void*>(new(std::nothrow) CRITICAL_SECTION); and then deletes it using the standard delete (mutex.cpp line 48) delete reinterpret_cast<LPCRITICAL_SECTION>(m_mutex); This causes slight problems as codeguard treats allocations from new and malloc differently to check you free the memory correctly. nothrow new uses malloc, so a standard delete is the incorrect way to free the mutex here from CodeGuards point of view. I have changed the delete to operator delete (reinterpret_cast<LPCRITICAL_SECTION>(m_mutex), std::nothrow); which calls the nothrow version of delete. Unfortunately, the next part of the problem: b) For some reason, the mutex is using the roguewave stl new.h which defines the nothrow operators as such (oldstl\new.h line 143) inline void * _RTLENTRY operator new (size_t size, const std::nothrow_t &nt) { size = size ? size : 1; return malloc(size); } (oldstl\new.h line 152) inline void _RTLENTRY operator delete (void *v, const std::nothrow_t &nt) { ::operator delete (v); // The standard operator doesn't throw any exceptions } Here, there is a conflict in the allocation and deallocation. changing line 154 to free(v); along with the change to mutex to use the nothrow version of delete fixes it so codeguard can be used. Looking in the stlport new, it forces us to use RogueWave's new because of these lines in stlport\new line 49 # if !defined (_STLP_NO_NEW_NEW_HEADER) # include _STLP_NATIVE_CPP_RUNTIME_HEADER(new) # else # include <new.h> # endif which makes it include roguewaves version of new. So C++Builder 6 is still reliant on roguewave stl even when set to use STLPort. Possible solutions are a) Make boost::thread use nothrow version of delete but this requires a fix in the borland/rogue wave header for the delete to make it use free. or b) mutex could use malloc and free directly for borland. Which would people prefer or can anyone think of another solution? Cheers Russell

2 1

Boost::Threads condition variable on Win32 and IO completion routines
by Russell Hind 21 Feb '03

21 Feb '03

The start of the do_wait() method of a boost::condition (in 1.29.0) for Win32 looks like this void condition::do_wait() { int res = 0; res = WaitForSingleObject(reinterpret_cast<HANDLE>(m_queue), INFINITE); assert(res == WAIT_OBJECT_0); This waits indefinitely until m_queue is signalled. Would it be safe to change this so the thread is alertable for IO completion routines? Something like int res = 0; while ((res = WaitForSingleObjectEx(reinterpret_cast<HANDLE>(m_queue), INFINITE, true)) == WAIT_IO_COMPLETION) { } assert (res == WAIT_OBJECT_0); We make fairly heavy use of Waitable Timers in our statemachines. The completion routine for a timer is called back in the context of the thread that started it, when the thread is alertable. WaitForSingleObject doesn't allow the thread to be alertable. We currently use this in our own thread (with Windows events) but are looking to update the message queue code and thread code to use boost. With out this change, it would currently break a lot of code if we were to use condition variables. Thanks Russell

3 2

Regex++
by Yutaka Emura 21 Feb '03

21 Feb '03

Hi John "(?!foo)bar" matches "bar" in the last three lines of the following: foobar ??bar barfoo bar?? bar Why doesn't it match "bar" in all the lines? Yutaka Emura --------------- > I am using RegEx in Boost v1.29.0. > (?= ) and (?! ) expressions do not seem to work at a certain > condition. > > In the following example, "(?=a)b" should match "b" in "xyzabcdefg", > but does not. Which is correct: (?=a) is a forward lookahead *possitive* assertion, so (?=a)b can never match anything since the next character can't be both an 'a' and a 'b' at the same time! > Similarly, "(?!a)b" should not match "b" in "xyzabcdefg" but it does. It should match: (?!a) will match anything except 'a' so (?!a)b will match the next 'b' that it finds.

2 2

UBLAS: postincrement broken on VC60 ?
by speedsnaii <speedsnaii＠yahoo.de> 21 Feb '03

