June 2013 - Boost - lists.preview.boost.org

Could the custom allocator for flyweight hashed_factory be the boost::interprocess::allocator?
by Jin Chen 25 Jun '13

25 Jun '13

I want to use boost::flyweight to do the dedupilcation of boost::interprocess::basic_string object. I wrote a small test program for that. In my program: The flyweight works fine with the interprocess::basic_string which uses the interprocess::allocator only with the default hashed_factory. The default hashed_factory is ideal except that it uses std::allocator instead of interprocess::allocator. I followed the http://www.boost.org/doc/libs/1_53_0/libs/flyweight/doc/tutorial/configurat… specifier of a custom hash_factory which can change its allocator to the interprocess one, but then got insanely long compiler error that is super hard to decode... Right now, I don't know if only use interprocess::allocator in interprocess::basic_string alone will make the flyweight object be shared by multiple process, guess probably not... Then wonder whether that I didn't use the right syntax for custom hashed_factory or flyweight is compatible with boost::interprocess at all... If it is compatible, what's the right syntax for that? How shall I change my code? Below is a test program attached. The code could compile now with flyweight's default hashed_factory. The goal is to make it compile with ShmStringHashedFactory which use the interprocess allocator.

2 1

Proposal for a thread "collision" detector
by Gaetano Mendola 24 Jun '13

24 Jun '13

I would like to know if Boost community could be interested in adopting a check mechanism that is able to detect if a not supposed thread safe class is used by multiple threads in unsafe way. This tecnique has saved us a lot of headache especially when code refactoring on old code is performed. Better to explain it, without enter in the detail of the implementation, with some examples: Example: Queue implementation non thread-safe but still usable if clients are synchronized somehow. class NonThreadSafeQueue { public: ... void push(int) { DFAKE_SCOPED_LOCK(push_pop_); ... } int pop() { DFAKE_SCOPED_LOCK(push_pop_); ... } ... private: DFAKE_MUTEX(push_pop_); }; Example: Queue implementation not usable even if clients are synchronized, so only one thread in the class life cycle can use the two members push/pop. In this case the macro DFAKE_SCOPED_LOCK_THREAD_LOCKED pins the specified critical section the first time a thread enters push or pop, from that time on only that thread is allowed to execute push or pop. class NonThreadSafeQueue { public: ... void push(int) { DFAKE_SCOPED_LOCK_THREAD_LOCKED(push_pop_); ... } int pop() { DFAKE_SCOPED_LOCK_THREAD_LOCKED(push_pop_); ... } ... private: DFAKE_MUTEX(push_pop_); }; Example: Class that has to be contructed/destroyed on same thread, it has a "shareable" method (with external syncronization) and a not shareable method (even with external synchronization). In this case 3 Critical sections have to be defined class ExoticClass { public: ExoticClass() { DFAKE_SCOPED_LOCK_THREAD_LOCKED(ctor_dtor_); ... } ~ExoticClass() { DFAKE_SCOPED_LOCK_THREAD_LOCKED(ctor_dtor_); ... } void Shareable() { DFAKE_SCOPED_LOCK(shareable_section_); ... } void NotShareable() { DFAKE_SCOPED_LOCK_THREAD_LOCKED(ctor_dtor_); ... } ... private: DFAKE_MUTEX(ctor_dtor_) DFAKE_MUTEX(shareable_section_) }; DFAKE_SCOPED_LOCK will "throw an exception" or will call an "abort" in case of check failed. This tecnique doesn't involve real lock/unlock but uses atomic operations, also the various macros DFAKE_XXXXXXXXX are defined void when NDEBUG is defined. Any comment is appreciated. Regards Gaetano Mendola

3 3

The release branch is CLOSED - except by specific permission
by Marshall Clow 24 Jun '13

24 Jun '13

We're counting down to release next Monday. -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki

