April 2012 - Boost - lists.boost.org

[utility] convention inconsistencies
by lcaminiti 29 Apr '12

29 Apr '12

Hello all, I'm adding IdentityType to Boost.Utility and I have a couple of question about conventions: 1) Is there a reason why utility.hpp does not include all headers in boost/utility/? 2) Is there a reason why in the Documentation the utility sub-libraries are not named Boost.Utility/EnableIf bust just Boost.EnableIf? http://www.boost.org/doc/libs/1_49_0/ In boost/utility/ directory: addressof.hpp base_from_member.hpp binary.hpp compare_pointees.hpp declval.hpp enable_if.hpp identity_type.hpp in_place_factory.hpp result_of.hpp swap.hpp typed_in_place_factory.hpp value_init.hpp But boost/utility.hpp includes only some of those: #ifndef BOOST_UTILITY_HPP #define BOOST_UTILITY_HPP #include <boost/utility/addressof.hpp> #include <boost/utility/base_from_member.hpp> #include <boost/utility/binary.hpp> #include <boost/utility/enable_if.hpp> #include <boost/checked_delete.hpp> #include <boost/next_prior.hpp> #include <boost/noncopyable.hpp> #endif // BOOST_UTILITY_HPP Thanks. --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-utility-convention-inconsistencies… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[function] The cost of boost::function
by Michael Kochetkov 28 Apr '12

