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[Boost.Thread] Compile error: boost::promise<T>::set_value(const T&) doesn't exist
by Rob Desbois 10 Aug '14

10 Aug '14

Hi all, I'm having problems compiling with Boost.Thread's futures I can't seem to pass anything but a primitive type into make_ready_future. I've had problems with other parts of Thread (packaged_task, promise, unique/shared_future) that have produced horrendously unhelpful compile errors. Here is a minimal testcase: #include <boost/thread/future.hpp> struct foo { foo(int i_): i(i_) {} int i; }; int main() { // A const future ref isn't much use, but I needed to prove // the problem wasn't me trying to copy a unique_future const boost::unique_future<foo>& fut = boost::make_ready_future( foo(42) ); } With `BOOST_THREAD_USES_MOVE` defined before including the Boost.Future header I get the following error with gcc 4.8.2 and Boost 1.55 (full output at http://pastebin.com/0sePWBWr) ../../deps/boost/include/boost/thread/future.hpp:3634:5: error: no matching function for call to ‘boost::promise<foo>::set_value(const foo&)’ p.set_value(boost::forward<future_value_type>(value)); ^ There seems to be no overload of promise::set_value() that takes a const lvalue reference. Looking at `promise` and `future_traits` in `future.hpp` it seems that the const lvalue ref overload will only exist when `BOOST_NO_CXX11_RVALUE_REFERENCES` is undefined. That makes no sense to me however...surely the const lvalue ref overload is needed precisely when there are no rvalue references? (Note this happens even if I pass a mutable lvalue ref to `make_ready_future()`). If I don't define `BOOST_THREAD_USES_MOVE` it fails compilation with the following error (full output at http://pastebin.com/jBwiJLeC) ../../deps/boost/include/boost/thread/detail/move.hpp:183:54: error: no matching function for call to boost::unique_future<foo>::unique_future(boost::unique_future<foo>)’ #define BOOST_THREAD_MAKE_RV_REF(RVALUE) RVALUE.move() ^ Have I missed something? I'm unable to switch to C++11 mode unfortunately, but this seems such a big problem I can only assume I've done something wrong. I still get similar compile errors trying with Clang 3.4, and also with Boost 1.54 (g++ or Clang). -- Rob Desbois http://theotherbranch.wordpress.com/

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[Boost.Range] Filtering elements at even position
by Arindam Mukherjee 10 Aug '14

10 Aug '14

I am trying to create a range consisting of elements in a container at only even indexes. Is there a way to write something like: vec | boost::adaptors::indexed(0) | some_adaptor_to_choose_even_indexes I tried with boost::adaptors::filtered, but the index information is only present in iterators of the generated range, not in its value_type so it is not available in chained adaptors. - Arindam

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Boost 1.56.0 compilation error in iterator_range
by gast128 10 Aug '14

10 Aug '14

I get a compilation error with vc10, iterator_range and a (const) unordered_map (the beta candidate 2 was still ok I think): #include "stdafx.h" #include <boost/range/iterator_range.hpp> #include <boost/unordered_map.hpp> int _tmain(int /*argc*/, _TCHAR* /*argv*/[]) { typedef boost::unordered_map<int, int> Container; typedef Container::const_iterator ContainerIterator; typedef boost::iterator_range<ContainerIterator> ContainerIteratorRange; const Container cnt; ContainerIteratorRange rng(cnt.cbegin(), cnt.cend()); return 0; } This gives C2248: 'boost::unordered::iterator_detail::c_iterator<Node,ConstNodePointer>::iterator' cannot access private typedef declared in class etc. (note had to cut due to 'you have lines longer than 80 characters. Fix that.' in Gmane)

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[boost] [1.55] numerous warnings with gcc 4.8.3 on Linux
by Marius Lazer 08 Aug '14

