July 2007 - Boost-users - lists.boost.org

Program Options: Documentation about response files out of date?
by Olaf van der Spek 20 Jul '07

20 Jul '07

Hi, [1] says: > The library does not provide direct support for response files, so you'll need to write some extra code. But this code does the trick without much extra code: std::ifstream is(vm["conf_file"].as<std::string>().c_str()); po::store(po::parse_config_file(is, desc), vm); Or is a response file something else? In that case, maybe that should be mentioned, as I think for lots of users this is enough. [1] http://boost.org/doc/html/program_options/howto.html#id1592676

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[Optional 1.33.1] Assignment of convertible optional to an optional
by contact＠dword.dk 20 Jul '07

20 Jul '07

Hi, >From the documentation I think this should be possible: optional<unsigned short> us; optional<unsigned int> ui; ui = us; In this case it should just leave ui uninitialized. But instead I hit the assertion in reference_const_type get() const, because there is a call to rhs.get() in the operator=(). Is this a bug, or am I doing something wrong? I'm using MSVC7.1. Best regards, Christian Larsen

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[ptr_container] "Cannot access private member..." compile error
by Dan Thill 20 Jul '07

20 Jul '07

Seeking ptr_container guru, My first usage of ptr_container, and I fear I'm missing something obvious. I keep getting the following compile error: -------------------------------------------- Z:\Tools\boost\boost_1_34_0\boost/ptr_container/detail/associative_ptr_container.hpp(202) : error C2248: 'boost::ptr_container_detail::reversible_ptr_container<Config,CloneAllocator>::reversible_ptr_container' : cannot access private member declared in class 'boost::ptr_container_detail::reversible_ptr_container<Config,CloneAllocator>' with [ Config=boost::ptr_container_detail::set_config<Abstract_Record,std::set<void *,boost::void_ptr_indirect_fun<std::less<Abstract_Record>,Abstract_Record>,std::allocator<void *>>>, CloneAllocator=boost::heap_clone_allocator ] Z:\Tools\boost\boost_1_34_0\boost/ptr_container/detail/reversible_ptr_container.hpp(286) : see declaration of 'boost::ptr_container_detail::reversible_ptr_container<Config,CloneAllocator>::reversible_ptr_container' with [ Config=boost::ptr_container_detail::set_config<Abstract_Record,std::set<void *,boost::void_ptr_indirect_fun<std::less<Abstract_Record>,Abstract_Record>,std::allocator<void *>>>, CloneAllocator=boost::heap_clone_allocator ] This diagnostic occurred in the compiler generated function 'boost::ptr_container_detail::associative_ptr_container<Config,CloneAllocator>::associative_ptr_container(const boost::ptr_container_detail::associative_ptr_container<Config,CloneAllocator> &)' with [ Config=boost::ptr_container_detail::set_config<Abstract_Record,std::set<void *,boost::void_ptr_indirect_fun<std::less<Abstract_Record>,Abstract_Record>,std::allocator<void *>>>, CloneAllocator=boost::heap_clone_allocator ] -------------------------------------------- My container is declared thusly: boost::ptr_set<Abstract_Record> And the relevant parts of -------------------------------------------- class Abstract_Record { public: Abstract_Record(); Abstract_Record* clone(); virtual bool operator<(const Abstract_Record&); private: Abstract_Record(const Abstract_Record&); }; -------------------------------------------- I'm having trouble deciphering the error message. I declared a new_clone() function as described in the docs. I also tried writing my own CloneAllocator. Neither have any effect. I would be very grateful for some insight, or even a nudge with a cluebat. -Dan

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[boost.test] Test suits and autoregistration
by Stefan Shishkov 20 Jul '07

20 Jul '07

Hi, I'm using boost 1.33.1, but the question applies to 1.34 too. Is it possible to create tests suites that contain test cases from different translation units using only auto registration? Ex: in file1.cpp BOOST_AUTO_TEST_SUITE(BigSuite); auto-register test suites and cases here... BOOST_AUTO_TEST_SUITE_END(); in file2.cpp BOOST_AUTO_TEST_SUITE(BigSuite); auto-register other test suites and cases here... BOOST_AUTO_TEST_SUITE_END(); As result only one suite with name "BigSuite" should be registered. Best regards, Stefan

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[program_options] Short Option Name
by Christian Henning 20 Jul '07

