September 2012 - Boost-users - lists.preview.boost.org

[boost.build] Problems getting PDB files withs DLLs
by Jonathan Jones 19 Sep '12

19 Sep '12

Hi all, I'm having problems getting PDB files built with the DLLs using Boost 1.49 and Visual Studio 2010. I have both debug-symbols=on and debug-store=database specified, but the PDB files are never built. Am I missing something? Thanks, Jon

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(newbie) is_regular_file vs. symlinks in boost::filesystem ?
by Christian Convey 18 Sep '12

18 Sep '12

I'm writing code that takes a file pathname as a command-line argument. My program doesn't care whether the pathname is for a regular file, or if it's a symlink that ultimately leads to a regular file. This seems like such a common usage pattern that I would have expected Boost to have a built-in solution to this problem. But I don't see one. At the moment it looks like I'll have to write code like this: my_path = argv[1]; while (my_path is a symlink) { set my_path to the target of the symlink; error out of a cycle or excessive indirection is detected; } if (! is_regualr_file( my_path )) { tell user there's a problem; } Do I really need to write code like this?

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using boost shared memory
by Dave Dyer 18 Sep '12

18 Sep '12

I'm contemplating using boost to implement inter process communication between a 32 bit process and a 64 bit process. I'm pretty sure there will be no problem at the raw bits level, but I suspect that if I attempt to use any of the higher order constructs, such as allocators or message queues, the disparate size of pointers will make hash of it. Does anyone have any experience (or advice) ?

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Crash in boost::function destructor in my thread pool implementation
by Marcin Adamski 18 Sep '12

18 Sep '12

Hi I am trying to implement thread pool in C++ using pthread and boost::function as a wrapper for any function that client would like to call in the worker thread. I want to encapsulate logic related to threads management in one object which is taking ownership of these threads. That means whenever this object is destroyed, threads must be stopped and cleaned up. I've been testing my code and it turns out that I get segmentation fault when I destroy WorkerThreadManager object while there is boost::function processed in worker thread. See the code in attachment and backtrace from GDB below. I don't really understand why it happens, as far as I know boost::function is copyable, so once I get a copy of it from the queue, I can pop() it and even destroy whole queue (I prooved that in some small test) and then call the function's copy. So why is destruction of std::queue< boost::function<void() > causing problems? Or maybe it is something else. (gdb) bt #0 0xb7ad33a0 in ?? () from /lib/i386-linux-gnu/libc.so.6 #1 0x0807d3a7 in boost::function0<void>::clear (this=0x858db48) at /home/marcin/intel_build/boost_1_42_0/boost/function/function_template.hpp:856 #2 0x0807d17b in boost::function0<void>::~function0 (this=0x858db48, __in_chrg=<optimized out>) at /home/marcin/intel_build/boost_1_42_0/boost/function/function_template.hpp:752 #3 0x0807cec5 in boost::function<void()>::~function(void) (this=0x858db48, __in_chrg=<optimized out>) at /home/marcin/intel_build/boost_1_42_0/boost/function/function_template.hpp:1043 #4 0x0807ced8 in std::_Destroy<boost::function<void ()> >(boost::function<void ()>*) (__pointer=0x858db48) at /usr/include/c++/4.6/bits/stl_construct.h:94 #5 0x0807c868 in std::_Destroy_aux<false>::__destroy<boost::function<void ()>*>(boost::function<void ()>*, boost::function<void ()>*) (__first=0x858db48, __last=0x858d928) at /usr/include/c++/4.6/bits/stl_construct.h:104 #6 0x0807bd05 in std::_Destroy<boost::function<void ()>*>(boost::function<void ()>*, boost::function<void ()>*) (__first=0x858d938, __last=0x858d928) at /usr/include/c++/4.6/bits/stl_construct.h:127 #7 0x0807af23 in std::_Destroy<boost::function<void ()>*, boost::function<void ()> >(boost::function<void ()>*, boost::function<void ()>*, std::allocator<boost::function<void ()> >&) (__first=0x858d938, __last=0x858d928) at /usr/include/c++/4.6/bits/stl_construct.h:153 #8 0x0807a037 in std::deque<boost::function<void ()>, std::allocator<boost::function<void ()> > >::_M_destroy_data_aux(std::_Deque_iterator<boost::function<void ()>, boost::function<void ()>&, boost::function<void ()>*>, std::_Deque_iterator<boost::function<void ()>, boost::function<void ()>&, boost::function<void ()>*>) (this=0x858beec, __first=..., __last=...) at /usr/include/c++/4.6/bits/deque.tcc:795 #9 0x08076153 in std::deque<boost::function<void ()>, std::allocator<boost::function<void ()> > >::_M_destroy_data(std::_Deque_iterator<boost::function<void ()>, boost::function<void ()>&, boost::function<void ()>*>, std::_Deque_iterator<boost::function<void ()>, boost::function<void ()>&, boost::function<void ()>*>, std::allocator<boost::function<void ()> > const&) (this=0x858beec, __first=..., __last=...) at /usr/include/c++/4.6/bits/stl_deque.h:1816 #10 0x08073411 in std::deque<boost::function<void()>, std::allocator<boost::function<void()> > >::~deque(void) (this=0x858beec, __in_chrg=<optimized out>) at /usr/include/c++/4.6/bits/stl_deque.h:898 #11 0x0806a355 in std::queue<boost::function<void()>, std::deque<boost::function<void()>, std::allocator<boost::function<void()> > > >::~queue(void) (this=0x858beec, __in_chrg=<optimized out>) at /usr/include/c++/4.6/bits/stl_queue.h:92 #12 0x0815a054 in WorkerThreadManager::~WorkerThreadManager (this=0x858be98, __in_chrg=<optimized out>) at WorkerThreadManager.cpp:42 #13 0x0815a1e3 in WorkerThreadManager::~WorkerThreadManager (this=0x858be98, __in_chrg=<optimized out>) at WorkerThreadManager.cpp:56 #14 0x080c6c51 in std::auto_ptr<WorkerThreadManager>::reset (this=0x85463e4, __p=0x0) at /usr/include/c++/4.6/backward/auto_ptr.h:244 #15 0x080604a9 in main () Regards Marcin Adamski

