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[filesystem] Linux copy_file api with wpath
by Joshua Peterson 26 Aug '08

26 Aug '08

It seems that Boost.FileSystem does not implement some methods accepting wpath arguments when compiled with GCC 3.4.3 on Linux. This occurs because BOOST_FILESYSTEM_NARROW_ONLY is defined, which according to the comment in the code occurs for "badly broken compilers or libraries". Ideally, I would like to use the boost::filesystem::copy_file() method on both Windows and Linux, passing wpath arguments in both cases. Is the lack of wpath support simply a problem with GCC 3.4.3, or is wpath never supported for copy_file() with GCC? I can see from the implementation of boost::filesystem::detail::copy_file_api() that open(), read(), and write() are used to copy the file. Since open() accepts only a const char* this may be the limitation. If this is the case, has there been any discussion of providing a copy_file() method which accepts wpath arguments and converts from wchar_t to char before calling copy_file_api(). I do not have a lot of experience with locales and character encodings, so I may be missing something. If this has already been discussed on this mailing list or elsewhere, please point me to the correct discussion, as I have been unable to find it. Thanks. Josh -- Rejoice always. Pray without ceasing. In all circumstances give thanks, for this is the will of God for you in Christ Jesus. -- 1 Thes. 5:16-18 NAB -- I am the living bread that came down from heaven; whoever eats this bread will live forever; and the bread that I will give is my flesh for the life of the world. -- John 6:51 NAB

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[function_types] member_ccs / GCC test annotations
by David Abrahams 25 Aug '08

25 Aug '08

With x86 linux gcc-4.0.1, I get this for the member_ccs test: member_ccs.cpp:17:5: error: #error "test not supported with this compiler/platform" and the test is annotated thusly: Not all compilers/platforms implement nonstandard calling conventions. With GCC/x86 this failure reflects http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29328 . But the nonme the nonmember_ccs test *also* fails with the same error, and this annotation: Not all compilers/platforms implement nonstandard calling conventions. i.e. there is no reference to a GCC bug. Points: * The error message for member_ccs is inconsistent with the note about the gcc bug. * The function types library documentation barely mentions "calling conventions" and doesn't explain what "nonstandard" means in this context. For example, does extern "C" count? * Since I am running x86/GCC, the note about the GCC bug much more specific than the other part of the note, so I assumed that it applied. That would mean that my platform implements a nonstandard calling convention, but a compiler bug is causing the test to fail. * However, that interpretation would be inconsistent with the annotation for nonmember_ccs. * I suspect that my platform does not support nonstandard calling convention, and the bug only applies on platforms where GCC supports nonstandard calling conventions (e.g. Windows), and does not apply to me. If so, the annotation should be more specific about the platforms on which the note applies. * The error message should be better, e.g.: "this platform does not support nonstandard calling conventions; the test is irrelevant here" * A test that always succeeds when the platform doesn't support nonstandard calling conventions would yield far more reliable results than the overly general wildcard matching of failure annotations you have now, which makes a failure on any platform look as though it were expected in the testing chart. -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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Problems with boost 1.36 and serialization library with VS2005 SP1
by Hansi 25 Aug '08

25 Aug '08

Hello, at the moment I wont to switch from boost 1.34.1 to 1.36. But now I have a compile error witch depends from the serialization error. I have a managed application and for that there is also a definition array in the cli namespace. The new version of boost seems to define somewhere the namespace boost globally and so it is not anymore possilbe to compile the application. I have searched where this problem exists but I don't have found the header... I have found only that the problem exists when this 2 headeres are included #include <boost/serialization/detail/shared_ptr_132.hpp> #include <boost/archive/basic_binary_iprimitive.hpp> Has anyone an idea how I can solve the problem? Best regards Hansjörg

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Cannot compile the debug version.
by john chen 25 Aug '08

25 Aug '08

Dear All, I wouldn't be able to compile the debug version of boost_1.360 (cannot find *-gd* under boost/lib). I tried following bjam arguments: bjam ^ --prefix=c:\boost install ^ --build-dir=c:\boost ^ --sBUILD=debug ^ --toolset=msvc ^ --threading=multi ^ --link=static and bjam ^ --prefix=c:\boost install ^ --build-dir=c:\boost ^ --sBUILD=debug release ^ --toolset=msvc ^ and it still doesn't build the debug version. My environment: ms vista 32 ms vc9 sp1 boost 1.360 bjam 03.1.17 Can someone tell me how to get the debug version? Thanks very much. John

