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A question on switch_statement. Can any one with kindness help me?
by fmingu 05 Jul '09

05 Jul '09

I am using Dev-C++ with boost lambda expression, and I wrote the following lines: ................ int result,switchvalue; .............. (switch_statement(_1, case_statement<1> (var(result)=0), case_statement<2> (var(result)=1), case_statement<3> (var(result)=constant(value)), default_statement (var(std::cout)<<"wrong") ))(switchvalue); but the complier told me that: instantiated from `Arg::sig<boost::tuples::tuple<A&, B&, C&, Env&, boost::tuples::null_type, boost::tuples::null_type,.......... instantiated from `RET boost::lambda::lambda_functor_base<boost::lambda::switch_action<5, boost::lambda::detail::case_label<Case0>, .................... instantiated from `T::sig<boost::tuples::tuple<A&, boost::tuples::null_type, boost::tuples::null_type, ......... instantiated from here And I do not know where is wrong and how to correct it. By the way, can I use make_const(switchvalue) or constant(switchvalue) instead of switchvalue? Can any one with kindness help me?

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[Boost.Test] Error: Non-aligned pointer being freed
by Sebastian Hauer 05 Jul '09

05 Jul '09

Hello Boost Users, when running my unit tests on Mac OS X compiled with darwin gcc 4.2.1 for x86_64 I am getting the following error messages printed out even though no testing error were detected. As a side note running the same unit test on Windows MSVC 8 or Solaris gcc 3.2 succeeds without issues, so this seems to be either gcc 4.2 or Mac OS X specific. --------------- hauer@gandalf:~/dev/shark4/utils$ bin/darwin-4.2.1/debug/address-model-64/architecture-x86/shark-utilstest_d Running 51 test cases... *** No errors detected shark-utilstest_d(45498) malloc: *** error for object 0x3000100301fb0: Non-aligned pointer being freed (2) *** set a breakpoint in malloc_error_break to debug shark-utilstest_d(45498) malloc: *** error for object 0x30001003020c0: Non-aligned pointer being freed (2) *** set a breakpoint in malloc_error_break to debug shark-utilstest_d(45498) malloc: *** error for object 0x3000100302200: non-page-aligned, non-allocated pointer being freed *** set a breakpoint in malloc_error_break to debug --------------- I then ran the test through gdb and set a breakpoint at malloc_error_break and took a backtrace as shown below: ---------------- Starting program: /Users/hauer/dev/shark/utils/bin/darwin-4.2.1/debug/address-model-64/architecture-x86/shark-utilstest_d warning: posix_spawn failed, trying execvp, error: 86 Reading symbols for shared libraries ++++++.. done Breakpoint 1 at 0x7fff83745a51 Running 51 test cases... *** No errors detected pirate-utilstest_d(45520) malloc: *** error for object 0x3000100300630: Non-aligned pointer being freed (2) *** set a breakpoint in malloc_error_break to debug Breakpoint 1, 0x00007fff83745a51 in malloc_error_break () (gdb) bt #0 0x00007fff83745a51 in malloc_error_break () #1 0x00007fff83740ad0 in szone_error () #2 0x00000001001655f8 in boost::unit_test::framework_impl::clear (this=0x1001c7600) at impl/framework.ipp:133 #3 0x0000000100165728 in boost::unit_test::framework_impl::~framework_impl (this=0x1001c7600) at impl/framework.ipp:122 #4 0x0000000100160d82 in __tcf_1 () at impl/framework.ipp:222 #5 0x00007fff8369d3dc in __cxa_finalize () #6 0x00007fff8369d2f2 in exit () #7 0x0000000100000ceb in start () ------------------ This point to framework_impl's clean() method: ------------------ void clear() { while( !m_test_units.empty() ) { test_unit_store::value_type const& tu = *m_test_units.begin(); // the delete will erase this element from map if( test_id_2_unit_type( tu.second->p_id ) == tut_suite ) delete (test_suite const*)tu.second; else delete (test_case const*)tu.second; // <-- Line 133 } } ----------------- I think test_case's dtor was made public in 1.39 but I guess this did not fix the problem at hand. Regards, Sebastian