20 Jul '07

Hi there, I cannot get the short option name feature to work. For some reason an exception is being thrown when I use the short name. I'm using boost 1.34 on MSVC 8. Here is what I'm doing: #include <boost\program_options.hpp> using namespace std; using namespace boost; namespace po = boost::program_options; int main( int argc, char* argv[] ) { string input; po::options_description settings( "" ); settings.add_options() ( "input,I" , po::value< string >( &input ) ->default_value( "" ) , "" ); po::options_description options; options.add( settings ); po::variables_map variables; store( parse_command_line( argc , argv , settings ) , variables ); notify( variables ); cout << input << endl; return 0; } Using --input="hello" works but not -I="hello". What am I overlooking? Thanks ahead, Christian

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"detail" namespace
by Chauhan, Vikas 20 Jul '07

20 Jul '07

Hi , Can you please advise , why boost has "detail" namespace? Is a kind of standard as most of the libraries also have a detail namespace for eg: boost::asio::detail, boost::archive::detail, boost::format::detail and so on... Thanks, Vikas

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Problem with boost::transform_iterator, std::pairs and templates.
by Manuel Holtgrewe 19 Jul '07

19 Jul '07

Hi, I have a problem using the Boost.Iterators library correctly. The following minimal example does neither compile with GCC 4.2 nor with a current ICC 10.0 version. It seems that putting a boost::transform_iterator inside a pair makes it impossible to retrieve its value again using std::iterator_traits. I would welcome a proposal how to resolve the problem. I get the bug when using transform_iterator together with the MCSTL (Multi Core STL) and thus cannot change the internals. I would thus like to know if and how I can make the following work without touching the inner() and outer() functions themselves since I do not have the possibility to change the library code itself. Am I using boost::transform_iterator incorrectly? Kind Regards, Manuel == File Source == #include <iostream> #include <vector> #include <functional> #include <boost/iterator/transform_iterator.hpp> class plus_two : public std::unary_function<int, int> { public: int operator()(int x) const { return x + 2; } }; template <class Pair> void inner(Pair pair) { typedef typename Pair::first_type Iterator; typedef typename std::iterator_traits<Iterator>::value_type T; Pair p = pair; T *x = &p.first[0]; (void)x; } template<class InIterator> void outer(InIterator begin, InIterator end) { typedef typename std::iterator_traits<InIterator>::value_type ValueType; inner(std::make_pair(begin, end)); } int main(void) { int in[10] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }; outer( // broken boost::make_transform_iterator(in, plus_two()), boost::make_transform_iterator(in + 10, plus_two())); outer(in, in+10); // working return 0; } == GCC 4.2.0 Output == user@host:~/tmp> gcc-4.2.0 --version gcc-4.2.0 (GCC) 4.2.0 Copyright (C) 2007 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. user@host:~/tmp> gcc-4.2.0 conflict.cpp conflict.cpp: In function 'void inner(Pair) [with Pair = std::pair<boost::transform_iterator<plus_two, int*, boost::use_default, boost::use_default>, boost::transform_iterator<plus_two, int*, boost::use_default, boost::use_default> >]': conflict.cpp:29: instantiated from 'void outer(InIterator, InIterator) [with InIterator = boost::transform_iterator<plus_two, int*, boost::use_default, boost::use_default>]' conflict.cpp:37: instantiated from here conflict.cpp:21: warning: taking address of temporary conflict.cpp:21: error: cannot convert 'boost::detail::operator_brackets_proxy<boost::transform_iterator<plus_t wo, int*, boost::use_default, boost::use_default> >*' to 'int*' in initialization == Intel C++ Compiler Output == user@host:~/tmp> icc -V Intel(R) C Compiler for applications running on Intel(R) 64, Version 10.0 Build 20070613 Package ID: l_cc_c_10.0.025 Copyright (C) 1985-2007 Intel Corporation. All rights reserved. FOR NON-COMMERCIAL USE ONLY user@host:~/tmp> icc conflict.cpp conflict.cpp(21): warning #1563: taking the address of a temporary T *x = &p.first[0]; ^ detected during: instantiation of "void inner(Pair) [with Pair=std::pair<boost::transform_iterator<plus_two, int *, boost::use_default, boost::use_default>, boost::transform_iterator<plus_two, int *, boost::use_default, boost::use_default>>]" at line 29 instantiation of "void outer(InIterator, InIterator) [with InIterator=boost::transform_iterator<plus_two, int *, boost::use_default, boost::use_default>]" at line 35 conflict.cpp(21): error: a value of type "boost::detail::operator_brackets_proxy<boost::transform_iterator<plus_t wo, int *, boost::use_default, boost::use_default>> *" cannot be used to initialize an entity of type "T={int} *" T *x = &p.first[0]; ^ detected during: instantiation of "void inner(Pair) [with Pair=std::pair<boost::transform_iterator<plus_two, int *, boost::use_default, boost::use_default>, boost::transform_iterator<plus_two, int *, boost::use_default, boost::use_default>>]" at line 29 instantiation of "void outer(InIterator, InIterator) [with InIterator=boost::transform_iterator<plus_two, int *, boost::use_default, boost::use_default>]" at line 35 compilation aborted for conflict.cpp (code 2)