28 Apr '12

Hello, as far as I subscribed to boost mail list for a reason I have decided to share an interesting (at least for me) observation of boost::function facility I have encountered several years ago. The observation is about the cost of the solution and you probably may be interested if you use boost in your production. Let us consider the following code: #include <boost/bind.hpp> #include <boost/function.hpp> inline int g(int i) { return ++i; } int main() { // AAAAA boost::function< int (int) > f1 = boost::bind(&g, _1 ); f1(1); // BBBB boost::_bi::bind_t<int,int (*)(int),boost::_bi::list1<boost::arg<1> > > f2 = boost::bind(&g, _1 ); f2(1); // CCCC auto f3 = boost::bind(&g, _1 ); f3(1); } I have compiled it with Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 16.00.40219.01 for 80x86 the following way (maximal optimization): cl -EHsc -Ox -GL -Ob2 -Oi -Fa -IE:\Work\3dparty\boost_1_48_0 m054.cpp The resulting code for AAAA is: ; Line 10 mov eax, OFFSET ?g@@YAHH@Z ; g mov DWORD PTR $T109940[esp+60], eax mov eax, DWORD PTR $T109845[esp+64] lea ecx, DWORD PTR $T109940[esp+60] push ecx mov DWORD PTR $T109940[esp+68], eax call ?has_empty_target@function@detail@boost@@YA_NZZ ; boost::detail::function::has_empty_target add esp, 4 test al, al jne SHORT $LN20@main mov edx, DWORD PTR $T109940[esp+60] mov eax, DWORD PTR $T109940[esp+64] mov ecx, OFFSET ?stored_vtable@?1???$assign_to@V?$bind_t@HP6AHH@ZV?$list1@U?$arg@$00@boost@@ @_bi@boost@@@_bi@boost@@@?$function1@HH@boost@@AAEXV?$bind_t@HP6AHH@ZV?$list 1@U?$arg@$00@boost@@@_bi@boost@@@_bi@2@@Z@4U?$basic_vtable1@HH@function@deta il@2@B ; `boost::function1<int,int>::assign_to<boost::_bi::bind_t<int,int (__cdecl*)(int),boost::_bi::list1<boost::arg<1> > > >'::`2'::stored_vtable or ecx, 1 mov DWORD PTR _f1$[esp+68], edx mov DWORD PTR _f1$[esp+72], eax mov DWORD PTR _f1$[esp+60], ecx jmp SHORT $LN18@main $LN20@main: mov DWORD PTR _f1$[esp+60], 0 $LN18@main: ; Line 11 lea ecx, DWORD PTR _f1$[esp+60] mov DWORD PTR __$EHRec$[esp+68], 0 call ??R?$function1@HH@boost@@QBEHH@Z ; boost::function1<int,int>::operator() The resulting code for BBBB is: ; Line 15 push 1 call ?g@@YAHH@Z ; g add esp, 4 The resulting code for CCCC is: ; Line 19 push 1 call ?g@@YAHH@Z ; g add esp, 4 I have learned that personally I shall never use boost::function. You probably may want to investigate such a code bloat. Though it is probably the known and expected behavior. And I do agree that CCCC is not quite relevant here. Just for information. -- Michael Kochetkov P.S. The traditional full story for AAAA, that includes intermediate calls. Though it is not really full -- I have given up for three more calls inside the boost::function1<int,int>::operator() function. ; // AAAAA ; boost::function< int (int) > f1 = boost::bind(&g, _1 ); ; f1(1); 002661B9 mov eax,261170h 002661BE mov dword ptr [esp+4],eax 002661C2 mov eax,dword ptr [esp+8] 002661C6 lea ecx,[esp+4] 002661CA push ecx 002661CB mov dword ptr [esp+0Ch],eax 002661CF call 00261160 002661D4 add esp,4 002661D7 test al,al 002661D9 jne 002661F9 002661DB mov edx,dword ptr [esp+4] 002661DF mov eax,dword ptr [esp+8] 002661E3 mov ecx,26A028h 002661E8 or ecx,1 002661EB mov dword ptr [esp+14h],edx 002661EF mov dword ptr [esp+18h],eax 002661F3 mov dword ptr [esp+0Ch],ecx 002661F7 jmp 00266201 002661F9 mov dword ptr [esp+0Ch],0 00266201 lea ecx,[esp+0Ch] 00266205 mov dword ptr [esp+38h],0 0026620D call 002611D0 ; ?has_empty_target@function@detail@boost@@YA_NZZ ; boost::detail::function::has_empty_target 00DD1160 xor al,al 00DD1162 ret ; ??R?$function1@HH@boost@@QBEHH@Z ; boost::function1<int,int>::operator() 00DD11D0 push 0FFFFFFFFh 00DD11D2 push 0DD7810h 00DD11D7 mov eax,dword ptr fs:[00000000h] 00DD11DD push eax 00DD11DE sub esp,58h 00DD11E1 push esi 00DD11E2 mov eax,dword ptr ds:[00DDB038h] 00DD11E7 xor eax,esp 00DD11E9 push eax 00DD11EA lea eax,[esp+60h] 00DD11EE mov dword ptr fs:[00000000h],eax 00DD11F4 mov eax,dword ptr [ecx] 00DD11F6 test eax,eax 00DD11F8 jne 00DD1248 00DD11FA lea eax,[esp+0Ch] 00DD11FE push eax 00DD11FF lea ecx,[esp+14h] 00DD1203 mov dword ptr [esp+10h],0DDA008h 00DD120B call 00DD187F 00DD1210 mov dword ptr [esp+10h],0DDA058h 00DD1218 lea eax,[esp+10h] 00DD121C lea esi,[esp+1Ch] 00DD1220 mov dword ptr [esp+68h],0 00DD1228 call 00DD1600 00DD122D lea esi,[esp+3Ch] 00DD1231 mov byte ptr [esp+68h],1 00DD1236 call 00DD1640 00DD123B push 0DDA7A8h 00DD1240 mov ecx,esi 00DD1242 push ecx 00DD1243 call 00DD23CA 00DD1248 and eax,0FFFFFFFEh 00DD124B mov edx,dword ptr [eax+4] 00DD124E add ecx,8 00DD1251 push 1 00DD1253 push ecx 00DD1254 call edx 00DD1256 add esp,8 00DD1259 mov ecx,dword ptr [esp+60h] 00DD125D mov dword ptr fs:[0],ecx 00DD1264 pop ecx 00DD1265 pop esi 00DD1266 add esp,64h 00DD1269 ret

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[1.50] Is there a schedule?
by John Maddock 27 Apr '12

27 Apr '12

OK, so it's too soon at present anyway, but should there be some sort of schedule on the calendar so we all know where we are? Cheers, John.