1 0

Heads up - Release branch closed as of tomorrow
by Marshall Clow 24 Jun '13

24 Jun '13

Starting tomorrow (Monday, June 27), the release branch will be closed, except by permission from the release managers. -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki

3 5

[smart_ptr] enable_shared_from_this and shared_ptr to a base class
by Adam Romanek 24 Jun '13

24 Jun '13

Hi, I have a question related to using shared_from_this() and a shared_ptr to a base class. Here's a modified version of the enable_shared_from_this usage example from its documentation web page: #include <boost/enable_shared_from_this.hpp> #include <boost/shared_ptr.hpp> #include <cassert> class X { public: virtual void foo() = 0; }; class Y: public X, public boost::enable_shared_from_this<Y> { virtual void foo() { shared_from_this(); } }; int main() { X* x_ptr = new Y; boost::shared_ptr<X> sp(x_ptr); sp->foo(); } First, class Y is now derived from class X. Secondly, shared_ptr's template argument is now X and the parameter to the shared_ptr's constructor is now a pointer to X. Now, calling shared_from_this() in X and/or Y throws boost::bad_weak_ptr. Is this correct behavior? Is it documented somewhere? I know that the example is a bit unrealistic since most of the time shared_ptr is constructed directly from the pointer returned by 'new Y' or created by make_shared() but still, this is something that bothers me. WBR, Adam Romanek

3 9

Boost.Spirit how to use token in functor
by ... ... 24 Jun '13

24 Jun '13

Hi, I have a functor which is working, but its argument, which I don't know its type, I don't know what to do with it. I want to extract data out of it, I want to know is beginning and its end, I want to display the the content of the string character in my consol... but I can't retrieve this information. How could I archieve it ? What is the type of the argument relay to my function ? Is there a dOxygen like documentation (the one on the Boost site is great but a formal documentaton is also interesting). Where is the description and code source of this type ? Here is the code of my functor : struct counter{ counter() : j(0) {j = new int();} counter(const counter &model) : j(model.j) {} template <typename Token> bool operator()(Token const& t){// t is the argument I want to use ++i; ++(*j); std::ostringstream oss; oss << "global : " << i << " membre : " << *j;//typeid(t).name(); printf("%s\n", oss.str().c_str()); return true; } int* j;}; Thanks every one, cordialy,Guillaume Bersac237bis rue de Pessac33000 Bordeaux06.65.30.89.43

2 1

Re: [boost] De Bruijn Bind (alternate bind syntax) Interest?
by Larry Evans 24 Jun '13

24 Jun '13

On 09/02/10 16:08, David Sankel wrote:> 2010/9/2 David Sankel <camior(a)gmail.com> > >> 2010/9/2 Dave Abrahams <dave(a)boostpro.com> >> >> On Thu, Sep 2, 2010 at 11:57 AM, David Sankel <camior(a)gmail.com> wrote: >>> >>>> Hello all, >>>> >>>> I've been working on an alternate bind syntax based on De Bruijn >>>> indices[1]. >>>> The syntax is very simple, yet the terms are very powerful. >>>> >>>> Here is an example of a function const that takes in an argument c and >>>> returns another function that, for all input, returns c: >>>> >>>> //λx.λy.x = λλ1 with De Bruijn indices. >>>> >>> >>> Not according to the page you linked below. What am I missing? >>> >>> [1] http://en.wikipedia.org/wiki/De_Bruijn_index >>> >> >> Sorry about that. The wikipedia page uses 1-indexed indices where I'm using >> 0-indexed indices. So, increment 1 on all my examples to get the wikipedia >> syntax. >> > > I'm beginning to think it is better to use 1-indexing instead of 0-indexing > all around. It will be both compatible with the Wikipedia page and familiar > to boost bind/lambda users. > > Funny thing is, I started with 1-indexing but changed it to 0-indexing for > the fallacious reasoning of the arrrrgh function that Dave A mentioned. > Hi David, I looked at the web page mentioned in your first post to this thread and could not understand the flip example: For flip, I'm introducing subscripts on abstractions (λ) to indicate the number of arguments. For the variables (1,2,etc.) I use a subscript to indicate which argument of the abstraction it refers to. flip = λx.λ(y,z).x(z,y) = λ₁λ₂1(1₁, 2₀) which seems to have a 0 for the subscript of 2. and 1 for the subscript of 1. That's consistent with the argument indices starting at 0 (1₁ corresponds z {the 2nd argument in the argument list, (z,y)}, and 2₀ corresponds to y {the 1st argument in the argument list, (z,y)}); however, subscrited numbers should be the same since both y and z are bound by the same lamba, the nearest one corresponding to number 1. Hence, shouldn't the above be: flip = λx.λ(y,z).x(z,y) = λ₁λ₂2₀(1₁, 1₀) ? Also, since the abstraction indices seem to start at 1, shouldn't the argument indices also start at 1? I think that would make the notation more consistent, and would result in: flip = λx.λ(y,z).x(z,y) = λ₁λ₂2_1(1_2, 1_1) (where a subscript of I have been replaced with _I).