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[mpl]problems with mpl::set
by Brian Simpson 19 Jul '07

19 Jul '07

I'm having problems compiling non-explicitly-declared mpl::set types. Here's an example: <block1> typedef set<char> set1_t; BOOST_MPL_ASSERT_RELATION(size<set1_t>::value, ==, 1); //test iterating through the mpl.set: typedef begin<set1_t>::type set1_itr0_t; BOOST_MPL_ASSERT((is_same<deref<set1_itr0_t>::type, char>::type)); typedef next<set1_itr0_t>::type set1_itr1_t; BOOST_MPL_ASSERT((is_same<set1_itr1_t, end<set1_t>::type>::type)); </block1> In block1, I declare a set with one type, char, and then iterate over it. This code compiles, as expected. <block2> typedef set<> empty_set; BOOST_MPL_ASSERT_RELATION(size<empty_set>::value, ==, 0); typedef insert<empty_set, char>::type set2_t; BOOST_MPL_ASSERT_RELATION(size<set2_t>::value, ==, 1); //test iterating through the mpl.set: typedef begin<set2_t>::type set2_itr0_t; BOOST_MPL_ASSERT((is_same<deref<set2_itr0_t>::type, char>::type)); typedef next<set2_itr0_t>::type set2_itr1_t;//compile error at this line BOOST_MPL_ASSERT((is_same<set2_itr1_t, end<set2_t>::type>::type)); </block2> In block2, I declare a set with no types, then insert a char type, then iterate over the resulting sequence. At the line where I get the second iterator, I get a compile error: <error_text> boost\mpl\set\aux_\iterator.hpp(52) : error C3083: 'next_': the symbol to the left of a '::' must be a type boost\mpl\eval_if.hpp(41) : see reference to class template instantiation 'boost::mpl::next<T>' being compiled with [ T=boost::mpl::s_iter<set2_t,boost::mpl::set<boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na>> ] boost\mpl\set\aux_\iterator.hpp(56) : see reference to class template instantiation 'boost::mpl::eval_if<C,F1,F2>' being compiled with [ C=boost::mpl::has_key<set2_t,boost::mpl::set<boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na>::type>, F1=boost::mpl::identity<boost::mpl::s_iter<set2_t,boost::mpl::set<boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na>>>, F2=boost::mpl::next<boost::mpl::s_iter<set2_t,boost::mpl::set<boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na,boost::mpl::na>>> ] source.cpp(120) : see reference to class template instantiation 'boost::mpl::next<T>' being compiled with [ T=set2_itr0_t ] </error_text> MSVS 8.0 is the compiler(_MSC_VER == 1400). Am I missing an obvious error in my code? Thanks! _________________________________________________________________ Need a break? Find your escape route with Live Search Maps. http://maps.live.com/default.aspx?ss=Restaurants~Hotels~Amusement%20Park&cp…

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Finding the correct library to link (feature request for pkg-config support)
by Roger Leigh 19 Jul '07