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Boost.Variant known_get
by David Sankel 27 Apr '12

27 Apr '12

I noticed the detail::known_get function in boost variant. Is there any reason this function, which would be useful in high performance scenarios, is not exposed as part of the rest of the interface? David -- David Sankel Sankel Software www.sankelsoftware.com 585 617 4748 (Office)

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Boost.units autoscaling doesn't seem to work with the measurement type.
by Paul A. Bristow 27 Apr '12

27 Apr '12

I have previously used Boost.Units and autoscaled using << engineering_prefix nicely, and this works as expected for quantity of type double. but it seems that code that I believe worked previously does not autoscale when using a *user-defined type*, like the measurement example in kitchen_sink.cpp. To confirm this, I have added after //[kitchen_sink_snippet_8 in kitchen_sink.cpp at line 445 a measurement quantity where the length is long enough to trigger conversion to km, thus quantity<length,measurement<double> > biglen(measurement<double>(12345.0,123.0)*meters); std::cout << "Biglen autoscaled "<< engineering_prefix << biglen << std::endl; but I get a *unscaled* value :-( Biglen autoscaled 12345(+/-123) m rather than the expected conversion to kilometers 12.345(+/- 0.123) km Am I doing something wrong, or has something changed? Thanks Paul PS Using Microsoft Visual Studio 2010 Version 10.0.40219.1 SP1Rel Microsoft .NET Framework Version 4.0.30319 SP1Rel Boost-trunk (Boost.1.49) --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow(a)hetp.u-net.com

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Re: [boost] [decimal] Proposed portable implementation of std::decimal
by Josh Quigley 27 Apr '12

27 Apr '12

As previously mentioned, the plan is to wire up existing (C interface) packages to a C++ std::decimal, raising licensing issues around the 3rd party code. I don't believe there is an issue, the licences are very short and read like plain English to me. Also, gcc includes both of these in it's implementation, and distributes under an open licence. I've copy-pasted below the relevant bits out of the EULAs. If anyone thinks there might be an issue, please let me know. INTEL EULA Copyright (c) 2011, Intel Corp. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, his list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of Intel Corporation nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. IBM Licence Copyright (c) 1995-2012 International Business Machines Corporation and others All rights reserved. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, provided that the above copyright notice(s) and this permission notice appear in all copies of the Software and that both the above copyright notice(s) and this permission notice appear in supporting documentation.

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Variadic to Head/Tail TMP List
by Fernando Pelliccioni 27 Apr '12

27 Apr '12

Hi, Is this piece of code useful ? http://pastebin.com/tRrqVHTw The purpose is to tranform code like the following: typedef cons<int, cons<float, cons<char, cons<string>>>> t0; // fusion::cons or similar data structures in typedef chain_generator<cons, nil> cons_gen; typedef cons_gen::gen<int, float, char, std::string>::type t1; I don't know if there is something similar in a library. I think it could be useful. Compiler tests: GCC 4.7 -> Compiler Error GCC 4.7.1 & Trunk -> OK http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53108 Clang Trunk -> OK MSVC 11 beta -> has no Variadic Templates Regards, FP.