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[ANN] ODB C++ ORM 2.1.0 released, adds support for Uuid, Multi-Index
by Boris Kolpackov 18 Sep '12

18 Sep '12

Hi, I am pleased to announce the release of ODB 2.1.0. ODB is an open source object-relational mapping (ORM) system for C++. It allows you to persist C++ objects to a relational database without having to deal with tables, columns, or SQL and without manually writing any of the mapping code. Major new features in this release: * Ability to use accessor/modifier functions and expressions to access data members. In most cases ODB is capable of discovering suitable accessor/modifier functions automatically. * Support for virtual (imaginary) data members that can be used to handle the C++ pimpl idiom as well as aggregate or dis-aggregate real data members. * Ability to define database indexes on data members. Multi-member indexes as well as indexes with database-specific index types, methods, and options are supported. * Support for mapping extended database types, such as geospatial types, user-defined types, collections (arrays, table types, etc.), key-value stores, XML, JSON, etc., to suitable C++ types. * The Boost profile library now provides persistence support for the Uuid and Multi-Index container libraries. * The Qt profile library now provides persistence support for the QUuid type. * Support for generating single (combined) database schema file from multiple C++ header files. This release also adds support for Visual Studio 2012 and Clang 3.1. Specifically, all the runtime libraries, examples, and tests now come with project/solution files for Visual Studio 2012 in addition to 2010 and 2008. A more detailed discussion of these features can be found in the following blog post: http://www.codesynthesis.com/~boris/blog/2012/09/18/odb-2-1-0-released/ For the complete list of new features in this version see the official release announcement: http://www.codesynthesis.com/pipermail/odb-announcements/2012/000018.html ODB is written in portable C++ and you should be able to use it with any modern C++ compiler. In particular, we have tested this release on GNU/Linux (x86/x86-64), Windows (x86/x86-64), Mac OS X, and Solaris (x86/x86-64/SPARC) with GNU g++ 4.2.x-4.7.x, MS Visual C++ 2008, 2010, and 2012, Sun Studio 12, and Clang 3.1. The currently supported database systems are MySQL, SQLite, PostgreSQL, Oracle, and SQL Server. ODB also provides profiles for Boost and Qt, which allow you to seamlessly use value types, containers, and smart pointers from these libraries in your persistent classes. More information, documentation, source code, and pre-compiled binaries are available from: http://www.codesynthesis.com/products/odb/ Enjoy, Boris

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[Review.Coroutine] Coroutine review comments
by Nat Linden 17 Sep '12