21 Feb '03

When I specify the following: matrix<double>::iterator1 it; it++; I get: (sorry for the paste of the complete error, I can't figure out what is really relevant; ++it works however) ============================================================ c:\program files\boost\boost\numeric\ublas\iterator.hpp(324) : error C2059: syntax error : 'static_cast' S:\test\ublas\ublas.cpp(30) : see reference to function template instantiation 'class boost::numeric::ublas::matrix<double,struct boost::numeric::ublas::row_major,class boost::numeric::ublas::unbounded_array<double> >::iterator1 __cdecl boos t::numeric::ublas::operator ++(struct boost::numeric::ublas::random_access_iterator_base<struct boost::numeric::ublas::dense_random_access_iterator_tag,class boost::numeric::ublas::matrix<double,struct boost::numeric::ublas::row_major,class boost::n umeric::ublas::unbounded_array<double> >::iterator1,double,int> &,int)' being compiled c:\program files\boost\boost\numeric\ublas\iterator.hpp(325) : error C2664: '__thiscall boost::numeric::ublas::matrix<double,struct boost::numeric::ublas::row_major,class boost::numeric::ublas::unbounded_array<double> >::iterator1::boost::numeric::u blas::matrix<double,struct boost::numeric::ublas::row_major,class boost::numeric::ublas::unbounded_array<double> >::iterator1(const class boost::numeric::ublas::matrix<double,struct boost::numeric::ublas::row_major,class boost::numeric::ublas::unbou nded_array<double> >::iterator1 &)' : cannot convert parameter 1 from 'class boost::numeric::ublas::matrix<double,struct boost::numeric::ublas::row_major,class boost::numeric::ublas::unbounded_array<double> >::iterator1 &(void)' to 'const class boos t::numeric::ublas::matrix<double,struct boost::numeric::ublas::row_major,class boost::numeric::ublas::unbounded_array<double> >::iterator1 &' Context does not allow for disambiguation of overloaded function S:\test\ublas\ublas.cpp(30) : see reference to function template instantiation 'class boost::numeric::ublas::matrix<double,struct boost::numeric::ublas::row_major,class boost::numeric::ublas::unbounded_array<double> >::iterator1 __cdecl boos t::numeric::ublas::operator ++(struct boost::numeric::ublas::random_access_iterator_base<struct boost::numeric::ublas::dense_random_access_iterator_tag,class boost::numeric::ublas::matrix<double,struct boost::numeric::ublas::row_major,class boost::n umeric::ublas::unbounded_array<double> >::iterator1,double,int> &,int)' being compiled c:\program files\boost\boost\numeric\ublas\iterator.hpp(326) : error C2563: mismatch in formal parameter list S:\test\ublas\ublas.cpp(30) : see reference to function template instantiation 'class boost::numeric::ublas::matrix<double,struct boost::numeric::ublas::row_major,class boost::numeric::ublas::unbounded_array<double> >::iterator1 __cdecl boos t::numeric::ublas::operator ++(struct boost::numeric::ublas::random_access_iterator_base<struct boost::numeric::ublas::dense_random_access_iterator_tag,class boost::numeric::ublas::matrix<double,struct boost::numeric::ublas::row_major,class boost::n umeric::ublas::unbounded_array<double> >::iterator1,double,int> &,int)' being compiled Error executing cl.exe. ============================================================

2 2

Crash with regex, setlocale() return 0 on CW
by msternerkthse <msterner＠kth.se> 20 Feb '03

20 Feb '03

The following code on line 841 of c_regex_traits.cpp in the regex library caused a crash when I used it in CodeWarrior 8.1 under OSX: std::string l(std::setlocale(LC_CTYPE, 0)); Afaict the crash was caused by setlocale() returning 0. To fix this I had to resort to the following ugly hack: namespace std { const char* mysetlocale(int, const char*) { return "C"; } }; #include "boost/regex.hpp" #define setlocale mysetlocale #include "boost/regex/src.cpp" The C locale was used because I had BOOST_REGEX_USE_C_LOCALE defined. I didn't want to use the C++ locale since it doesn't even provide the basic 0x00-0xFF unicode case mapping that's built into the C locale (due to limited locale support in CW I guess). I'm using the wregex class. Mikael Sterner

3 2

UBLAS: copy on write for matrix & vector?
by speedsnaii <speedsnaii＠yahoo.de> 19 Feb '03

19 Feb '03

A question on use of the matrix and vector classes: Should I: matrix<double> foo(const matrix<double> a) { matrix >double> r; ... return r; } or void foo(matrix<double>& r, const matrix<double> a) { ... } In other words: is it expensive to construct the temporary in case one? As I understand, the class would need an underlying 'copy on write' to be cheap, similar as strings do. I tried, to answer this question from the documentation, but sorry I did not get through. Thank you for help. Roland

4 8

Using boost::test without library-supplied main? (newbie)
by Hannu Helminen 18 Feb '03

18 Feb '03

Hi All! Can the boost::test used without the library-provided main()? Rationale: - the application does not have main() but WinMain() - it is built on top of MFC so even the WinMain() is already supplied by the framework - I would like to control the execution of unit tests myself, e.g. include a menu item "Run unit tests now" Can anyone help me? Hannu Helminen Finland

2 1