19 Jul '07

Hi folks, [I've posted this to both user and development lists, because I'm not sure which is most appropriate in this case.] I make use of several Boost libraries in my schroot program (svn://svn.debian.org/svn/buildd-tools/trunk/schroot) This project, like many, utilises GNU Autoconf and Automake for its build system. I need to determine how to link with the Boost libraries in order to build the programs in the project. This is an issue for many projects which want to link with a Boost library. To illustrate my problem: ls -l /usr/lib/libboost_regex-*.so /usr/lib/libboost_program_options-*.so lrwxrwxrwx 1 root root 45 2007-07-08 11:48 /usr/lib/libboost_program_options-gcc41-1_34.so -> libboost_program_options-gcc41-1_34.so.1.34.0 lrwxrwxrwx 1 root root 48 2007-07-08 11:48 /usr/lib/libboost_program_options-gcc41-mt-1_34.so -> libboost_program_options-gcc41-mt-1_34.so.1.34.0 lrwxrwxrwx 1 root root 41 2007-07-08 11:48 /usr/lib/libboost_program_options-mt.so -> libboost_program_options-gcc41-mt-1_34.so lrwxrwxrwx 1 root root 38 2007-07-08 11:48 /usr/lib/libboost_program_options-st.so -> libboost_program_options-gcc41-1_34.so lrwxrwxrwx 1 root root 35 2007-07-08 11:47 /usr/lib/libboost_regex-gcc41-1_34.so -> libboost_regex-gcc41-1_34.so.1.34.0 lrwxrwxrwx 1 root root 38 2007-07-08 11:47 /usr/lib/libboost_regex-gcc41-mt-1_34.so -> libboost_regex-gcc41-mt-1_34.so.1.34.0 lrwxrwxrwx 1 root root 31 2007-07-08 11:47 /usr/lib/libboost_regex-mt.so -> libboost_regex-gcc41-mt-1_34.so lrwxrwxrwx 1 root root 28 2007-07-08 11:47 /usr/lib/libboost_regex-st.so -> libboost_regex-gcc41-1_34.so Unlike every other library on my system, the Boost libraries have the compiler (gcc41) and threading model (mt|st) and so on embedded *in the library name*. This makes it impossible to discover in an automatic fashion. Since this is free software anyone can download and build, I don't know what the compiler/toolchain will be, let alone what abbreviation Boost has chosen for it. I expect that Autoconf will set up such things appropriately. The only means I have are the libboost_program_options-mt.so, libboost_program_options-st.so (and so on for all the libraries) symbolic links which the Debian maintainer has helpfully provided. However, these are not portable, and are so not a good solution. They are, however, the only available solution at the moment. To further show the problem I am having, this is part of my configure.ac Autoconf template: ---configure.ac---- AC_CHECK_HEADERS([tr1/memory]) AC_CHECK_HEADERS([boost/shared_ptr.hpp],, [ if test $ac_cv_header_tr1_memory = yes; then : else AC_MSG_ERROR([Boost.shared_ptr (Boost C++ Libraries) is not installed, but is required by schroot]) fi]) AC_CHECK_HEADERS([tr1/tuple]) AC_CHECK_HEADERS([boost/tuple/tuple.hpp],, [ if test $ac_cv_header_tr1_memory = yes; then : else AC_MSG_ERROR([Boost.Tuple (Boost C++ Libraries) is not installed, but is required by schroot]) fi]) AC_CHECK_HEADERS([boost/format.hpp],, [AC_MSG_ERROR([Boost.Format (Boost C++ Libraries) is not installed, but is required by schroot])]) AC_CHECK_HEADERS([boost/program_options.hpp],, [AC_MSG_ERROR([Boost.Program_options (Boost C++ Libraries) is not installed, but is required by schroot])]) AC_CHECK_HEADERS([boost/type_traits.hpp],, [AC_MSG_ERROR([Boost.TypeTraits (Boost C++ Libraries) is not installed, but is required by schroot])]) AC_MSG_CHECKING([for boost::program_options::variables_map in -lboost_program_options-st]) saved_ldflags="${LDFLAGS}" LDFLAGS="${LDFLAGS} -lboost_program_options-st" AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <boost/program_options.hpp>], [boost::program_options::variables_map::variables_map dummy()])], [AC_MSG_RESULT([yes]) BOOST_LIBS="${BOOST_LIBS} -lboost_program_options-st"], [AC_MSG_RESULT([no]) AC_MSG_FAILURE([libboost_program_options (Boost C++ Libraries) is not installed, but is required by schroot])]) LDFLAGS="${saved_ldflags}" AC_MSG_CHECKING([for boost::program_options::options_description::options() in -lboost_program_options-st]) saved_ldflags="${LDFLAGS}" LDFLAGS="${LDFLAGS} -lboost_program_options-st" AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <boost/program_options.hpp>], [boost::program_options::options_description testgrp("test group"); bool notused = testgrp.options().empty(); ])], [AC_MSG_RESULT([yes]) BOOST_PROGRAM_OPTIONS_DESCRIPTION_METHODS="current"], [AC_MSG_RESULT([no]) BOOST_PROGRAM_OPTIONS_DESCRIPTION_METHODS="old"]) LDFLAGS="${saved_ldflags}" AH_TEMPLATE(BOOST_PROGRAM_OPTIONS_DESCRIPTION_OLD, [Set if boost::program_options::options_description::options() is not available]) if test "$BOOST_PROGRAM_OPTIONS_DESCRIPTION_METHODS" = "old"; then AC_DEFINE(BOOST_PROGRAM_OPTIONS_DESCRIPTION_OLD, 1) fi AC_MSG_CHECKING([for boost::regex in -lboost_regex-st]) saved_ldflags="${LDFLAGS}" LDFLAGS="${LDFLAGS} -lboost_regex-st" AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <boost/regex.hpp>], [boost::regex("^foo[bar]$")])], [AC_MSG_RESULT([yes]) BOOST_LIBS="${BOOST_LIBS} -lboost_regex-st"], [AC_MSG_RESULT([no]) AC_MSG_FAILURE([libboost_regex (Boost C++ Libraries) is not installed, but is required by schroot])]) LDFLAGS="${saved_ldflags}" AC_SUBST([BOOST_LIBS]) ---configure.ac---- As you can see, that's quite a bit of complexity. It also includes code to work around a backwards compatibility issue in Boost.Program_options. However, it needs to know the library name in order to link the test code, and I'm still needing to use a non-standard name in order to do that. It would be great if Boost would provide a mechanism to allow such discovery. Such a mechanism already exists, and is called "pkg-config". By installing a small file in LIBDIR/pkgconfig for each Boost library, the pkg-config tool or PKG_CHECK_MODULES Autoconf macro may be used to query this information. As an example: ---- boost-regex-mt.pc ---- prefix=/usr exec_prefix=${prefix} libdir=${exec_prefix}/lib includedir=${prefix}/include Name: boost-regex-mt Description: Boost C++ Regular Expression Library (multi-threaded) Version: 1.34.0 Libs: -L${libdir} -lboost_regex-gcc41-mt-1_34 Libs.private: -licui18n -licuuc -lrt -lm Cflags: -I${includedir} -pthread ---- boost-regex-mt.pc ---- You can generate this from a template: ---- boost-regex-mt.pc.in ---- prefix=PREFIX exec_prefix=EPREFIX libdir=LIBDIR includedir=INCLUDEDIR Name: boost-regex-mt Description: Boost Regular Expression Library (multi-threaded) Version: VERSION Libs: -L${libdir} LIBRARY_NAME Libs.private: LIBRARY_DEPENDENCIES [for static linking] Cflags: -I${includedir} THREAD_OPTIONS_FOR_COMPILER ---- boost-regex-mt.pc.in ---- where the capitalised names are where you would substitute in the system- and compiler-specific options. It looks like bjam could probably make this a single rule all libraries could make use of. For such a setup, all that configure script above could be mostly reduced to PKG_CHECK_MODULES([boost-regex-st]) PKG_CHECK_MODULES([boost-program-options-st]) I don't know how bjam works, but I do this with Autoconf as a file generated by config.status, but it could also be generated by make with a simple sed command. I guess you could do the bjam equivalent, whatever that might be. I have had a look at the sources to try to implement this, but I am afraid I lack the bjam expertise to do it. You may find much more detailed discussion of these issues at http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=424038 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=424666 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=425264 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=428419 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=350539 Some of these are due to Debian-specific issues (a change to the symlink name), but the root cause is the inability to identify the Boost library names in an automated fashion. Regards, Roger -- .''`. Roger Leigh : :' : Debian GNU/Linux http://people.debian.org/~rleigh/ `. `' Printing on GNU/Linux? http://gutenprint.sourceforge.net/ `- GPG Public Key: 0x25BFB848 Please GPG sign your mail.

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[Boost.Any] Are there visitors for boost::any?
by Rydinare 19 Jul '07

19 Jul '07

Hi all. I was curious to see if there is or will be support for the use of the visitor pattern with boost::any? I think it would be very useful. I thought I had read that there was an experimental boost::any visitor at some point, but I couldn't find it. Please let me know. Thanks. --------------------------------- Looking for a deal? Find great prices on flights and hotels with Yahoo! FareChase.

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