17 Sep '12

I like what I see so far, but I'm missing the coroutine future API. We use Giovanni Deretta's Summer of Code Coroutine prototype in production code, and we rely on his 'future' semantics. My intention was to test Oliver's Coroutine proposal by replacing it into our code, but this is not possible without something equivalent to 'future'. Accordingly, this review is based on the library documentation rather than on actual usage. (One could imagine passing a coroutine object itself as a callback for some other library, then calling yield() to await that callback. There are two obstacles. One is that I know of no way to obtain, within the coroutine-function, a reference to the containing coroutine object. The initial 'self' parameter is not that object; it presents a different API. A more serious problem is that the value returned by yield() is fixed by the coroutine template's Signature parameter. With futures, each future object can return a different type; a given coroutine can instantiate an arbitrary number of future objects with an arbitrary number of types to await an arbitrary sequence of callbacks.) > Please always state in your review, whether you think the library should be > accepted as a Boost library! I vote: conditionally accept. I cannot switch to this library without 'future' support. > Additionally please consider giving feedback on the following general > topics: > > - What is your evaluation of the design? Good > - What is your evaluation of the implementation? Did not review > - What is your evaluation of the documentation? Generally good; detailed suggestions follow > - What is your evaluation of the potential usefulness of the library? HIGH. More people need this functionality than realize it. :-) > - Did you try to use the library? With what compiler? Did you have any > problems? I did not > - How much effort did you put into your evaluation? A glance? A quick > reading? In-depth study? I read the documentation at the cited link: http://ok73.ok.funpic.de/boost/libs/coroutine/doc/html/ > - Are you knowledgeable about the problem domain? Yes ======================================================================== Detailed comments on documentation: First example in section "Coroutine": "boost::coro::coroutine< void() > c( make_coroutine() );" This example might benefit from a couple comments explaining its purpose. As the first example in the documentation, I thought it might illustrate a short but complete use case. It's only intended to demonstrate a coroutine object being returned by value from a function; but when I first read it I thought make_coroutine() was part of the library API, like make_shared(). "The coroutine-function, as well as its arguments, if any, are copied into the coroutine's state. If a reference is required, use boost::ref." Excellent! This is an important point. "The maximum number of arguments of coroutine-function is 10." Is that limit adjustable with a #define symbol? If not, it should be. Second example under "Executing a coroutine": coro_t c( boost::bind( fn, _1, 7) ); std::cout << "main() starts coroutine c" << std::endl; // yield was called so we returned ^ This comment, at this point in the code, perplexed me. while ( ! ctx.is_complete() ) ^ 'ctx' undefined, I think you mean coro_t 'c' { std::cout << "main() calls coroutine c" << std::endl; // execution control is transfered to c c(); // yield() was called within fn() } "In contrast to threads, which are preemtive, coroutine switches are cooperative (programmer controls when a switch will happen). The kernel is not involved in the coroutine switches." s/preemtive/preemptive/ I would love it if, somewhere in the introductory material, the library documentation emphasized the pragmatic benefit of cooperative switching: it requires no new defensive locking. s/allways/always/ "The arguments passed to coroutine<>::operator()(), in one coroutine, is returned by coroutine<>::self_t::yield() in the other coroutine..." At first glance this makes the reader wonder how yield() can possibly return up to 10 coroutine arguments. May I suggest: "...is returned (as a boost::tuple) by..." ? Example under "coroutine-function with multiple arguments": "boost::tuple< int, int > ret = self.yield( tmp);" This describes exactly the type returned, so is correct. Even so, I find myself thinking that a dubious reader might be more favorably impressed by an example using a couple scalar variables with boost::tie(). And it might clarify the example to use different types for the coroutine parameters. Example under "Exit a coroutine-function": s/self.yield_return()/self.yield_break()/ "An exception thrown inside coroutine-function (transfered via exception-pointer - see Boost.Exception for details and requirements) will be re-thrown by coroutine<>::operator()()." I'm not familiar with Boost.Exception. Will any exception be re-thrown, including exceptions raised by the runtime? Or does this only apply to exceptions derived from a particular base class, or thrown in a particular way? If there are such limitations, mentioning them briefly here would be extremely useful. "Code executed by coroutine must not prevent the propagation of the forced_unwind exception. Absorbing that exception will cause stack unwinding to fail. Thus, any code that catches all exceptions must rethrow the pending exception." This and the example should clarify that we're talking about code within the coroutine-function. (And is forced_unwind also within the boost::coro namespace?) If forced_unwind is the exception thrown when a (! is_complete()) coroutine object is destroyed, that's worth mentioning. It's possible that a coroutine-function might want to perform cleanup specific to that case. coroutine::self_t reference: "T yield( R);" T and R undefined. "template< typename Fn > coroutine( Fn fn, std::size_t size = ctx::default_stacksize(), flag_unwind_t do_unwind = stack_unwind, bool preserve_fpu = true, Allocator alloc = Allocator() );" flag_unwind_t undefined. "R operator()(A0 a0, ..., A9 a9);" R, A0, ... A9 undefined. Example in section "Generator": Undefined make_generator() function wants a comment. Again, this is a hypothetical user function rather than part of the boost::coro::generator API. "The first argument of generator-function must be of type generator<>::self_t, ..." The "only" argument? I'd like to see some words when generator is first introduced clarifying the ways in which it differs from coroutine. This what I think: * A generator-function accepts no arguments (other than self_t), so yield() always returns void. * yield_break() does not throw an exception in the invoking coroutine. * Anything else? It might be worth a few words to clarify that when you pass a boost::bind() expression, *that* is the generator-function, and it must accept only self_t. Any other parameters bound by boost::bind() are irrelevant to boost::coro::generator. In that connection, the function f() in the first "Executing a generator" example should probably accept a different parameter type than int so the reader can clearly distinguish between the type accepted by f() and the type passed to yield(). And in *that* connection, the self.yield() call in that example should pass an int value. "The generator-function, as well as its arguments, if any, are copied into the generator's state." Um, what arguments? Again, if you're using boost::bind() to adapt a function that accepts anything more than self_t, processing of additional arguments is up to boost::bind() -- not boost::coro::generator. "The maximum number of arguments of generator-function is 10." What does this mean? "generator-function is invoked the first time inside the constructor of generator." That makes no sense to me. Is the value passed to the first yield() call simply discarded? If so, why? "If generator-function can not return valid values anymore generator<>::self_t::yield_break() should be called. This function returns the execution control back to the caller and sets the generator to be complete (is_complete() returns true)." is_complete() is not documented for boost::coro::generator. "Of curse the generator-function can be exited with a return expression." s/curse/course/ Is there any semantic difference between executing 'return' in a generator-function and calling yield_break() in a generator-function? If not, is yield_break() provided only for consistency with coroutine? If a generator-function has a declared return type, is that value discarded? Example in "Exit a generator-function": "self_yield( i);" should be self.yield(i); "self.yield_return();" should be self.yield_break(); class generator::self_t reference: "void yield( R);" Is R the same as Result here? "Result operator()() Preconditions: *this is not a not-a-generator, ! is_complete()." is_complete() is not documented for boost::coro::generator. "void self_t::yield( Result) Effects: Gives execution control back to calling context by returning a value of type Result. The return type of this function is a boost::tuple<> containing the arguments passed to generator<>::operator()()." That entire last sentence seems untrue. "void self_t::yield_break() Effects: Gives execution control back to calling context and sets the generator to be complete. generator<>::operator()() in the other generator throws exception coroutine_terminated." Last sentence above contradicts other generator documentation.