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[math][libs] Header-only status wrong for Boost.Math
by Daryle Walker 25 Aug '08

25 Aug '08

Looking at <http://www.boost.org/doc/libs>, I see 14 entries using separate source, but I have 15 source directories still in my all- Boost library project. It seems that the Special Function section of the Math library has separate source for the (optional) C99 and TR1 math functions, but the library page doesn't list that. (The source files are mentioned in the Math-SpecFunc docs.) Can that be changed, please? -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com

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[test] More on formatting log entries for XCode (by default when applicable)
by Daryle Walker 25 Aug '08

25 Aug '08

This is based on the <https://svn.boost.org/trac/boost/ticket/2059> ticket I entered a couple months ago. I just tried out the actual change needed and attached it to the ticket. (I just made a project that compiles all the mandatory Boost source code, like the unit-test framework, into various static libraries I can include in my other projects without repeating the compilation instructions [or wasting disk space]. Centralization is fun.) I still don't know if my __APPLE_CC__ preprocessor test is the official way to check for Xcode, or any compatible, setup. I heard that the current code is supposedly formatted for Visual C++'s error message handling. If so, and the class I changed is _not_ where the per-compiler-product changes are supposed to go, then move the code as needed. (I guess there would be parallel visual-c++ and xcode default formatting classes.) -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com

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Re: [boost] New libraries should provide forward declarations? (Benoit))
by rtsweng-sw＠yahoo.com 25 Aug '08

25 Aug '08

>>>That would make it possible to easily separate the compilation of >>>boost classes (or at least their methods) from that of user-defined >>>classes. >> No, unfortunately, it wouldn't, because you have to pull in the >> definitions to use the template class, what you want is precompiled >> headers. >This is not exactly true. I already use such an approach in my own >developments. >The idea is to use concepts to make sure that the right member >functions are called inside a cpp file and therefore will be compiled >and usable everywhere.That would mean pulling in all related >implementation details... But only for one compilation unit (created >with that purpose in mind). Other compilation units would only have >access to template class definitions. For that matter, i personally >use the .h extension for template class definitions and .hpp for >template class method definitions (but that's only an example of what >could be done). >Note that i agree that it would also bring a readability benefit to >the source code. >BenoÃ®t This sounds exactly like what I am trying to do, I already split the declarations into .h files and the definitions into .hpp. Can you give a brief example of using a single .cpp file for compilation? Is this done like MSVC stdafx files? Thanks, Robert ________________________________

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[Release] Supported platforms are...?
by Gennaro Prota 24 Aug '08

24 Aug '08

In <http://www.boost.org/development/tests/release/developer/summary.html> I just see seven platform/compiler combinations. Are these the only ones officially supported for release(s)? -- Genny

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Lag of trunk tests?
by Gennaro Prota 24 Aug '08

24 Aug '08

I'm watching the trunk regression summary for several days and almost all the tests are reportedly stale at 19-21 August. If I go, for instance, to <http://www.boost.org/development/tests/trunk/Sandia-sun.html> it says that tests are run *nightly* (incidentally, it also doesn't tell anything about the gcc invocation). What's wrong? -- Genny

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[FileSystem.path] has_branch_path() not found
by Ming 24 Aug '08

24 Aug '08

Hi all, I try to use boost 1.36 instead of 1.33 to compile libtorrent library. But I got a error of "error C2039: 'has_branch_path' : is not a member of 'boost::filesystem::basic_path<String,Traits>' " I cannot find the function in boost\filesystem\path.hpp in version 1.36, but can find in in 1.33. Does has_branch_path() is deprecated in the new version library? Or it is moved to other classes? Yours, CMing

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[C++-sig][BGL] python bindings for intel compiler
by Sandeep Gupta 24 Aug '08

24 Aug '08

Hi, I haven't been able to create correct python bindings for BGL for intel compiler. Will greatly appreciate any help as it has been more than four months since I first encountered the problem. The python bindings in the tutorial and examples work fine. The bgl_python code from the sandbox compiles smoothly. I believe I have set the PYTHONPATH and LD_LIBRARY_PATH correctly. But the import of boost.graph fails with following error: Traceback (most recent call last): File "<stdin>", line 1, in <module> File "...../bgl-python/lib/python/boost/graph/__init__.py", line 16, in <module> from boost.graph._graph import * ImportError: "...../bgl-python/lib/python/boost/graph/_graph.so: undefined symbol: _ZN5boost5graph6python11basic_graphINS_11undirectedSEED1Ev" Thanks, Sandeep