2 1

Error while linking boost. spirit
by ... ... 23 Jun '13

23 Jun '13

Hi, I just downloaded, compiled and install boost.It seems like the installation process worked fine and I successfully compiled a program using boost (boost.log for instance). But when I try to compile an example writed by the developpers of boost.spirit, it fail ! It doesn't seem like it's an inclusion resolution problems, I don't know what to do. Please help me. Here is my code (I paste it from this page) : #include <stdio.h>#include <stdlib.h> #include <boost/spirit/include/lex_lexertl.hpp>#include <boost/spirit/include/phoenix_operator.hpp>#include <boost/spirit/include/phoenix_statement.hpp>#include <boost/spirit/include/phoenix_algorithm.hpp>#include <boost/spirit/include/phoenix_core.hpp>#define BOOST_ALL_DYN_LINK//without it boost.log glitch#include <boost/log/trivial.hpp> int main(){ BOOST_LOG_TRIVIAL(trace) << "boost.log is working !"; typedef lex::lexertl::token<char const*, lex::omit, boost::mpl::false_> token_type; typedef lex::lexertl::actor_lexer<token_type> lexer_type; word_count_tokens<lexer_type> word_count_lexer; std::string str (read_from_file("mainwindow.cpp.txt")); char const* first = str.c_str(); char const* last = &first[str.size()]; lexer_type::iterator_type iter = word_count_lexer.begin(first, last); lexer_type::iterator_type end = word_count_lexer.end(); while (iter != end && token_is_valid(*iter)) ++iter; if (iter == end) { std::cout << "lines: " << word_count_lexer.l << ", words: " << word_count_lexer.w << ", characters: " << word_count_lexer.c << "\n"; } else { std::string rest(first, last); std::cout << "Lexical analysis failed\n" << "stopped at: \"" << rest << "\"\n"; } return 0; }} And here is my error log : 11:32:39 **** Incremental Build of configuration Default for project synthax_analyser ****make all g++ -O2 -g -Wall -fmessage-length=0 -c -o synthax_analyser.o synthax_analyser.cppsynthax_analyser.cpp: In function ‘int main()’:synthax_analyser.cpp:24:4: error: ‘lex’ does not name a typesynthax_analyser.cpp:27:10: error: ‘lex’ does not name a typesynthax_analyser.cpp:29:2: error: ‘word_count_tokens’ was not declared in this scopesynthax_analyser.cpp:29:20: error: ‘lexer_type’ was not declared in this scopesynthax_analyser.cpp:29:20: note: suggested alternative:In file included from /usr/local/include/boost/spirit/home/lex/meta_compiler.hpp:16:0, from /usr/local/include/boost/spirit/home/lex/reference.hpp:14, from /usr/local/include/boost/spirit/home/lex/lexer/token_def.hpp:21, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:14, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/spirit/home/lex/lexer_type.hpp:20:12: note: ‘boost::spirit::lex::lexer_type’synthax_analyser.cpp:29:32: error: ‘word_count_lexer’ was not declared in this scopesynthax_analyser.cpp:31:54: error: ‘read_from_file’ was not declared in this scopesynthax_analyser.cpp:35:2: error: ‘lexer_type’ is not a class or namespacesynthax_analyser.cpp:35:28: error: expected ‘;’ before ‘iter’synthax_analyser.cpp:36:3: error: ‘lexer_type’ is not a class or namespacesynthax_analyser.cpp:36:29: error: expected ‘;’ before ‘end’synthax_analyser.cpp:38:9: error: ‘iter’ was not declared in this scopesynthax_analyser.cpp:38:17: error: ‘end’ was not declared in this scopesynthax_analyser.cpp:38:17: note: suggested alternatives:In file included from /usr/local/include/boost/range/empty.hpp:20:0, from /usr/local/include/boost/proto/functional/range/empty.hpp:12, from /usr/local/include/boost/proto/functional/range.hpp:13, from /usr/local/include/boost/proto/functional.hpp:14, from /usr/local/include/boost/proto/proto.hpp:16, from /usr/local/include/boost/spirit/home/support/terminal.hpp:18, from /usr/local/include/boost/spirit/home/support/common_terminals.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/terminals.