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Boost.ntree_container (bi_tree, quad_tree, oct_tree, etc ptr containers) Is there any interest in this?
by Dan Walters 27 Apr '12

27 Apr '12

Hi all, I am proposing adding spacial containers for efficiently storing and accessing data of a spacial nature in fixed size trees. n-tree data structures would be useful where data relates to a 1D, 2D or 3D location, providing n-array searching of an n-array volume. N-tree data structures are commonly used in 3d applications, and are rarely particularly specialized. Their use is fundamental however they are frequently written by application programmers, due to a lack of free open source implementations (to the limit of my research). Their sophistication, like any container, is slim but easy to get wrong and beyond the ability and time contraints that should be assumed of the application programmer. It is a flexible and standard enough concept that a single implementation can be expected to meet a majority of requirements. I think there is the opportunity to create a solid implementation of templated n-tree pointer containers. The ntree container would be a tree representing an narray of elements with all dimensions being the same and being a power of two. The tree is memory efficient where areas within the volume are not occupied, and so "branches" and "leaves" are not created. The tree is well suited to geometrical operations such as ray picking or plane culling of the volume. An n-tree structure could be used in the place of any sparely populated n dimensional array where memory saving is the objective. The existing libraries I have found are licensed under GNU licenses. A ntree container should implement: get reset overloaded (array style) operators Optional implementations: views - a subset object representing an area or volume within the tree for accelerated access to a group of leaves that are positioned near to each other raycasting plane culling (getting leaves within a set of planes) etc. Is there interest in such a library? Many thanks, Dan

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[interprocess] ppc compile error
by Tim Blechmann 27 Apr '12

27 Apr '12

hi all, one of my users reported the following compile error when building my application for ppc/osx(10.5): /var/folders/+D/+DUo7PxAEgCfHTatXKIeMU+++TI/-Tmp-//ccPubDFs.s:5566:Unknown pseudo-op: .subsection /var/folders/+D/+DUo7PxAEgCfHTatXKIeMU+++TI/-Tmp-//ccPubDFs.s:5566:Rest of line ignored. 1st junk character valued 50 (2). /var/folders/+D/+DUo7PxAEgCfHTatXKIeMU+++TI/-Tmp-//ccPubDFs.s:5569:Unknown pseudo-op: .previous the specific part of the assembly is: -- 4010 L686: 4011 sync 4012 lwarx r8,0,r11 4013 cmpw r8, r3 4014 bne- 2f 4015 stwcx. r9,0,r11 4016 bne- 2f 4017 addi r2,0,1 4018 1:.subsection 2 4019 2: addi r2,0,0 4020 b 1b 4021 .previous 4022 4023 cmpwi cr7,r2,0 4024 mr r3,r8 4025 beq cr7,L686 4026 stw r8,20(r10) 4027 mulli r3,r8,12 4028 add r3,r3,r10 4029 addi r3,r3,28 4030 bl L__ZNK5boost12interprocess10offset_ptrIfimLm0EE14to_raw_pointerEv$stub 4031 addi r1,r1,96 4032 stw r3,4(r30) 4033 lwz r0,8(r1) 4034 nop 4035 lmw r30,-8(r1) 4036 mtlr r0 4037 blr -- this error occurs with boost-1.49.0 ... is this a known issue or some workaround? thanks, tim

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[OT][RFC] standardized compile-time reflection
by Matus Chochlik 27 Apr '12

27 Apr '12

Dear members of the Boost community, (Sorry for being slightly off-topic here) In the last couple or years I've been working on the design and implementation of portable reflection in C++. I've written several reflection libraries (that are hopefuly gradually improving). For the latest incarnation see the Mirror reflection utilities written in C++11: http://kifri.fri.uniza.sk/~chochlik/mirror-lib/html/ Recently I've learned that the Standardization Committee has issued a call for proposals for additions to the standard to the wider community, so I've decided to write down my own ideas on how compile-time reflection should look like in C++. Afterwards I discussed it with several people including Dean Michael Berris, who is the co-author of n3340 "Rich pointers" and is also interested in adding run-time (and static) reflection to C++. We've decided that we merge the ideas from my paper into his proposal (which has not happened yet and will probably take a while). However, n3340 deals with more than just static reflection, so I would like to start a discussion and ask the members of the Boost community for their opinions about the compile-time-specific parts that are described in the following paper, before writing the final proposal: http://kifri.fri.uniza.sk/~chochlik/jtc1_sc22_wg21/std_cpp_refl.pdf It is a bit lengthy so you can skip sections 1., 2. and probably also section 3., if you are knowledgeable about the domain. The most important parts are: the whole section 4. "Technical specification" and also 5., 6. and 7. Section 7. "Unresolved issues" lists several important things that need to be worked out and 3. has some rationale for the design decisions. Note that the paper has the basic structure of a standard proposal, but is not written in standardese nor is it "polished" (since it will be merged into another paper and probably re-worded). It is my first attempt at a standard proposal and I'm not a member of the Committee so please bear with me :-). Dean and I have also independently decided to write proof-of-concept implementations - compiler extensions for clang and gcc respectivelly. The sources for the gcc plugin are hosted here: https://github.com/matus-chochlik/std_cpp_refl It's in a very early stage, but if someone has some tips or hints they'll be welcome. Thanks in advance for any (negative or positive) feedback. Best regards, Matus Chochlik