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If *boost::filesystem::path::iterator was mutable it would be considerably more user friendly
by Sebastian Karlsson 17 Sep '12

17 Sep '12

Why is *boost::filesystem::path::iterator immutable? If it wasn't transformation of paths would be very user friendly, and we'd be able to leverage all the niceties which already works with iterators. As it is one has to create a ton of temporaries, and common operations which should be one liners becomes a mess. Kind regards, Sebastian Karlsson

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[Review:Contract] Boost.Contract Library is Accepted
by Dave Abrahams 17 Sep '12

17 Sep '12

Lorenzo Caminiti's Boost.Contract Library is hereby accepted into Boost. I will be brief but that should in no way be construed as a lack of enthusiasm. Reviewing the review commentary was a genuine pleasure. Anyone interested in this domain could learn a lot by going through the threads the way I did. There were five "yes" votes, one of which was very late (but I'm counting it), and one of which was conditional, and one "no" vote. I am accepting the library unconditionally because of Lorenzo's demonstrated responsiveness to issues. He gave thoughtful responses to the review comments and entered every issue raised that remained open into a bug database (http://sourceforge.net/apps/trac/contractpp/report/3) Congratulations, Lorenzo! -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

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[boost] [contract] static_assert in contracts or not?
by Lorenzo Caminiti 17 Sep '12

17 Sep '12

Hello all, If static assertions make sense within contracts (preconditions, postconditions, and class invariants) is a questions that has been raised by both Vicente and Andrzej. I don't have a definitive answer so I'd like to discuss with the ML. On Wed, Aug 29, 2012 at 2:48 PM, Andrzej Krzemienski <akrzemi1(a)gmail.com> wrote: > (6) > Static assertions: is there any value in providing them, given that we > already have this ability in Boost? I see that N1962 decided to abandon > them; I am pretty sure the reason was that static_assert was already there. > They somehow do not fit conceptually into the model of preconditions, > postconditions and invariants. Precondition, for instance tries to detect a > run-time condition occurring immediately before a function is called this > time. Static assertion is not even executed then. What point is there in > putting such assertion into the precondition? Documentation says " static > assertions can be selectively disabled depending on where they are > specified [...] so it is still important to logically associate them with > preconditions, postconditions, etc." -- technically this sentence makes > logical sense, but can you think of a single example where this selective > disabling of assertions would be useful? What is the point in disabling > such assertions at all, if they cost you nothing in run-time? I propose to > remove them and give a sort of recommendation that software quality is > assured by using a number of fairly independent tools: DbC, concepts, > static assertions. I think we can break down the question in two parts. Let's assume N1962 is accepted into C++1x so we have both contracts and static_assert. 1) Would you expect to be able to use static_assert within contract assertions (preconditions, postconditions, and class invariants)? Note that only boolean conditions are allowed by N1962 within contracts, general code is not allowed, therefore this is not a trivial question. For example, would you expect to be able to do the following option A: template< typename To, typename From > To* memcopy ( To* to, From* from ) precondition{ static_assert(sizeof(To) >= sizeof(From), "destination too small"); static_assert(boost::is_convertible<From, To>::value, "incompatible types"); to; // pointer not null from; // pointer not null } { // ... } In this case, would it ever make sense to use static_assert in postcondition and/or class invariants even if that were allowed? Or would you just use static_assert in the body, option B: template< typename To, typename From > To* memcopy ( To* to, From* from ) precondition{ to; // pointer not null from; // pointer not null } { static_assert(sizeof(To) >= sizeof(From), "destination too small"); static_assert(boost::is_convertible<From, To>::value, "incompatible types"); // ... } I don't like this because the assertions are about the specifications (they assert a requirement of the interface) so they should go in the declaration and not in the implementation. Or maybe the assertions should be represented as concept requirements on To and From, option C: template< typename To, typename From > requires SizeofGreaterEqual<To, From>, Convertible<From, To> To* memcopy ( To* to, From* from ) precondition{ to; // pointer not null from; // pointer not null } { // ... } (Only we don't have concepts...) 2) Let's assume, we answered option A to question 1): template< typename To, typename From > To* memcopy ( To* to, From* from ) precondition{ static_assert(sizeof(To) >= sizeof(From), "destination too small"); static_assert(boost::is_convertible<From, To>::value, "incompatible types"); to; // pointer not null from; // pointer not null } { // ... } Would you expect these static_asserts to be disabled when precondition compilation and checking is turned off at compilation time? I'd think so. Thanks. --Lorenzo

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Using Boost.Process on Windows
by Ronan Trépos 15 Sep '12

15 Sep '12

Hello, I'm trying to compile start_child example of Boost.Process with this configuration: Windows 64 bits MinGW g++ 4.6.2 boost_1-51 Boost.Process 0.5 And I have this error: error: no matching function for call to 'boost::system::system_error::system_error(DWORD, const boost::system::error_category& (&)(), const char [54])' note: candidates are: boost::system::system_error::system_error(int, const boost::system::error_category&, const char*) ... This difficulty was mentioned on the list "[Boost-users] [Process] Can't build example" at date 12/4/10. Am i missing something ? Thank you in advance Best regard Ronan Trépos -- Trépos Ronan INRA unité BIA, équipe MAD, Toulouse http://carlit.toulouse.inra.fr/wikiz/index.php/Ronan_TREPOS tel : 05 61 28 51 89