08 Aug '14

All the warnings are similar to this (warning: typedef âboost_concept_check185â locally defined but not used [-Wunused-local-typedefs]): ./boost/range/algorithm/equal.hpp: In function âbool boost::range::equal(const SinglePassRange1&, const SinglePassRange2&, BinaryPredicate)â: ./boost/concept/detail/general.hpp:71:20: warning: typedef âboost_concept_check185â locally defined but not used [-Wunused-local-typedefs] BOOST_PP_CAT(boost_concept_check,__LINE__) ^ ./boost/preprocessor/cat.hpp:29:34: note: in definition of macro âBOOST_PP_CAT_Iâ # define BOOST_PP_CAT_I(a, b) a ## b ^ ./boost/concept/detail/general.hpp:71:7: note: in expansion of macro âBOOST_PP_CATâ BOOST_PP_CAT(boost_concept_check,__LINE__) ^ ./boost/concept/assert.hpp:44:5: note: in expansion of macro âBOOST_CONCEPT_ASSERT_FNâ BOOST_CONCEPT_ASSERT_FN(void(*)ModelInParens) ^ ./boost/range/concepts.hpp:92:45: note: in expansion of macro âBOOST_CONCEPT_ASSERTâ #define BOOST_RANGE_CONCEPT_ASSERT( x ) BOOST_CONCEPT_ASSERT( x ) ^ ./boost/range/algorithm/equal.hpp:185:13: note: in expansion of macro âBOOST_RANGE_CONCEPT_ASSERTâ BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<const SinglePassRange1> )); ^ ./boost/concept/detail/general.hpp:71:20: warning: typedef âboost_concept_check186â locally defined but not used [-Wunused-local-typedefs] BOOST_PP_CAT(boost_concept_check,__LINE__) ^ ./boost/preprocessor/cat.hpp:29:34: note: in definition of macro âBOOST_PP_CAT_Iâ # define BOOST_PP_CAT_I(a, b) a ## b ./boost/concept/detail/general.hpp:71:7: note: in expansion of macro âBOOST_PP_CATâ BOOST_PP_CAT(boost_concept_check,__LINE__) ^ ./boost/concept/assert.hpp:44:5: note: in expansion of macro âBOOST_CONCEPT_ASSERT_FNâ BOOST_CONCEPT_ASSERT_FN(void(*)ModelInParens) ^ ./boost/range/concepts.hpp:92:45: note: in expansion of macro âBOOST_CONCEPT_ASSERTâ #define BOOST_RANGE_CONCEPT_ASSERT( x ) BOOST_CONCEPT_ASSERT( x ) ^ ./boost/range/algorithm/equal.hpp:186:13: note: in expansion of macro âBOOST_RANGE_CONCEPT_ASSERTâ BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<const SinglePassRange2> )); Thanks, Marius Marius S. Lazer ICAP North America Inc. Harborside Financial Center 1100 Plaza 5 Jersey City, NJ 07311-4996 Office: 212-815-7470 Email: Marius.Lazer(a)us.icap.com ********************************************************************** This communication and all or some of the information contained therein may be confidential and is subject to our Terms and Conditions. If you have received this communication in error, please destroy all electronic and paper copies and notify the sender immediately. Unless specifically indicated, this communication is not a confirmation, an offer to sell or solicitation of any offer to buy any financial product, or an official statement of ICAP or its affiliates. Non-Transactable Pricing Terms and Conditions apply to any non-transactable pricing provided. All terms and conditions referenced herein available at www.icapterms.com. Please notify us by reply message if this link does not work. ********************************************************************** ICAP's 21st global annual Charity Day – took place Tuesday 3 December 2013. Together we raised £9.5 million (US$15.5 million), totalling £110 million since 1993. www.icapcharityday.com --------------------------------------------------------------------------------------- This email has been scanned for email related threats and delivered safely by Mimecast. For more information please visit http://www.mimecast.com ---------------------------------------------------------------------------------------

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BOOST_STRONG_TYPEDEF
by Jono Poff 08 Aug '14

08 Aug '14

Hi, compiling this program with g++ 4.7.1 ... #include <boost/serialization/strong_typedef.hpp> BOOST_STRONG_TYPEDEF(uint32_t, LINKID_T) int main() { LINKID_T lid = 0xffddee33; return 0; } I get error: conversion from 'unsigned int' to non-scalar type 'LINKID_T' requested Looking at the header, the strong typedef struct defines assignment from uint32_t to LINKID_T ... D & operator=(const T & rhs) { t = rhs; return *this;} ... so what gives? Cheers, Jono -- ------------------------------ This email, including any attachments, is only for the intended recipient. It is subject to copyright, is confidential and may be the subject of legal or other privilege, none of which is waived or lost by reason of this transmission. If you are not an intended recipient, you may not use, disseminate, distribute or reproduce such email, any attachments, or any part thereof. If you have received a message in error, please notify the sender immediately and erase all copies of the message and any attachments. Unfortunately, we cannot warrant that the email has not been altered or corrupted during transmission nor can we guarantee that any email or any attachments are free from computer viruses or other conditions which may damage or interfere with recipient data, hardware or software. The recipient relies upon its own procedures and assumes all risk of use and of opening any attachments. ------------------------------

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BOOST_STRONG_TYPEDEF ...ps
by Jono Poff 08 Aug '14