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Trying to make an all-Boost header/library
by Daryle Walker 24 Aug '08

24 Aug '08

I started out making a group Boost project for Xcode, so I can compile Boost.Test and S11N just once and include them in my other projects. Then I wondered how far can I take this. 1. I tried including all the sources in the libs/ directory. 2. It seems that there is source code in the detail, function-types, and smart_ptr that we don't really need, so I've now excluded it. (The function-types one needed the Wave _tool_ to be created, so I really hope it's not needed.) 3. Just like Linux has various package installers (apt-get, etc.), so does Mac OS X. I originally had Fink, but switched to MacPorts. Dowloaded packages include: bzip2, docbook, doxygen, expat, fop, ghostscript, graphviz, icu, libxml1, openmpi, subversion, texlive, and zlib. 4. I generally have one static library file for each Boost library. For libraries that need another, I made the corresponding targets dependencies, but I didn't link the results together. 5. The test library gets three static libraries. They all include a "main" or something like it, so I'll probably make a custom fourth library for a grand Boost library file. 6. The graph library has extra support for Expat, which I included from MacPorts. Should I leave that out for a publicly distributed grand Boost library file, since I can't guarantee a general user having it? 7. The iostreams library has extra support for bzip2 and zlib, which I originally included from MacPorts. I realized that my system (Mac OS X 10.4, PowerPC) includes copies of those libraries and headers, so I switched to those. This means that I can safely include them in a grand Boost library, right? 8. I left out the long-double versions of the math functions because they're disabled on my system. Should I try (conditionally?) including them on Intel-builds since I think they're supported there? How do I do that? 9. I have the MPI library built because I have OpenMPI through MacPorts. Should I leave that out of a grand Boost library? 10. For the Python library, I tried connecting to the OS's Python.framework. 11. Because of [9] and [10], I made the MPI-Python library too. I guess its status for a grand Boost library depends on the answer for [9]. 12. Does anyone have any idea how to create a Python extension? I did a very quick read of the docs and couldn't get it. So I just made a shared library for the MPI extension for Python and included the applicable static libraries and framework. (It seems you are supposed to use a special Python script, and _never_ manually.) Since I made a final product, I had to link in my static libraries for MPI, Python, MPI-Python, and S11N, then link the OpenMPI libraries from MacPorts, then the system's Python framework, then a surprise need for some Open libraries also from MacPorts. 13. For the regex library, I defined having ICU, and included it from MacPorts. Should I leave out ICU support in a grand Boost library? Actually, I think the system has buried copies of Expat and ICU, but I don't know how to reach them, or if it's even possible. Maybe I should try making a framework of all of Boost, modulo the answers on what I should include above. Should I somehow include object-code for the parts of the Test library that bring a "main"? Or do I have to tell the user to get the framework, then download regular Boost to build what's needed for Testing (or MPI, MPI/Python, Graph/Expat, or Regex/ICU)? I think I would have to make a "boost/boost.hpp" overall header to be the focal point of the framework, which may be a good idea to create anyway. How would I test it? Hmm, would anyone here like to take a challenge to create a program that uses ALL of Boost, so every symbol gets exercised? -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com

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[smart_ptr] Is smart_ptr header only?
by Daryle Walker 24 Aug '08

24 Aug '08

When trying to make an all-Boost huge library, I found some src/*.cpp files in smart_ptr's libs directory. Are these official, or can I leave them out? -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com

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Error in setup_boostbook.sh
by Manuel Fiorelli 24 Aug '08

24 Aug '08

setup_boostbook.sh (and probably the python script) fails because it attempts to download FOP using the (not existing) URL http://mirrors.ibiblio.org/pub/mirrors/apache/xmlgraphics/fop/fop-0.94-bin-… instead of http://mirrors.ibiblio.org/pub/mirrors/apache/xmlgraphics/fop/binaries/fop-… It simply misses the /binaries component inside the path. Regards, Manuel Fiorelli

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[review] FSM Review extended until August 27th
by Martin Vuille 23 Aug '08