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:13, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/range/end.hpp:106:61: note: ‘boost::range_adl_barrier::end’In file included from /usr/local/include/boost/fusion/container/list/cons.hpp:14:0, from /usr/local/include/boost/fusion/iterator/segmented_iterator.hpp:13, from /usr/local/include/boost/fusion/sequence/intrinsic/detail/segmented_begin.hpp:11, from /usr/local/include/boost/fusion/sequence/intrinsic/begin.hpp:17, from /usr/local/include/boost/fusion/container/vector/vector10.hpp:15, from /usr/local/include/boost/fusion/container/vector.hpp:12, from /usr/local/include/boost/fusion/include/vector.hpp:10, from /usr/local/include/boost/spirit/home/phoenix/core/limits.hpp:73, from /usr/local/include/boost/spirit/home/phoenix/core.hpp:11, from /usr/local/include/boost/spirit/include/phoenix_core.hpp:14, from /usr/local/include/boost/spirit/home/support/terminal.hpp:16, from /usr/local/include/boost/spirit/home/support/common_terminals.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/terminals.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:13, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/fusion/sequence/intrinsic/end.hpp:89:5: note: ‘boost::fusion::end’In file included from /usr/local/include/boost/fusion/sequence/intrinsic/begin.hpp:13:0, from /usr/local/include/boost/fusion/container/vector/vector10.hpp:15, from /usr/local/include/boost/fusion/container/vector.hpp:12, from /usr/local/include/boost/fusion/include/vector.hpp:10, from /usr/local/include/boost/spirit/home/phoenix/core/limits.hpp:73, from /usr/local/include/boost/spirit/home/phoenix/core.hpp:11, from /usr/local/include/boost/spirit/include/phoenix_core.hpp:14, from /usr/local/include/boost/spirit/home/support/terminal.hpp:16, from /usr/local/include/boost/spirit/home/support/common_terminals.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/terminals.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:13, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/fusion/sequence/intrinsic_fwd.hpp:67:16: note: ‘boost::fusion::result_of::end’In file included from /usr/local/include/boost/fusion/support/sequence_base.hpp:11:0, from /usr/local/include/boost/fusion/container/vector/vector10.hpp:11, from /usr/local/include/boost/fusion/container/vector.hpp:12, from /usr/local/include/boost/fusion/include/vector.hpp:10, from /usr/local/include/boost/spirit/home/phoenix/core/limits.hpp:73, from /usr/local/include/boost/spirit/home/phoenix/core.hpp:11, from /usr/local/include/boost/spirit/include/phoenix_core.hpp:14, from /usr/local/include/boost/spirit/home/support/terminal.hpp:16, from /usr/local/include/boost/spirit/home/support/common_terminals.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/terminals.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:13, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/mpl/begin_end_fwd.hpp:23:38: note: ‘boost::mpl::end’In file included from /usr/local/include/boost/proto/functional/range.hpp:14:0, from /usr/local/include/boost/proto/functional.hpp:14, from /usr/local/include/boost/proto/proto.hpp:16, from /usr/local/include/boost/spirit/home/support/terminal.hpp:18, from /usr/local/include/boost/spirit/home/support/common_terminals.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/terminals.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:13, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/proto/functional/range/end.hpp:19:12: note: ‘boost::proto::functional::end’In file included from /usr/local/include/boost/range/empty.hpp:20:0, from /usr/local/include/boost/proto/functional/range/empty.hpp:12, from /usr/local/include/boost/proto/functional/range.hpp:13, from /usr/local/include/boost/proto/functional.hpp:14, from /usr/local/include/boost/proto/proto.hpp:16, from /usr/local/include/boost/spirit/home/support/terminal.hpp:18, from /usr/local/include/boost/spirit/home/support/common_terminals.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/terminals.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:13, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/range/end.hpp:106:61: note: ‘boost::range_adl_barrier::end’In file included from /usr/local/include/boost/spirit/home/support/string_traits.hpp:16:0, from /usr/local/include/boost/spirit/home/support/nonterminal/expand_arg.hpp:20, from /usr/local/include/boost/spirit/home/support/context.hpp:18, from /usr/local/include/boost/spirit/home/qi/domain.hpp:18, from /usr/local/include/boost/spirit/home/qi/parser.