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Re: [Boost-users] A question on overloaded function? Can anyone with kindness help me?
by fmingu 05 Jul '09

05 Jul '09

I do not understand the sentence: Ignore the "conversion to unsigned int" part. As you know, I am a new comer and quite puzzled about that. Does that mean to change the complier enviroment? Can you give me an example? Thank you for your kindness. 在2009-07-02，"Steven Watanabe" <watanabesj(a)gmail.com> 写道： >AMDG > >fmingu wrote: >> But how can I change the expression to be legal and usable? >> bind(&std::pow,constant(-1),bind(&IIPrimemap::size,var(primemapvec))); >> I tried : >> bind(&std::pow,constant(-1.0),bind<int>(&IIPrimemap::size,var(primemapvec))); >> and >> bind(&std::pow,constant(-1.0),ret<int>(bind(&IIPrimemap::size,var(primemapvec)))); >> even >> bind(&std::pow,constant(-1.0),ll_dynamic_cast<int>(bind(&IIPrimemap::size,var(primemapvec)))); >> But the complier told me that: >> cannot resolve overloaded function `pow' based on conversion to >> type `unsigned int' >> > >Ignore the "conversion to unsigned int" part. The compiler >doesn't know how to handle std::pow and gets itself confused. >The problem is &std::pow, not the inner bind expression. > >> I do not know how to solve now. >> Can anyone with kindness help me? >> >> >>> You can't pass the address of an overloaded function to >>> a function template like bind without casting it to the >>> correct function pointer type. >>> > >In Christ, >Steven Watanabe > 200万种商品,最低价格,疯狂诱惑你

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CRC: Set checksum value
by Chris Spencer 04 Jul '09

04 Jul '09

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi all, I am using the CRC library in my program and need some way to set the value of the checksum. I.e., crc_32_type crc; crc.set_value(somevalue); crc.checksum() == somevalue; Is this possible short of modifying the source? I can't see any way to do it from the documentation. Cheers, Chris. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.11 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkpPuCsACgkQ6iqRtkAADZh4ZQCdGz9UWj9+9W/1SPw/jqPKCuyi /QAAniLRlVhIqhsAwAHYMFLlyOSuzdbY =ZLwZ -----END PGP SIGNATURE-----

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[test] gcc 4.2.1 unused warnings reappear in 1.39
by Sebastian Hauer 04 Jul '09

04 Jul '09

Hello Boost Users, I just upgraded from boost 1.38 to 1.39 on Mac OS X with darwin gcc 4.2.1 and noticed the following warnings: "g++" -ftemplate-depth-128 -O0 -fno-inline -Wall -g -dynamic -no-cpp-precomp -gdwarf-2 -arch x86_64 -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_TEST_DYN_LINK -DSHARK_DEBUG -DSHARK_DYN_LINK -I"/Users/hauer/sys/boost_1_39-darwin-x86_64-xgcc42/include" -I"common/src" -I"utils/src" -c -o "utils/bin/darwin-4.2.1/debug/address-model-64/architecture-x86/test/shark/dtm/DateParserTest.o" "utils/test/shark/dtm/DateParserTest.cpp" /Users/hauer/sys/boost_1_39-darwin-x86_64-xgcc42/include/boost/test/floating_point_comparison.hpp:224: warning: ‘boost::test_tools::<unnamed>::check_is_close’ defined but not used /Users/hauer/sys/boost_1_39-darwin-x86_64-xgcc42/include/boost/test/floating_point_comparison.hpp:246: warning: ‘boost::test_tools::<unnamed>::check_is_small’ defined but not used Following the thread here: http://lists.boost.org/boost-users/2008/10/41326.php it seems that this was already something that got addressed a while ago and if I diff the header against 1.38 I notice this change for instance: namespace { -check_is_close_t const& check_is_close = unit_test::ut_detail::static_constant<check_is_close_t>::value; +check_is_close_t check_is_close; } Is there a reason why the static_constant template was removed and you reverted back to the original version? Regards, Sebastian PS: Below the original message from Gennadiy were he mentioned he applied the static_constant patch. On Fri, Nov 21, 2008 at 6:42 PM, Gennadiy Rozental<rogeeff(a)gmail.com> wrote: > Juergen Hunold <juergen.hunold <at> ivembh.de> writes: > >> On Wednesday 05 November 2008 19:20:37 Mat Marcus wrote: >> > On Mon, Oct 13, 2008 at 12:42 PM, Steven Watanabe <watanabesj <at> >> > gmail.com> >> > This trick seemed to work at first, but then when I ran the 1.37.0 >> > test tests I got: >> > >> > ..\..\libs\test\example\unit_test_example_10.cpp(75) : error C2039: >> > 'check_is_close' : is not a member of 'boost::test_tools' >> > ..\..\libs\test\example\unit_test_example_10.cpp(75) : error C2065: >> > 'check_is_close' : undeclared identifier >> >> Did you try my patch as described in #2390 ? > > I've checked in patch along the line of what you proposed. Let's see if > anything > breaks. > > Gennadiy > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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[utility] Anyone here using Intel 9.0 compiler + value_initialized?
by Niels Dekker - address until 2010-10-10 04 Jul '09