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How to compile static library with -fPIC from boost.python
by simon zhang 15 Sep '12

15 Sep '12

Hi all Default,libboostpython.a has be compiled without -fPIC.But I have to make a python extending and it is a dynamic library with -fPIC that link to static library. How to compile static library (libboostpython.a) with -fPIC from boost.python simon

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std::set_intersection without results
by Jens Müller 14 Sep '12

14 Sep '12

Hi everyone, I'm trying to test whether two std::vector's intersect. A straightforward way is to sort them, apply std::set_intersection and test whether the result set is non-empty. However, I don't need the result. Is there some algorithm in boost that just _tests_ for intersection, i.e., stops when it has found one common element? Best regards, Jens

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[filesystem] boost::filesystem::current_path: No such file or directory
by Frédéric Bron 14 Sep '12

14 Sep '12

Hi, sometimes, when I run my program, I get that exception: terminate called after throwing an instance of 'boost::filesystem3::filesystem_error' what(): boost::filesystem::current_path: No such file or directory Aborted What could be the cause for this? I am using 1.49.0 on linux x86_64 compiled with g++ 4.6.2. Regards, Frédéric

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[lambda] Using a reference in an expression
by Bill Buklis 13 Sep '12

13 Sep '12

How does one use a reference in a lambda expression? The documentation says that "var" does, but it clearly doesn't. For example this fails to compile because it can't access the copy constructor: #include <boost/lambda.hpp> namespace bll = boost::lambda; class sample { public: sample() { } sample& operator<<( int ) { return(*this); } private: sample( const sample& ); }; void test() { typedef std::vector<int> V; V v; sample s; std::for_each(v.begin(), v.end(), bll::var(s) << bll::_1); }; -- Bill

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[scope exit] docs broken in 1.50
by Ovanes Markarian 13 Sep '12

13 Sep '12

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Install boost on OS X via homebrew with c++11 and libc++
by christoffer.buchholz＠gmail.com 13 Sep '12

13 Sep '12

I'm trying to install boost on OS X with c++11 and libc++. I'm using homebrew (boost formular with the --build-from-source argument) and have tried various options with adding stuff like * toolset=clang * cxxflags="-stdlib=libc++ -std=c++11" * cxxflags="-stdlib=libc++" * linkflags="-stdlib=libc++ -std=c++11" * linkflags="-stdlib=libc++" as arguments to bjam, but it all fails. Now... The "toolset" part doesn't do anything to make it fail though, its the cxx- and linkflags part that does. This is what I get when it fails clang-darwin.archive bin.v2/libs/exception/build/clang-darwin-4.2.1/release/link- static/threading-multi/libboost_exception-mt.a common.copy /usr/local/Cellar/boost/1.50.0/lib/libboost_exception-mt.a clang-darwin.compile.c++ bin.v2/libs/wave/build/clang-darwin-4.2.1/release/link- static/threading-multi/cpplexer/re2clex/cpp_re.o clang-darwin.archive bin.v2/libs/wave/build/clang-darwin-4.2.1/release/link-static/threading-multi/libboost_wave-mt.a common.copy /usr/local/Cellar/boost/1.50.0/lib/libboost_wave-mt.a ...failed updating 2 targets... ...skipped 4 targets... ...updated 10592 targets... Error: #<BuildError: Failed executing: ./bjam toolset=clang cxxflags="-stdlib=libc++" linkflags="-stdlib=libc++" --prefix=/usr/local/Cellar/boost/1.50.0 -- libdir=/usr/local/Cellar/boost/1.50.0/lib -j2 --layout=tagged --user-config=user-config.jam threading=multi install> How do I get boost installed on OS X Mountain Lion with c++11 and libc++ preferably via homebrew for the ease it adds. Sincerely, Christoffer Buchholz

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[test] BOOST_CHECK_EQUAL comparisons with NULL don't compile
by James Mathiesen 13 Sep '12