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/token_def.hpp:17, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:14, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/spirit/home/support/container.hpp:445:5: note: ‘boost::spirit::traits::end’In file included from /usr/local/include/boost/spirit/home/support/handles_container.hpp:14:0, from /usr/local/include/boost/spirit/home/lex/lexer/token_def.hpp:16, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:14, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/spirit/home/support/attributes_fwd.hpp:43:12: note: ‘boost::spirit::result_of::end’In file included from /usr/local/include/boost/spirit/home/support/info.hpp:17:0, from /usr/local/include/boost/spirit/home/lex/lexer/token_def.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:14, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/foreach.hpp:730:1: note: ‘boost::foreach_detail_::end’synthax_analyser.cpp:38:44: error: ‘token_is_valid’ was not declared in this scopesynthax_analyser.cpp:38:44: note: suggested alternatives:In file included from /usr/local/include/boost/spirit/home/lex/lexer/lexertl/lexer.hpp:20:0, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:16, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/spirit/home/lex/lexer/lexertl/token.hpp:415:5: note: ‘boost::spirit::lex::lexertl::token_is_valid’In file included from /usr/local/include/boost/spirit/home/lex/lexer/lexertl/iterator.hpp:18:0, from /usr/local/include/boost/spirit/home/lex/lexer/lexertl/lexer.hpp:23, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:16, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/spirit/home/support/iterators/detail/split_functor_input_policy.hpp:19:21: note: ‘boost::spirit::iterator_policies::split_functor_input_is_valid_test_::token_is_valid’synthax_analyser.cpp:41:7: error: ‘iter’ was not declared in this scopesynthax_analyser.cpp:41:15: error: ‘end’ was not declared in this scopesynthax_analyser.cpp:41:15: note: suggested alternatives:In file included from /usr/local/include/boost/range/empty.hpp:20:0, from /usr/local/include/boost/proto/functional/range/empty.hpp:12, from /usr/local/include/boost/proto/functional/range.hpp:13, from /usr/local/include/boost/proto/functional.hpp:14, from /usr/local/include/boost/proto/proto.hpp:16, from /usr/local/include/boost/spirit/home/support/terminal.hpp:18, from /usr/local/include/boost/spirit/home/support/common_terminals.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/terminals.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:13, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/range/end.hpp:106:61: note: ‘boost::range_adl_barrier::end’In file included from /usr/local/include/boost/fusion/container/list/cons.hpp:14:0, from /usr/local/include/boost/fusion/iterator/segmented_iterator.hpp:13, from /usr/local/include/boost/fusion/sequence/intrinsic/detail/segmented_begin.hpp:11, from /usr/local/include/boost/fusion/sequence/intrinsic/begin.hpp:17, from /usr/local/include/boost/fusion/container/vector/vector10.hpp:15, from /usr/local/include/boost/fusion/container/vector.hpp:12, from /usr/local/include/boost/fusion/include/vector.hpp:10, from /usr/local/include/boost/spirit/home/phoenix/core/limits.hpp:73, from /usr/local/include/boost/spirit/home/phoenix/core.hpp:11, from /usr/local/include/boost/spirit/include/phoenix_core.hpp:14, from /usr/local/include/boost/spirit/home/support/terminal.hpp:16, from /usr/local/include/boost/spirit/home/support/common_terminals.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/terminals.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:13, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/fusion/sequence/intrinsic/end.hpp:89:5: note: ‘boost::fusion::end’In file included from /usr/local/include/boost/fusion/sequence/intrinsic/begin.hpp:13:0, from /usr/local/include/boost/fusion/container/vector/vector10.hpp:15, from /usr/local/include/boost/fusion/container/vector.hpp:12, from /usr/local/include/boost/fusion/include/vector.hpp:10, from /usr/local/include/boost/spirit/home/phoenix/core/limits.hpp:73, from /usr/local/include/boost/spirit/home/phoenix/core.hpp:11, from /usr/local/include/boost/spirit/include/phoenix_core.hpp:14, from /usr/local/include/boost/spirit/home/support/terminal.hpp:16, from /usr/local/include/boost/spirit/home/support/common_terminals.