23 Aug '08

By request, the formal review for Andrey Semashev's Finite State Machines (FSM) library has been extended and will run until August 27th. This is your last chance to submit a review and cast your vote for or against inclusion of this library into Boost. The documentation (overview and reference) is available online: http://boost-extension.redshoelace.com/docs/boost/fsm/doc/state_machine.html http://boost-extension.redshoelace.com/docs/boost/fsm/doc/reference.html The current submission is available from the sandbox vault at http://tinyurl.com/yjozfn (or http://www.boostpro.com/vault/index.php?action=downloadfile&filename=FSM.zip &directory=&PHPSESSID=48493076c1ea60ae316f7b60f15b9ed1, if you prefer.) ----------- Description ----------- "The main goals of the library are: * Simplicity. It should be very simple to create state machine using this library. * Performance. The state machine infrastructure should not be very time and memory-consuming in order to be applicable in more use cases. * Extensibility. A developer may want to add more states to the existing state machine, and this addition should be relatively safe since it shouldn't interfere with the existing states. The developer should also be able to specify additional transitions and events for the machine with minimum modifications to the existing code." "Boost.FSM vs. Boost.Statechart There is another library in Boost that provides similar functionality: Boost.Statechart. Although it currently covers almost all major Boost.FSM features and provides ones that are not supported in this library, Boost.Statechart is more targeted to creation of big and complex state machines with possibility of distributed development. But this does not come at no price and Statechart has little tools for compile-time programming and does not provide as much run-time performance as Boost.FSM does. So there are main guidelines for users to make a decision between Boost.FSM and Boost.Statechart: [...]" "The following compilers are known to have problems or most likely will have ones: * Microsoft Visual C++ 6.0 and 7.0. Most probably will fail to compile due to lack of partial template specialization support. * Borland C++ Builder 5.5.1 (free version). Fails to compile due to lack of partial template specialization and in-class using declarations support. Some other minor problems also have been noticed. Newer versions of the compiler have not been tested. * OpenWatcom 1.5. Fails to compile due to problems with Boost.MPL code. Newer versions of the compiler have not been tested. * SunPro C++ Compiler 5.5 for Solaris (SPARC). Most likely will show problems with function overload resolution. Newer versions of the compiler have not been tested." The current submission is available from the sandbox vault at http://tinyurl.com/yjozfn (or http://www.boostpro.com/vault/index.php?action=downloadfile&filename=FSM.zip &directory=&PHPSESSID=48493076c1ea60ae316f7b60f15b9ed1, if you prefer.) ---------------------------------- What to include in Review Comments ---------------------------------- Your comments may be brief or lengthy, but basically the Review Manager needs your evaluation of the library. If you identify problems along the way, please note if they are minor, serious, or showstoppers. Here are some questions you might want to answer in your review: 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? And, finally, every review should answer this question: Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. Thanks in advance for your participation in this review. MV

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[fsm] Accessing a state instance in a state machine?
by Boris 23 Aug '08

23 Aug '08

I had a quick look at the documentation of the Boost FSM library as I need to implement a simple protocol handler for a network application. The protocol handler sends and receives text messages and switches between various states. What I wonder is how I can pass for example a reference to a socket to a state so that the state can send a text message? There doesn't seem to be a way to acccess a state instance in a state machine? Boris

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For those who have/know well the g++ 4.3.0 library
by Gennaro Prota 23 Aug '08

23 Aug '08

Hi, looking at the trunk regression report for dynamic_bitset, there's a stream inserter failure on gcc 4.3.0 which puzzles me :-) It's on Sandia-gcc, and happens only when -std=gnu++0x is absent. Any clue? -- Genny

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[mpl, fusion] minimal conforming sequence
by Peter Dimov 23 Aug '08

23 Aug '08

Hi, Assume that I have a custom type sequence S that has two operations, size<S>::value and element<S,I>::type (with whatever spelling). What needs to be done to adapt S into a conforming MPL or Fusion sequence? In a perfect world, the answer would not require the inclusion any MPL or Fusion headers and would consist of three specializations. ;-)

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New libraries should provide forward declarations?
by Peter Bartlett 22 Aug '08