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[assign] How to create a container wrapper for tuple_list_of
by Robert Dailey 26 Apr '12

26 Apr '12

I have a vector of boost::tuple objects that is a member variable in a class of mine. I want to be able to create an instance of my wrapper class and construct it off of a tuple_list_of(), and essentially forward those values to the container itself. I haven't seen a way to do this yet. An example is below. Note that my constructor in the class was my attempt to get this working, but instead it will not compile. For some reason boost.assign thinks that the EnumErrorInfo class is the container. template<class T> class EnumErrorInfo { public: typedef boost::tuple<T, char const*, char const*> Tuple; typedef std::vector<Tuple> TupleVector; EnumErrorInfo( TupleVector const& assignment ) : m_errorInfo( assignment ) {} Tuple const& getErrorInfo( T error_code ) { TupleVector::const_iterator it = std::find_if( m_errorInfo.begin(), m_errorInfo.end(), MatchErrorCodePred( error_code ) ); if( it != m_errorInfo.end() ) { return *it; } static Tuple const unknown_info( error_code, "????", "No error info available for this code" ); return unknown_info; } private: class MatchErrorCodePred { public: MatchErrorCodePred( T error_code ) : m_errorCode( error_code ) {} bool operator() ( Tuple const& t ) { return t.get<0>() == m_errorCode; } private: DomInterfaceErrors m_errorCode; }; TupleVector m_errorInfo; }; And here is how I'd like to initialize the class: EnumErrorInfo<DomInterfaceErrors> g_errorInfo = tuple_list_of ( GDE_OK, "GDE_OK", "DBL: Opeartion successfully completed" ) ( GDE_GDD_DIRUSERS, "GDE_GDD_DIRUSERS", "AQX: Unable to get directory users." ) ;

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[interprocess] Sharing shared_memory_object across processes?
by Joseph Van Riper 26 Apr '12

26 Apr '12

I either do not understand what I am seeing, or I may have stumbled upon a bug, at least in a Windows environment. Or, of course, my expectations may be unrealistic. The short of this is that when I create a boost::interprocess::shared_memory_object that isn't removed for the duration of the program's run, the reading program's run can't seem to open the shared_memory_object, despite creating a boost::interprocess::permissions object and calling 'set_unrestricted()'. I get an exception indicating that access is denied. If nothing else, the code I've provided is an interprocess version of the classic read-writer's problem, second version (writers preferred). It may be of use to someone with a little cleaning. Environment: Compiler: MSVC++ 10 OS: Win 7 Pro, 64-bit. Steps to reproduce: 1. In VC++ 10, create an empty command-line project. 2. Replace contents of your .cpp with the code in this e-mail. 3. Compile. 4. Run the executable twice, first with an argument, next without. Expected results: The executable run without arguments indicates how much data was transferred on the same line. Actual results: The executable run without arguments complains that access is denied. NOTE: If you #define BOLD_NEW_TEST and recompile, this program runs according to expectations. This causes the objects to be compiled in a way where the shared_memory_objects only last for as long as it takes to write or read the data. I suspect this shouldn't be necessary, but perhaps I'm wrong. The error is especially peculiar to me, as I can open the file itself with a text editor. It doesn't seem like it should be denied. - Trey