13 Sep '12

This use case seems really common and I was surprised it gave me problems. I assume that nullptr_t in C++11 fixes this but then I was wondering if the cases were basic and common enough it would make sense to have a BOOST_CHECK_NULL / BOOST_CHECK_NOT_NULL and the assorted variants. james --- #define BOOST_TEST_DYN_LINK #define BOOST_TEST_MODULE Hello #include <boost/test/unit_test.hpp> // main() etc... is defined by the headers BOOST_AUTO_TEST_CASE( null_compare ) { const char *ptr = NULL; // // Equality comparisons with NULL Fail to compile using boost 1.46 // and g++-4.6 // // /usr/include/boost/test/test_tools.hpp:536:20: // error: ISO C++ forbids comparison between pointer and // integer [-fpermissive] // // Which seems to be flagging this // // template <class Left, class Right> // predicate_result equal_impl( Left const& left, Right const& right ) // { // return left == right; // } // // Where Left is of type "const char *" and Right is of type "long int". // BOOST_CHECK_EQUAL(ptr, NULL); // // these tests compile and pass // BOOST_CHECK(ptr == NULL); BOOST_CHECK_EQUAL(ptr, ptr); BOOST_CHECK_EQUAL(ptr, (void *)ptr); BOOST_CHECK_EQUAL(ptr, (void *)NULL); } ... example.cc:33:1: error: passing NULL to non-pointer argument 9 of ‘bool boost::test_tools::tt_detail::check_frwd(Pred, const boost::unit_test::lazy_ostream&, boost::test_tools::const_string, std::size_t, boost::test_tools::tt_detail::tool_level, boost::test_tools::tt_detail::check_type, const Arg0&, const char*, const Arg1&, const char*) [with Pred = boost::test_tools::tt_detail::equal_impl_frwd, Arg0 = const char*, Arg1 = long int, boost::test_tools::const_string = boost::unit_test::basic_cstring<const char>, std::size_t = long unsigned int]’ [-Werror=conversion-null] example.cc:33:1: error: passing NULL to non-pointer argument 9 of ‘bool boost::test_tools::tt_detail::check_frwd(Pred, const boost::unit_test::lazy_ostream&, boost::test_tools::const_string, std::size_t, boost::test_tools::tt_detail::tool_level, boost::test_tools::tt_detail::check_type, const Arg0&, const char*, const Arg1&, const char*) [with Pred = boost::test_tools::tt_detail::equal_impl_frwd, Arg0 = const char*, Arg1 = long int, boost::test_tools::const_string = boost::unit_test::basic_cstring<const char>, std::size_t = long unsigned int]’ [-Werror=conversion-null] In file included from /usr/include/boost/test/unit_test.hpp:19:0, from example.cc:7: /usr/include/boost/test/test_tools.hpp: In function ‘boost::test_tools::predicate_result boost::test_tools::tt_detail::equal_impl(const Left&, const Right&) [with Left = const char*, Right = long int]’: /usr/include/boost/test/test_tools.hpp:560:40: instantiated from ‘boost::test_tools::predicate_result boost::test_tools::tt_detail::equal_impl_frwd::call_impl(const Left&, const Right&, mpl_::false_) const [with Left = const char*, Right = long int, mpl_::false_ = mpl_::bool_<false>]’ /usr/include/boost/test/test_tools.hpp:575:56: instantiated from ‘boost::test_tools::predicate_result boost::test_tools::tt_detail::equal_impl_frwd::operator()(const Left&, const Right&) const [with Left = const char*, Right = long int]’ /usr/include/boost/test/test_tools.hpp:523:1: instantiated from ‘bool boost::test_tools::tt_detail::check_frwd(Pred, const boost::unit_test::lazy_ostream&, boost::test_tools::const_string, std::size_t, boost::test_tools::tt_detail::tool_level, boost::test_tools::tt_detail::check_type, const Arg0&, const char*, const Arg1&, const char*) [with Pred = boost::test_tools::tt_detail::equal_impl_frwd, Arg0 = const char*, Arg1 = long int, boost::test_tools::const_string = boost::unit_test::basic_cstring<const char>, std::size_t = long unsigned int]’ example.cc:33:1: instantiated from here /usr/include/boost/test/test_tools.hpp:536:20: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]