22 Aug '08

Hi Boost community, Would it practical to add a rule of thumb to the developer guidelines that library developers should offer a fwd declaration header for their library when possible? For me the rationale is as follows: - Boost headers are relatively heavy includes - Pre-compiled headers are only available on a subset of compilers. - Client side forward declarations are often problematic. E.g. - - Boost.Tuple: redeclarations of default template arguments are illegal (although MSVC lets you do it if you are prepared to suffer a warning) so including boost/tuple.hpp after mylibraryutils/boost_tuple_fwd.hpp is illegal. - - Boost.Function : The removal of the allocator template parameter has broken our code when we experimentally checked the 1.36 beta, as our forward declarations of Boost.Functions are now wrong. The existence of boost/tuple/tuple_fwd.hpp and boost/function/function_fwd.hpp would thus have significantly improved the user experience in my case. Thanks for listening, Pete Bartlett

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[log] Filter bug (Andrey? :)
by Boris 22 Aug '08

22 Aug '08

Andrey, can you tell me why the following program writes the second message? ---------- #include <boost/log/sources/severity_logger.hpp> #include <boost/log/logging_core.hpp> #include <boost/log/utility/init/to_console.hpp> #include <boost/log/utility/init/to_file.hpp> #include <boost/log/utility/init/common_attributes.hpp> #include <boost/log/formatters/format.hpp> #include <boost/log/formatters/attr.hpp> #include <boost/log/formatters/date_time.hpp> #include <boost/log/formatters/message.hpp> #include <boost/log/filters/attr.hpp> #include <boost/shared_ptr.hpp> enum severity_level { info, warn, error }; boost::log::sources::severity_logger logger; int main() { boost::shared_ptr<boost::log::sinks::synchronous_sink<boost::log::sinks::text_ostream_backend>> sink = boost::log::init_log_to_file("test.txt"); boost::log::add_common_attributes(); sink->locked_backend()->set_formatter(boost::log::formatters::format("[%1%] %2%") % boost::log::formatters::attr("Severity") % boost::log::formatters::message()); sink->locked_backend()->auto_flush(true); boost::log::logging_core::get()->set_filter(boost::log::filters::attr<int>("Severity") > info); BOOST_LOG_SEV(logger, warn) << "first message"; // Message is not written. boost::log::logging_core::get()->set_filter(boost::log::filters::attr<int>("Severity") < warn); BOOST_LOG(logger) << "second message"; // Why is this message written?? } ---------- The first message is not written as the severity level warn is greater than info. However for the second message the default severity level info is smaller than warn. Thus I would expect the second message is not written either? Is this a bug? Boris

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[range] No iterator_range::const_reference
by Francois Barel 22 Aug '08

22 Aug '08

Hi list, boost::iterator_range currently contains both 'iterator' and 'reference' typedefs, and yet only a 'const_iterator' one (no 'const_reference'). This can be a problem with Spirit actions (compilation errors, see trac ticket #2234 - http://svn.boost.org/trac/boost/ticket/2234) After removing Spirit code, it boils down to: //////////////////// #include <boost/spirit/include/phoenix_stl.hpp> #include <boost/range/iterator_range.hpp> int main() { typedef const boost::iterator_range< const char* > cir; boost::phoenix::stl::front::result< cir > foo; // compilation error return 0; } //////////////////// The problem comes from the instantiation of boost::phoenix::stl::front::result< const iterator_range<...> > which, since its template argument is const, accesses its const_reference typedef -- which doesn't exist in iterator_range. Does it make sense / is it possible to add a const_reference typedef in iterator_range? Thanks, Francois

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boost for embedded?
by Fleming, Edward 22 Aug '08

22 Aug '08

Newbie question if anyone can help: Is there a makefile for building boost (especially regex) with a Microsoft compiler for Windows Embedded CE/Mobile (ARM platform)? Any information would be appreciated! (howto, location of makefile, etc.) Thanks, Ed ------------------------- This e-mail and any attachments may contain confidential material for the sole use of the intended recipient. If you are not the intended recipient, please be aware that any disclosure, copying, distribution or use of this e-mail or any attachment is prohibited. If you have received this e-mail in error, please contact the sender and delete all copies. Thank you for your cooperation

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_ReadWriteBarrier as memory fence, or not?
by Simon Thornington 22 Aug '08

22 Aug '08

Hi folks, Quick question about the use of _ReadWriteBarrier (Win32 MSVC): According to http://msdn.microsoft.com/en-us/library/ms684208(VS.85).aspx , this compiler intrinsic doesn't generate any memory fencing instructions at all, it's strictly a compiler optimization barrier. I was wondering if someone had any documentation to contradict this, or if boost is relying on the new volatile semantics in VC2005 to ensure the fence? It sure looks like it's being used as if it were a real memory fence, but I am not sure that's the case. I'm not an expert though. Cheers, Simon.