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[result_of] Make `cpp0x_result_of_impl` public
by Michel Morin 26 Apr '12

26 Apr '12

There are two implementations of boost::result_of: a TR1-style implementation and a decltype-based implementation. While the TR1-style implementation has a public interface `boost::tr1_result_of`, decltype-based one doesn't have a public interface. By defining BOOST_RESULT_OF_USE_DECLTYPE, boost::result_of use decltype-based implementation. But this is not always a viable solution, since this breaks some Boost libraries. So how about adding `boost::cxx11_result_of` as public interface of the decltype-based implementation? Attached a patch to add `boost::cxx11_result_of`. (This patch also changes the name of `cpp0x_result_of_impl` to `cxx11_result_of_impl` to reflect the recent discussion on the cpp/cxx naming.) P.S. Is it worth trying to use this `boost::cxx11_result_of` in `boost::transform_iterator` code on trunk? Regards, Michel

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[result_of] Regression: compilation errors on C++03 compilers when defining BOOST_RESULT_OF_USE_DECLTYPE
by Michel Morin 25 Apr '12

25 Apr '12

If we define BOOST_RESULT_OF_USE_DECLTYPE, boost::result_of tries to use decltype-based implementation even on C++03 compilers. This causes compilation errors and it is a regression on C++03 compilers. Is it intentional change? Regards, Michel

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[utility][assert]
by Yechezkel Mett 25 Apr '12

25 Apr '12

I noticed that when BOOST_ENABLE_ASSERT_HANDLER is defined, BOOST_ASSERT calls boost::assertion_failed whether or not NDEBUG is defined, but BOOST_ASSERT_MSG calls boost::assertion_failed_msg only if NDEBUG is not defined. Is there a reason for this difference?

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[exception] applying patch for issue #6349
by David Deakins 24 Apr '12

24 Apr '12

Hi Emil, Since the issue in item #6349 is disrupting the Windows CE test results for many libraries, do you mind if I go ahead and apply the patch attached to that item? Thanks, -Dave

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[Iterator] Fixing the default reference type of transform_iterator (#5127)
by Michel Morin 24 Apr '12

24 Apr '12

The default reference type of transform_iterator should be boost::result_of<const UnaryFunction(Iterator::reference)> rather than boost::result_of<UnaryFunction(Iterator::reference)> since the dereference operator of transform_iterator is a const member function. Ticket #5127 describes this bug https://svn.boost.org/trac/boost/ticket/5127 and the ticket has a patch. Jeff, could you apply the patch, if it looks OK? Regards, Michel

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[contract] assertion requirements as meta-functions or not?
by lcaminiti 24 Apr '12

24 Apr '12

Hello all, Boost.Contract allows to specify "assertion requirements": /assertion-condition/, requires /assertion-requirement/ If the requirement is not met then the assertion condition is neither compiled nor checked at run-time. Question: Shall the assertion-requirement be a nullary boolean meta-function or just a static boolean value? For example: CONTRACT_FUNCTION( template( typename T ) requires( boost::LessThanComparable<T> ) (T const&) (min) ( (T const&) x, (T const&) y ) postcondition( auto result = return, x < y ? result == x : result == y, requires boost::has_equal_to<T>::value // static boolean ) ) { return x < y ? x : y; // OK: T is less than comparable `<`. } For now, the assertion requirement is a static boolean value so it can be more easily manipulated (using !, &&, ||, etc instead of mpl::not, mpl::and, mpl::or, etc). However, is there any strong reason for marking the assertion requirement a nullary boolean meta-function instead like the following code? x < y ? result == x : result == y, requires boost::has_equal_to<T> // meta-function Thanks. --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-contract-assertion-requirements-as… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[Fusion] Patch: fixing some test failures on clang
by Michel Morin 24 Apr '12