08 Aug '14

Sorry, forgot to say Boost 1.55.0 Jono -- ------------------------------ This email, including any attachments, is only for the intended recipient. It is subject to copyright, is confidential and may be the subject of legal or other privilege, none of which is waived or lost by reason of this transmission. If you are not an intended recipient, you may not use, disseminate, distribute or reproduce such email, any attachments, or any part thereof. If you have received a message in error, please notify the sender immediately and erase all copies of the message and any attachments. Unfortunately, we cannot warrant that the email has not been altered or corrupted during transmission nor can we guarantee that any email or any attachments are free from computer viruses or other conditions which may damage or interfere with recipient data, hardware or software. The recipient relies upon its own procedures and assumes all risk of use and of opening any attachments. ------------------------------

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Geometry layout (packing) algorithm?
by Belcourt, Kenneth 07 Aug '14

07 Aug '14

Hi, I’m looking for an algorithm that will take a largish number (i.e. 10^5) 2d or 3d polygons (mostly parallel-pipeds, e.g. squares and boxes) and partition them into non-overlapping groups where each group contains some number of polygons that might abut along an edge or face, but not overlap. Each box can be represented by a collection of line segments so I thought geometry might have what I’m looking for but I didn’t see anything in a quick scan of the documentation. Does this so called packing (layout) algorithm sound like something already in Boost, Geometry or other library? I have an implementation but what looking to see what other options exist. Thanks. — Noel Belcourt

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[boost] [1.56.0] Release Candidate 3 available
by Marshall Clow 07 Aug '14

07 Aug '14

We've created a third release candidate to fix a one more issue with Boost.Range. The files for 1.56.0 RC3 are available at: http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. The files (and associated md5s) are: MD5 (./boost_1_56_0_rc3.7z) = b7a72a6a6f487fa445333b4e115c6171 MD5 (./boost_1_56_0_rc3.tar.bz2) = a744cf167b05d72335f27c88115f211d MD5 (./boost_1_56_0_rc3.tar.gz) = 8c54705c424513fa2be0042696a3a162 MD5 (./boost_1_56_0_rc3.zip) = fc16da21d641e03715a4144cb093964e Thanks! -- The release managers

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[date-time] boost::time_duration wrapping
by Justin Muncaster 07 Aug '14

07 Aug '14

Hello, I’m having issues with wrapping of boost::time_duration derived types. I can’t find anywhere in the documentation for when the time_duration types are supposed to wrap around. I have attached some sample source code below. The output is: SecCount = 80000000 is OK. Strange Stranger Problematic SecCount = 80000001 is STRANGE. I expect the output to be SecCount = 80000000 is OK. SecCount = 80000001 is OK. The problem we ran into had to do with seconds and milliseconds having different maximum permissible values. Any idea why boost::posix_time::seconds goes negative at 0x80000001 while milliseconds is not until much later? Thanks, Justin // // test.cpp // #include <boost/date_time.hpp> #include <iostream> using namespace std; using namespace boost::posix_time; //------------------------------------------------------- //------------------------------------------------------- void Strange(long SecCount) { long MilliCount = 1000 * SecCount; bool IsStrange = false; if (SecCount >= 0 && seconds(SecCount).is_negative()) { cout << "Strange" << endl; IsStrange = true; if (!milliseconds(MilliCount).is_negative()) { // If seconds wraps, why doesn't milliseconds? cout << "Stranger" << endl; IsStrange = true; } } if (seconds(SecCount) != milliseconds(MilliCount)) { cout << "Problematic" << endl; IsStrange = true; } if (!IsStrange) { cout << "SecCount = " << SecCount << " is OK." << endl; } else { cout << "SecCount = " << SecCount << " is STRANGE." << endl; } } //------------------------------------------------------- //------------------------------------------------------- int main() { cout << hex; Strange(0x80000000); Strange(0x80000001); return 0; }

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Re: [Boost-users] [ASIO] directory monitor ASIO extension
by Brian Wood 06 Aug '14

06 Aug '14

Niall Douglas writes > * Works reliably on Microsoft Windows (hard), Linux (slightly > easier), BSD and OS X (easiest by far of the lot). > I believe you. Having considered some of your previous comments in a different thread, on kqueue, I ported my code generator from Linux to BSD. I only found relief from a problem I was having by doing so. > Paul Kirth presented on this at C++ Now 2014. It is a surprisingly > tough engineering problem, and requires a design approaching ideal > for it to work at all. Are videos from that conference available yet? -- Brian Ebenezer Enterprises - In G-d we trust. http://webEbenezer.net

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