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/terminals.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:13, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/fusion/sequence/intrinsic_fwd.hpp:67:16: note: ‘boost::fusion::result_of::end’In file included from /usr/local/include/boost/fusion/support/sequence_base.hpp:11:0, from /usr/local/include/boost/fusion/container/vector/vector10.hpp:11, from /usr/local/include/boost/fusion/container/vector.hpp:12, from /usr/local/include/boost/fusion/include/vector.hpp:10, from /usr/local/include/boost/spirit/home/phoenix/core/limits.hpp:73, from /usr/local/include/boost/spirit/home/phoenix/core.hpp:11, from /usr/local/include/boost/spirit/include/phoenix_core.hpp:14, from /usr/local/include/boost/spirit/home/support/terminal.hpp:16, from /usr/local/include/boost/spirit/home/support/common_terminals.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/terminals.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:13, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/mpl/begin_end_fwd.hpp:23:38: note: ‘boost::mpl::end’In file included from /usr/local/include/boost/proto/functional/range.hpp:14:0, from /usr/local/include/boost/proto/functional.hpp:14, from /usr/local/include/boost/proto/proto.hpp:16, from /usr/local/include/boost/spirit/home/support/terminal.hpp:18, from /usr/local/include/boost/spirit/home/support/common_terminals.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/terminals.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:13, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/proto/functional/range/end.hpp:19:12: note: ‘boost::proto::functional::end’In file included from /usr/local/include/boost/range/empty.hpp:20:0, from /usr/local/include/boost/proto/functional/range/empty.hpp:12, from /usr/local/include/boost/proto/functional/range.hpp:13, from /usr/local/include/boost/proto/functional.hpp:14, from /usr/local/include/boost/proto/proto.hpp:16, from /usr/local/include/boost/spirit/home/support/terminal.hpp:18, from /usr/local/include/boost/spirit/home/support/common_terminals.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/terminals.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:13, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/range/end.hpp:106:61: note: ‘boost::range_adl_barrier::end’In file included from /usr/local/include/boost/spirit/home/support/string_traits.hpp:16:0, from /usr/local/include/boost/spirit/home/support/nonterminal/expand_arg.hpp:20, from /usr/local/include/boost/spirit/home/support/context.hpp:18, from /usr/local/include/boost/spirit/home/qi/domain.hpp:18, from /usr/local/include/boost/spirit/home/qi/parser.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer/token_def.hpp:17, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:14, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/spirit/home/support/container.hpp:445:5: note: ‘boost::spirit::traits::end’In file included from /usr/local/include/boost/spirit/home/support/handles_container.hpp:14:0, from /usr/local/include/boost/spirit/home/lex/lexer/token_def.hpp:16, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:14, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/spirit/home/support/attributes_fwd.hpp:43:12: note: ‘boost::spirit::result_of::end’In file included from /usr/local/include/boost/spirit/home/support/info.hpp:17:0, from /usr/local/include/boost/spirit/home/lex/lexer/token_def.hpp:15, from /usr/local/include/boost/spirit/home/lex/lexer.hpp:14, from /usr/local/include/boost/spirit/home/lex.hpp:13, from /usr/local/include/boost/spirit/home/lex/lexer_lexertl.hpp:15, from /usr/local/include/boost/spirit/include/lex_lexertl.hpp:16, from synthax_analyser.cpp:12:/usr/local/include/boost/foreach.hpp:730:1: note: ‘boost::foreach_detail_::end’synthax_analyser.cpp: At global scope:synthax_analyser.cpp:54:1: error: expected declaration before ‘}’ tokenmake: *** [synthax_analyser.o] Error 1 Cordialy,Guillaume Bersac237bis rue de Pessac33000 Bordeaux06.65.30.89.43