24 Apr '12

The following tests of Boost.Fusion fail on clang trunk in a C++11 mode with libc++. * io.test * deque_construction.test * deque_misc.test * std_tuple_iterator.test * invoke.test Attached a patch for fixing two failures (io.test and std_tuple_iterator.test) of them. Regards, Michel

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Search a vector of tuples?
by Robert Dailey 23 Apr '12

23 Apr '12

Is there a method in the boost library to iterate a vector of boost::tuple objects, comparing the 1st element in the tuple of each tuple to a value that I specify? My tuple is setup like so: typedef boost::tuple<int, int, char const*> Tuple; typedef std::vector<Tuple> ErrorStringMap; ErrorStringMap mystrings = tuple_list_of (10, "10", "ten") (20, "20", "twenty") (30, "30", "thirty") (10, "10", "ten"); I want to search the vector of tuples and do something with every tuple that has the number 10 as the first element in the tuple.

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[concept_check] addable
by lcaminiti 23 Apr '12

23 Apr '12

Hello all, Does this Addable concept definition make sense to you? Is there any error? #include <boost/concept_check.hpp> template<typename T> struct Addable { // User-defined concept. BOOST_CONCEPT_USAGE(Addable) { return_type(x + y); // Check addition `T operator+(T x, T y)`. } private: T x; T y; void return_type(T const&); // Used to check addition returns type `T`. }; It's not making Sun's linker happy: "/opt/sunstudio12.1/bin/CC" -g -library=stlport4 -features=tmplife -features=tmplrefstatic -library=stlport4 -m64 -KPIC -o "/scratch2/kbelco/boost/results/boost/bin.v2/libs/local_function/test/typeof_seq.test/sun-5.10/debug/address-model-64/stdlib-sun-stlport/typeof_seq" "/scratch2/kbelco/boost/results/boost/bin.v2/libs/local_function/test/typeof_seq.test/sun-5.10/debug/address-model-64/stdlib-sun-stlport/typeof_seq.o" -Bdynamic -lrt -Bstatic -Bdynamic Undefined???first referenced symbol ??? in file void Addable<int>::return_type(const int&) /scratch2/kbelco/boost/results/boost/bin.v2/libs/local_function/test/typeof_seq.test/sun-5.10/debug/address-model-64/stdlib-sun-stlport/typeof_seq.o ld: fatal: Symbol referencing errors. No output written to /scratch2/kbelco/boost/results/boost/bin.v2/libs/local_function/test/typeof_seq.test/sun-5.10/debug/address-model-64/stdlib-sun-stlport/typeof_seq But the error might also be somewhere else in the program that checks the concept, I'm still debugging... Thanks a lot. --Lorenzo -- View this message in context: http://boost.2283326.n4.nabble.com/boost-concept-check-addable-tp4572138p45… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[filesystem] #6521 Directory listing using C++11 range-based for loops
by Beman Dawes 23 Apr '12

23 Apr '12

Ticket #6521 requests adding: class directory{ path p_; public: inline directory(path p):p_(p){} directory_iterator begin(){ return directory_iterator(p_); } directory_iterator end(){ return directory_iterator(); } }; so that that a range-based for loop can be used: for (auto itr : directory(".")) { cout << itr.path() << endl; } The above works as expected on GCC 4.6 and VC++ 11 beta. Is that the best way for filesystem directory iteration to support range-based for? Provide a class directory_tree for recursive iteration? --Beman

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1.50 release calendar
by Vicente J. Botet Escriba 23 Apr '12

23 Apr '12

Hi, I would like to know the 1.50 release calendar so that I can plan with Anthony Williams the merge to release of Boost.Thread of version 3. Which is the last day to merge to release a big change? Thanks for all, Vicente

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[range] Question about adapted range safety given C++11 auto
by Beman Dawes 22 Apr '12