04 Jul '09

boost::value_initialized<T>, as included with the release version of Boost (current version: 1.39.0), has a conversion operator that breaks the principle of "logical constness": The member function itself is "const", but it returns a non-const reference to the data, T&. Four months ago, I fixed this issue on the development trunk [51355], replacing the conversion operator by a const and a non-const overload. The const overload returns a const reference to the data. (Ticket #2548.) After this fix, one specific version of a compiler yielded some compiler errors at the regression page: Intel 9.0 In fact it only yielded two compiler errors: only for implicitly conversions from value_initialized<NonPOD*>, and const value_initialized<NonPOD*>. Other conversions went well, for example, from const value_initialized<int> to const int&. Now I wonder, because Intel 9.0 is an old compiler version, and the regression failure occurs only in a very specific case, would it be acceptable to leave the fix in there, and have it shipped with an upcoming release version of Boost? Is anyone here likely to use the next version of Boost, including value_initialized<T>, on Intel 9.0? If so, would you find it acceptable to retrieve a reference to the data from value_initialized<T> by using the value_initialized::data() member function, or boost::get, instead of depending on implicit conversion? Note: Five days ago I committed a workaround for Intel 9.0 to the trunk [54502], removing the const-version of the overload. But it yielded many more Intel 9.0 errors (33!), as expected, on any attempt to convert a const value_initialized<T>. So does anyone here think this workaround is still useful? References: Ticket #2548, "Let's fix the logical constness of value_initialized!" https://svn.boost.org/trac/boost/ticket/2548 Utility/trunk regression page: www.boost.org/development/tests/trunk/developer/utility_.html [51355] Fix at the development trunk (4 months ago): https://svn.boost.org/trac/boost/changeset/51355 [54502] Intel 9.0 specific workaround (5 days ago): https://svn.boost.org/trac/boost/changeset/54502 Kind regards, -- Niels Dekker http://www.xs4all.nl/~nd/dekkerware Scientific programmer at LKEB, Leiden University Medical Center

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[Boost.Test] [1.38] Handling unexpected exceptions and system errors
by Greg Christopher 04 Jul '09

04 Jul '09

Hi, One of the things that sets boost apart from other frameworks is its ability to handle exceptions and report them. While I've used the BOOST_CHECK_THROW and BOOST_CHECK_EXCEPTION macros, I'd like a way to pass if an exception is thrown that we don't necessarily understand how to mention in the BOOST_CHECK_THROW or BOOST_CHECK_EXCEPTION macros. BOOST_CHECK_NO_THROW just makes sure no exception is thrown. In some ways it's an odd request to say "I expect some exception to be thrown that I do not care to specify", but that would work for us. In addition, it would be nice (and I bet it's already available) to be able to say "allow next test case to run in event of exception" or "allow next test suite to run In event of exception". Right now, all testing does seem to abort (none of the above macros are either present or coded in a way to match the system issue. Any tips on how to discover those values, or to go forward when some kind of exceptional condition is expected is appreciated. -Greg