4 3

boost 1.47.0 installation
by Usman Dastgeer 13 Sep '12

13 Sep '12

Hello, I am trying to install boost for the first time as part of rose compiler installation. Here is what I did on a Linux machine: downloaded, extracted boost 1.47.0 ./bootstrap.sh --prefix=/home/usmda/rose/ boost/install2 --with-python-version=2.7 ./bjam install -sGCC=gcc-4.4 -sGXX=g++-4.4 --prefix=/home/usmda/rose/boost/install2 Default gcc version is 4.7.1 [/usr/bin/g(cc|++)] on this machine so I specify the gcc 4.4 [/usr/bin/g(cc|++)-4.4] for 2 reasons: 1) I need to use gcc 4.4 to compile rose compiler as well. 2) I read that gcc 4.7.1 disables boost threading support so that's why I want to use gcc 4.4 but specifying -sGCC and -sGXX didn't help as still I guess it uses gcc-4.7.1 (as shown in log below).* * Build fail for 4 targets. Here is the build message... ... In file included from ./boost/thread/detail/platform.hpp:17:0, from ./boost/thread/detail/config.hpp:20, from libs/thread/src/pthread/thread.cpp:8: ./boost/config/requires_threads.hpp:29:4: error: #error "Threading support unavaliable: it has been explicitly disabled with BOOST_DISABLE_THREADS" In file included from ./boost/thread/pthread/mutex.hpp:14:0, from ./boost/thread/mutex.hpp:16, from ./boost/thread/pthread/thread_data.hpp:12, from ./boost/thread/thread.hpp:17, from libs/thread/src/pthread/thread.cpp:10: ./boost/thread/xtime.hpp:23:5: error: expected identifier before numeric constant ./boost/thread/xtime.hpp:23:5: error: expected ‘}’ before numeric constant ./boost/thread/xtime.hpp:23:5: error: expected unqualified-id before numeric constant ./boost/thread/xtime.hpp:46:14: error: expected type-specifier before ‘system_time’ In file included from ./boost/thread/pthread/mutex.hpp:14:0, from ./boost/thread/mutex.hpp:16, from ./boost/thread/pthread/thread_data.hpp:12, from ./boost/thread/thread.hpp:17, from libs/thread/src/pthread/thread.cpp:10: ./boost/thread/xtime.hpp: In function ‘int xtime_get(xtime*, int)’: ./boost/thread/xtime.hpp:73:40: error: ‘get_system_time’ was not declared in this scope ./boost/thread/xtime.hpp:73:40: note: suggested alternative: In file included from ./boost/thread/locks.hpp:12:0, from ./boost/thread/pthread/mutex.hpp:12, from ./boost/thread/mutex.hpp:16, from ./boost/thread/pthread/thread_data.hpp:12, from ./boost/thread/thread.hpp:17, from libs/thread/src/pthread/thread.cpp:10: ./boost/thread/thread_time.hpp:19:24: note: ‘boost::get_system_time’ In file included from ./boost/thread/pthread/mutex.hpp:14:0, from ./boost/thread/mutex.hpp:16, from ./boost/thread/pthread/thread_data.hpp:12, from ./boost/thread/thread.hpp:17, from libs/thread/src/pthread/thread.cpp:10: ./boost/thread/xtime.hpp: At global scope: ./boost/thread/xtime.hpp:88:1: error: expected declaration before ‘}’ token "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -Wno-long-long -DBOOST_ALL_NO_LIB=1 -DBOOST_THREAD_BUILD_LIB=1 -DBOOST_THREAD_POSIX -DNDEBUG -I"." -c -o "bin.v2/libs/thread/build/gcc-4.7.1/release/link-static/threading-multi/pthread/thread.o" "libs/thread/src/pthread/thread.cpp" ...failed gcc.compile.c++ bin.v2/libs/thread/build/gcc-4.7.1/release/link-static/threading-multi/pthread/thread.o... gcc.compile.c++ bin.v2/libs/thread/build/gcc-4.7.1/release/link-static/threading-multi/pthread/once.o In file included from ./boost/thread/detail/platform.hpp:17:0, from ./boost/thread/once.hpp:12, from libs/thread/src/pthread/once.cpp:7: ./boost/config/requires_threads.hpp:29:4: error: #error "Threading support unavaliable: it has been explicitly disabled with BOOST_DISABLE_THREADS" "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -Wno-long-long -DBOOST_ALL_NO_LIB=1 -DBOOST_THREAD_BUILD_LIB=1 -DBOOST_THREAD_POSIX -DNDEBUG -I"." -c -o "bin.v2/libs/thread/build/gcc-4.7.1/release/link-static/threading-multi/pthread/once.o" "libs/thread/src/pthread/once.cpp" ...failed gcc.compile.c++ bin.v2/libs/thread/build/gcc-4.7.1/release/link-static/threading-multi/pthread/once.o... ...skipped <pbin.v2/libs/thread/build/gcc-4.7.1/release/link-static/threading-multi>libboost_thread.a(clean) for lack of <pbin.v2/libs/thread/build/gcc-4.7.1/release/link-static/threading-multi>pthread/thread.o... ...skipped <pbin.v2/libs/thread/build/gcc-4.7.1/release/link-static/threading-multi>libboost_thread.a for lack of <pbin.v2/libs/thread/build/gcc-4.7.1/release/link-static/threading-multi>pthread/thread.o... ...skipped <p/home/usmda/rose/boost/install2/lib>libboost_thread.a for lack of <pbin.v2/libs/thread/build/gcc-4.7.1/release/link-static/threading-multi>libboost_thread.a... gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.7.1/release/link-static/threading-multi/instantiate_cpp_exprgrammar.o gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.7.1/release/link-static/threading-multi/instantiate_cpp_grammar.o gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.7.1/release/link-static/threading-multi/instantiate_cpp_literalgrs.o gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.7.1/release/link-static/threading-multi/instantiate_defined_grammar.o gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.7.1/release/link-static/threading-multi/instantiate_predef_macros.o gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.7.1/release/link-static/threading-multi/instantiate_re2c_lexer.o gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.7.1/release/link-static/threading-multi/instantiate_re2c_lexer_str.o gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.7.1/release/link-static/threading-multi/token_ids.o gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.7.1/release/link-static/threading-multi/wave_config_constant.o gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.7.1/release/link-static/threading-multi/cpplexer/re2clex/aq.o gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.7.1/release/link-static/threading-multi/cpplexer/re2clex/cpp_re.o gcc.archive bin.v2/libs/wave/build/gcc-4.7.1/release/link-static/threading-multi/libboost_wave.a common.copy /home/usmda/rose/boost/install2/lib/libboost_wave.a ...failed updating 4 targets... ...skipped 9 targets... ...updated 9270 targets...

2 1

[Interprocess] Growing resets permissions
by Aaron_Wright＠selinc.com 12 Sep '12

12 Sep '12

I have a situation where I don't know how much shared memory I need, so I made the shared memory grow when it ran out of space. My shared memory is shared between a process running as root and postgres, which won't run as root. So I set the permissions to unrestricted (0666) when I create the shared memory. My problem is that when I grow the shared memory, the permissions are reset to (0644). This breaks things, as postgres can no longer open the shared memory for writing. I followed the code a bit and saw that it was using ftruncate. Checking the man page for ftruncate reveals, "the set-user-ID and set-group-ID permission bits may be cleared." Has anyone else ran into this? What is the easy solution? Should I just set the permissions manually after growing? Is this a bug in the interprocess library? --- Aaron Wright

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FW: [Review] Coroutine review starts today, September 3rd, ends September 12th
by Hartmut Kaiser 11 Sep '12