5 5

concurrent garbage collector
by Taylor Holliday 23 Jun '13

23 Jun '13

Hey Boost, After struggling with breaking shared_ptr cycles in my app, I wrote a little concurrent garbage collector which uses boost::lockfree::queue. Its actually fairly general purpose, and I've released the code here: https://gist.github.com/wtholliday/5793270 Inspired by my question on stack overflow: http://stackoverflow.com/questions/17116189/concurrent-garbage-collection-f… I'm also working on releasing my unit test... its just quite dependent on other code. For the interface: the basic idea is you have a RootPtr<T> used to manage the collector's root set (please forgive my propensity for CamelCase). You have to explicitly manage references between collectable objects (via AddEdge and RemoveEdge functions), but I think that could be made safe using another smart pointer type which knows the collectable object which owns it. At this point I'm not too concerned about performance, as my object graphs aren't that big. I bet a GC guru could implement this without using a queue of events. Anyway, this is the kind of thing I'd love to see in boost someday, so it would be great to read your opinions of it :-) cheers - Taylor W. Taylor Holliday, Owner/Founder Subatomic Software, San Francisco

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Re: [boost] [Multiprecision] Does MP use references internally?
by Daryle Walker 21 Jun '13

21 Jun '13

Nearly all operators, besides assigning and dereferencing ones, are supposed to return by value. Changing that, even with the “innocuous” (unary)+, is surprising. Daryle W. Sent from Windows Mail From: John Maddock Sent: ‎Thursday‎, ‎June‎ ‎20‎, ‎2013 ‎4‎:‎13‎ ‎AM To: boost(a)lists.boost.org > Is Boost.MP giving users references-to-types instead of class types when > requesting a numeric type? Pointers may be objects in and of themselves, > but references aren't; they're just aliases; trying to intentionally use > them as first-class objects is arguably broken. I don't see why this is a problem, but the first error is coming from: auto const aa = +a, bb = +b; Now, in Boost.Multiprecision the unary operator+ is a noop that returns a reference to self, could that be a cause of the issue?

4 3