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[fsm review] Not quite a review
by Darryl Green 22 Aug '08

22 Aug '08

I don't know if I will have time to do a proper review of the library. The following are my notes on it so far. I've read the documentation for the libary, but haven't tried to use it. Good points: Simple. Relatively fast at runtime. Docs are quite good, but perhaps lack enough rationale style documentation on how the library models FSM concepts. Would benefit from some "how to" examples of more realistic usage and some "how to" docs on translating FSMs expressed using UML (or Harel) statecharts into a form implementable using FSM. Bad points: Unusual terminology. While there are obvious performance reasons for avoiding the Boost Statechart approach of applying an RAII model to state activation, it is not clear why at least basic concepts and terminology have not been used in FSM - especially as most Statechart terminology and FSM behavioural concepts are straight from UML terminology (it is a standard, you could pick another one, but why not stick with this one)? Note that this is *not* a request that the library include more features - just for some consistent ones. Some idiosyncratic behaviour. The FSM delivers the event to the on_process() handler in the "switched to" state when the transition is specified using the transition map, while delivering it to the on_process() handler in the current state if no transition map entry matches. There are warnings against mixing the transition map and switch_to() approaches to FSM specification, but even so it seems that the 2 uses of the on_process() handler are completely different. Would it not be better to have a model similar to Boost.Statechart where a custom reaction (implemented by a react() method) in a state is used to perform actions within the start state, generally including making a (gated) transition, while any action to occur on a transition is specified as part of the transition? Further, that transition action should be performed after the exit action of the current state and before the entry action of the new state. No event queuing mechanism, so no way to post an event while processing an event - although I see there has been some discussion about adding event deferral - which might be (almost) enough. Slow at compile time. I have not tested as yet, but if it is as slow as the mpl example state machine implementation, this will be a problem (I have previously had to abandon use of the MPL FSM due to compilation time issues on only moderately complex FSMs). Lacks real world use? I don't know if that is true, but I haven't seen anything other than toy examples. I was thinking that in the cases where the performance of Statechart was inadequate for complex augumented FSM implementation I would consider using FSM - but it would mean building a fair bit of additional scaffolding around FSM - maybe this should be part of the library? Or at least some examples of ideomatic use should be included? I found myself wondering if anyone had actually tried to use it in this way? Conversely, I don't find it compelling for implementing something like a lexer or even the terminal emulator example. What is the application domain? Not quite a conclusion: This is a hard one. At one extreme, Boost.Statechart is extremely powerful and well worth using in certain application domains (but there are performance implications), and at the other, as has been illustrated, various hand-rolled solutions of varying degrees of elegance get the job done. There seems to be a lot of space in between, and I'm not sure that the proposed FSM library fills enough of it.

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[lambda][bind] trivial bind fails when lambda and bind are in the same source file
by Michael Marcin 22 Aug '08

22 Aug '08

My environment is VC9 SP1 and Boost 1.35. This problem also occurs in boost 1.36. I had some code using lambda which worked fine for several weeks until today when someone else included my header in his code which used bind. He told me my code was broken but my tests ran fine. It took us a few minutes to find the problem and I've distilled it to this trivial reproducible case. #include <boost/bind.hpp> #include <boost/lambda/bind.hpp> void foo( int ) { } int main() { using namespace boost::lambda; bind( &foo, _1 ); } Compiling this gives: error C2872: '_1' : ambiguous symbol 1> could be 'c:\vfx\third_party\boost\1_35_0\boost\lambda\core.hpp(69) : boost::lambda::placeholder1_type &boost::lambda::`anonymous-namespace'::_1' 1> or 'c:\vfx\third_party\boost\1_35_0\boost\bind\placeholders.hpp(42) : boost::arg<I> `anonymous-namespace'::_1' 1> with 1> [ 1> I=1 1> ] I can make the problem go away by changing main to int main() { using boost::lambda::_1; using boost::lambda::bind; bind( &foo, _1 ); } but the actual code uses a lot more lambda and the amount of using directives I would need makes the code longer than rolling my own functor. I could also alias lambda to make main look something like int main() { namespace bll = boost::lambda; bll::bind( &foo, bll::_1 ); } but this introduces a lot of noise into the lambda expression and makes complex lambdas unreadable. Is this accepted behavior? Thanks, Michael Marcin

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