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Query on implementing a lock manager
by dhruva 04 Jul '09

04 Jul '09

Hello, I am looking for a centralized or distributed lock manager. My needs are simple. I have names for each shared resource, I want to have advisory reader and writer locks on those named resources. I can implement it by having a server which serves all the lock requests. Each named lock will be a boost reader writer lock (which are implemented using atomic operations). Since lock requests come over TCPIP, the client (lock requester) will block till the server sends a response. Using non blocking sockets, the client can have a lock with time outs or async locks. If there is something similar available, I rather reuse than implement it from scratch. This requirement is to have some locking on files that intend to share using NFS and CIFS. Since NFS and CIFS servers are different, I will not get a common lock manager. I do not need sophisticated byte rane locking (fcntl), just a reader/writer lock on the file would do. Also, I ensure that the part of file path is unique and common across shares. This can be used as the resource name across the network. Any suggestions, ideas or links would be of real help. -dhruva Love Cricket? Check out live scores, photos, video highlights and more. Click here http://cricket.yahoo.com

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[Proto] Recreating an expression
by christophe henry 03 Jul '09

03 Jul '09

Thanks Eric for your fast answer! Unfortunately, this doesn't solve my problem. To make a very very long discussion long, here a small example showing the problem from another side: I have an expression wrapper called mp_terminal and I define terminals, but not in the documented way (which I suspect is the problem) but instead deriving from them (for convenience purposes), for example: struct True : mp_terminal<typename proto::terminal<guard_tag>::type> {...} These terminals are used with a simple grammar: struct BuildGuards : proto::or_< proto::when< proto::logical_or<BuildGuards,BuildGuards >, GuardOR<BuildGuards(proto::_left),BuildGuards(proto::_right)>() >, proto::when< proto::logical_and<BuildGuards,BuildGuards >, GuardAND<BuildGuards(proto::_left),BuildGuards(proto::_right)>() >, proto::when< proto::logical_not<BuildGuards >, GuardNOT<BuildGuards(proto::_value)>() >, proto::when < proto::terminal<guard_tag>, proto::_() > > {}; Then, expressions like: True()|| False() give the expected result (struct GuardOR<struct True,struct False>). Even True()&& (Dummy1() || !(False() || True())) give the expected result: struct GuardAND<struct True,struct GuardOR<struct Dummy1,struct GuardNOT<struct GuardOR<struct False,struct True> > > > But a "!" alone (meaning followed by just a terminal, not the other parts of the BuildGuards grammar) breaks all (as do all unary operators I tried), like !False() or True()|| !False(). !False() => struct GuardNOT<struct mp_terminal<struct boost::proto::exprns_::expr<struct boost::proto::tag::terminal,struct boost::proto::argsns_::term<struct guard_tag>,0> > > Notice that !(False() || True()) works! Now, if I do not derive from mp_terminal but instead proceed as documented, all works as expected: proto::terminal<True>::type True_; ... !False_ => correct result. Sadly, this documented usage is unpractical in my use case. So, supposing that I managed this easy grammar, I imagine that the usage I do of terminals (deriving from them) is not allowed. Then, why do most use cases work like a charm? Only unary operators seem to fail. Attached are 2 test files. V1 doesn't work in all cases while V2 does. I use 1.38. Thanks a lot! Christophe _________________________________________________________________ Windows Live™: Keep your life in sync. Check it out! http://windowslive.com/explore?ocid=TXT_TAGLM_WL_t1_allup_explore_012009

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detect if a type has a size_t member
by Hicham Mouline 03 Jul '09

03 Jul '09

Hello template <typename T> struct S { // how to detect T has a member static const size_t value ? // if T has value, define member of S, m1 of type T1, otherwise m2 of type T2 }; Regards,

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