11 Sep '12

This is just a reminder that the review of Oliver's Boost.Coroutine is ending tomorrow (see below for the initial announcement). Please get your reviews in as soon as possible. If you need more time, please let me know. Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu > -----Original Message----- > From: Hartmut Kaiser [mailto:hartmut.kaiser@gmail.com] > Sent: Monday, September 03, 2012 6:46 AM > To: boost-users(a)lists.boost.org > Subject: {Review] Coroutine reviewstarts today, September 3rd > > > Hi all, > > The review of Oliver Kowalke's Boost.Coroutine library starts today, > September 3rd 2012, and will end on September 12th. > I really hope to see your vote and your participation in the discussions > on the Boost mailing lists! > > ----------------------------------------------------- > > About the library: > > Boost.Coroutine provides templates for generalized subroutines > (coroutines) which allow multiple entry points for suspending and resuming > execution at certain locations. It preserves local state/data and allows > re-entering subroutines more than once (useful if state must be kept > across function calls). Coroutines can be viewed as a language-level > construct providing a special kind of control flow. > > You can download the library and the view documentation here: > > docs: http://ok73.ok.funpic.de/boost/libs/coroutine/doc/html/ > src: http://ok73.ok.funpic.de/boost.coroutine.zip > > --------------------------------------------------- > > Please always state in your review, whether you think the library should > be accepted as a Boost library! > > Additionally please consider giving feedback on the following general > topics: > > - What is your evaluation of the design? > - What is your evaluation of the implementation? > - What is your evaluation of the documentation? > - What is your evaluation of the potential usefulness of the library? > - Did you try to use the library? With what compiler? Did you have any > problems? > - How much effort did you put into your evaluation? A glance? A quick > reading? In-depth study? > - Are you knowledgeable about the problem domain? > > Regards Hartmut > Review Manager

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Fusion error: wrong number of template arguments (30, should be 20)
by Joost Kraaijeveld 11 Sep '12

11 Sep '12

Hi, I have the following error after an upgrade to Boost 1.49 (Debian Wheezy): /usr/include/boost/fusion/container/deque/detail/preprocessed/deque_initial_size30.hpp:14:196: error: wrong number of template arguments (30, should be 20) In file included from /usr/include/boost/mpl/aux_/include_preprocessed.hpp:37:0, from /usr/include/boost/mpl/vector.hpp:46, from /usr/include/boost/fusion/container/deque/detail/deque_initial_size.hpp:16, from /usr/include/boost/fusion/container/deque/deque.hpp:15, from /usr/include/boost/fusion/container/deque.hpp:11, from /usr/include/boost/fusion/container.hpp:14, from ../../../library/../include/Danu/DanuModelObjects/Login.hpp:12, from ../../../library/DanuModelObjects/Login.cpp:7: /usr/include/boost/mpl/aux_/preprocessed/gcc/vector.hpp:22:8: error: provided for 'template<class T0, class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10, class T11, class T12, class T13, class T14, class T15, class T16, class T17, class T18, class T19> struct boost::mpl::vector' I have defined the following: #define FUSION_MAX_VECTOR_SIZE 30 #define FUSION_MAX_MAP_SIZE 30 How can I solve this problem? TIA -- Groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 web: www.askesis.nl

3 7

[Range] insert algorithm fails if target is a map
by Robert Jones 11 Sep '12

11 Sep '12

The title says it all really. The failure occurs because the insert algorithm expects the container to provide a 3-arg insert of the form container.insert( position, begin, end ); whereas map's, multimap's and set's insert method only takes two arguments... map.insert( begin, end ); Is this limitation by design? It would be easy to provide specialisations for maps, mmaps and sets, but that would not be a completely general solution. - Rob.

3 3

Compilation error trying to pull in Boost::threads header file
by Sunil Matta 10 Sep '12

10 Sep '12

Error compiling a program trying to use Boost::thread. Nothing special on the offending line, simply an include of thread.hpp Fedora 17 gcc 4.7 Boost: 1_47_0 /usr/local/lib/Boost/boost_1_ 47_0/boost/thread/pthread/thread_data.hpp:36:41: error: use of deleted function ‘boost::shared_ptr<boost::detail::tss_cleanup_function>::shared_ptr(const boost::shared_ptr<boost::detail::tss_cleanup_function>&)’ 1) Seems like boost is trying to pull in boost:shared_ptr. Shouldnt this be pulling this from the std namespace now ? 2) Why are the boost libraries in a stage dir ? i.e. boost_1_47_0/*stage/* lib/libboost_program_options.so.1.47.0 Is this standard now ? tia, Sunil

3 3

[serialization] disable BOOST_STATIC_WARNING for track_never objects?
by Brian Budge 10 Sep '12

10 Sep '12

Hi all - It's possible that I'm still doing something questionable, in which case, I hope you'll let me know. If what I'm doing is okay, perhaps there's a way to disable this warning. I have a virtual class hierarchy which I use to pass messages via boost.mpi. These messages then perform dispatch through helper objects on either side of the communication. I want to turn off object pointer tracking, so I've set my classes via BOOST_CLASS_TRACKING(myclass, boost::serialization::track_never). I thought this would just turn it off without a hitch, but I get a huge cascade of warning/error messages stemming from check_pointer_tracking(), where there is a comment that "serializing an object of a type marked "track_never" through a pointer could result in creating more objects than were saved!". If this is expected, how can I turn the warning off? If it is not expected, are there suggestions for what might be changed? Thanks, Brian

2 2

boost program options with ublas vector
by Kraus Philipp 10 Sep '12

10 Sep '12

Hello, I try to read a boost::ublas::vector with the boost::program_options and I get an error "abort trap". My call shows ("init", po::value< ublas::vector<double> >()->multitoken(), "Initialization") With a std::vector everything works fine. po is a shortcut to boost::program_option and ublas to boost::ublas How / can I use a ublas vector with a multitoken on the program options? Thanks Phil

1 0