22 Apr '12

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3350.html claims: "Boost's range library focuses on defining a set of Range concepts that allow Containers to be Ranges. Because Containers are heavy-weight, this forces Boost to use references for all of their uses of Ranges, including Ranges that are captured by Range Adapters. This worked fine in C++98, where users couldn't name the types of the Range Adapters in order to declare local variables, but with C++11's auto keyword, users can now save adapted ranges. Since Boost's adapted ranges capture references to their arguments, which can be temporaries, this is no longer a safe design." Is this claim correct? If so, what's the real-world impact? --Beman

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[context] [windows] Intel C++ and GCC Support?
by Joshua Boyce 22 Apr '12

22 Apr '12

I notice that Boost.Context only seems to support MSVC under Windows, and attempts to compile it under GCC or Intel C++ will fail because it's not correctly assembling fcontext_i386_ms_pe_masm/fcontext_x86_64_ms_pe_masm. e.g. Under Intel I get: intel-win.compile.asm > C:\Users\Josh\Documents\code\boost-trunk\bin.v2\libs\context\build\intel-win\debug\address-model-64\architecture-x86\link-static\runtime-link-static\threading-multi\asm\fcontext_x86_64_ms_pe_masm.obj '-c' is not recognized as an internal or external command, operable program or batch file. > -c -Zp4 -Cp -Cx -DBOOST_ALL_NO_LIB=1 -DWINVER=_WIN32_WINNT_VISTA > -D_WIN32_WINNT=_WIN32_WINNT_VISTA -DBOOST_ALL_NO_LIB=1 > -DWINVER=_WIN32_WINNT_VISTA -D_WIN32_WINNT=_WIN32_WINNT_VISTA /Zi /Zd /W3 > -Fo > "C:\Users\Josh\Documents\code\boost-trunk\bin.v2\libs\context\build\intel-win\debug\address-model-64\architecture-x86\link-static\runtime-link-static\threading-multi\asm\fcontext_x86_64_ms_pe_masm.obj" > "C:\Users\Josh\Documents\code\boost-trunk\libs\context\src\asm\fcontext_x86_64_ms_pe_masm.asm" > ...failed intel-win.compile.asm > C:\Users\Josh\Documents\code\boost-trunk\bin.v2\libs\context\build\intel-win\debug\address-model-64\architecture-x86\link-static\runtime-link-static\threading-multi\asm\fcontext_x86_64_ms_pe_masm.obj... Whilst under GCC (via MinGW-w64) I get: Jamfile</C:/Users/Josh/Documents/code/boost-trunk/libs/context/build>.masm64 C:\Users\Josh\Documents\code\boost-trunk\bin.v2\libs\context\build\gcc-mingw-4.7.0\release\address-model-64\architecture-x86\debug-symbols-on\link-static\runtime-link-static\threading-multi\asm\fcontext_x86_64_ms_pe_masm.o 'ml64' is not recognized as an internal or external command, operable program or batch file. ml64 /c /Fo"C:\Users\Josh\Documents\code\boost-trunk\bin.v2\libs\context\build\gcc-mingw-4.7.0\release\address-model-64\architecture-x86\debug-symbols-on\link-static\runtime-link-static\threading-multi\asm\fcontext_x86_64_ms_pe_masm.o" "C:\Users\Josh\Documents\code\boost-trunk\libs\context\src\asm\fcontext_x86_64_ms_pe_masm.asm" ...failed Jamfile</C:/Users/Josh/Documents/code/boost-trunk/libs/context/build>.masm64 C:\Users\Josh\Documents\code\boost-trunk\bin.v2\libs\context\build\gcc-mingw-4.7.0\release\address-model-64\architecture-x86\debug-symbols-on\link-static\runtime-link-static\threading-multi\asm\fcontext_x86_64_ms_pe_masm.o... This occurs for both 64-bit and 32-bit compilation. Is this a known issue with a planned fix? Or is MSVC the only compiler supported under Windows? (I know it's a pain because GCC afaik uses a different assembly syntax... Not sure about Intel.) As an aside, Boost.Context does not yet seem to have an entry in Trac. Thanks.

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