April 2013 - Boost-users - lists.preview.boost.org

Redefining new, to detect memory leaks, causes issues in boost
by Lasse Laursen 10 May '13

10 May '13

Hellos, I recently upgraded to vs2012 and am making liberal use of its leak detection described here: http://msdn.microsoft.com/en-us/library/x98tx3cf.aspx However, I'm running into a spot of trouble. I rely on the C++ style new commands to allocate memory and as such, I make use of redefining this call in order to get a specific file and line, at the end of my programs execution, to where I allocated memory which is leaking. It's super effective! According to the link above, the new command is to be redefined thusly: #ifdef _DEBUG #ifndef DBG_NEW #define DBG_NEW new ( _NORMAL_BLOCK , __FILE__ , __LINE__ ) #define new DBG_NEW #endif #endif // _DEBUG However, boost no likey. I get a syntax error in 'initializer.hpp' at the following line (122) of code: new(dest) value_T( boost::detail::variant::move(operand) ); ... saying it no longer knows what 'dest' is. A bit puzzling to be honest. I'm no C++ artisan, so I'm a bit stumped as to how I should elegantly avoid this issue. I really don't need boost to use this redefined new, as I'm sure it's as leak proof as can be, but I'm not sure if it's possible to somehow define my way out of that jam? Or perhaps change the definition so that the line no longer results in a syntax error. Any ideas? Regards, Lasse

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[Intrusive] Obtaining end iterator from value reference
by Andrea Cuneo 01 May '13

01 May '13

Hi all, is it possible with boost::intrusive::slist to obtain the end() iterator from a value object present in a list? Using s_iterator_to() I can obtain a valid iterator from a value reference but i can't forward iterate from it without knowing the end(). Reading the slist code I found the method slist_iterator::get_container but since is a detail implementation, I prefer not to use it. I also found that a default construct iterator is almost equivalent to end() for linear slists and should work just fine. For circular slists? // snipped struct dummy : public slist_base_hook<> {}; typedef slist<dummy> MyList; void fn(dummy const& o) { MyList::const_iterator it = MyList::s_iterator_to(o); MyList::const_iterator e = ???; for (; it != e; ++it) { ... } } Regards, Andrea

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New book by Christopher Kormanyos added to bibliography
by Paul A. Bristow 30 Apr '13

30 Apr '13

I have added a new book by Christopher Kormanyos to the bibliography section at http://www.boost.org/users/bibliography.html Christopher Kormanyos, Real-Time C++: Efficient Object-Oriented and Template Microcontroller Programming. http://www.springer.com/computer/communication+networks/book/978-3-642-3468… Uses C++11 including lambdas, templates, metatemplate programming for efficient programming for microcontrollers including use of Boost.Math, Boost.Regex, Boost.Multiprecision and other Boost libraries. I am sure that many Boosters will find this book interesting, even if they are not into Microcontrollers, because it makes interestingly full use of C++11 to do as much as possible at compile time. This is what everyone wants - not just for microcontrollers. Paul PS I noted during checking that: 1 We are not keeping this section up to date - tell me if you have any recent books that ought to be listed here. 2 I noted during validation of the hand-edited html that there were warnings about invalid attribute 'name'. This should be 'data-name' to be HTML5 compliant. Should I change all these occurrences? --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow(a)hetp.u-net.com

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[phoenix] - std::for_each - How to call member variable that is a boost::function?
by Aaron_Wright＠selinc.com 30 Apr '13

30 Apr '13

I'm a little confused on the correct way to lazily call a boost::function in a phoenix expression. For example, this doesn't do anything: namespace bp = boost::phoenix; namespace bpa = bp::arg_names; struct Foo { boost::function< void() > callback; Foo(boost::function< void() > const& callback) : callback(callback) { } }; main() { std::list< Foo > foos; foos.push_back(Foo(std::cout << bp::val(1) << '\n')); foos.push_back(Foo(std::cout << bp::val(2) << '\n')); foos.push_back(Foo(std::cout << bp::val(3) << '\n')); std::for_each( foos.begin(), foos.end(), bp::bind(&Foo::callback, bpa::arg1)); } If I wrap the bind(...) in another bind(...) it'll work, but is that the right way? I'm not binding anything, I just want the callback called. --- Aaron Wright

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[Process] State of this library
by Armand Leclercq 30 Apr '13

30 Apr '13

Good afternoon, I was looking for a C++ library that would allow me to easily create a sub-process. I was surprised to found one in the boost sandbox, sleeping for some years now. What is missing in this library to be made public ? Is there any maintainer left ? Thanks for you attention -- Armand Leclercq EPITA 2013 Assistant C/Unix

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Errors compiling Boost.Log on OS X
by Rich E 30 Apr '13

30 Apr '13

Hi all, I'm trying to build the recently-added-to-trunk Boost.Log on OS X and smacking into an error when it includes unsupported.cpp. I've google'd around a bit and seen from the macports guys that Boost.Context doesn't currently build for 32-bit architecture, but I can't even get it to build for just 64-bit. Has anyone had success yet with Boost.Log on OS X, or has some insight into how to get this working before it makes it into 1.54? Building with clang against libc++ / C++11, here is the error: clang-darwin.compile.c++ bin.v2/libs/atomic/build/clang-darwin-osx/release/link-static/threading-multi/lockpool.o "xcrun" "clang" "-stdlib=libc++" "-std=c++11" -x c++ -O3 -O3 -finline-functions -Wno-inline -Wall -DBOOST_ALL_NO_LIB=1 -DBOOST_ATOMIC_SOURCE -DNDEBUG -I"." -c -o "bin.v2/libs/atomic/build/clang-darwin-osx/release/link-static/threading-multi/lockpool.o" "libs/atomic/src/lockpool.cpp" RmTemps bin.v2/libs/atomic/build/clang-darwin-osx/release/link-static/threading-multi/libboost_atomic.a(clean) rm -f "bin.v2/libs/atomic/build/clang-darwin-osx/release/link-static/threading-multi/libboost_atomic.a" clang-darwin.archive bin.v2/libs/atomic/build/clang-darwin-osx/release/link-static/threading-multi/libboost_atomic.a "ar" rc "bin.v2/libs/atomic/build/clang-darwin-osx/release/link-static/threading-multi/libboost_atomic.a" "bin.v2/libs/atomic/build/clang-darwin-osx/release/link-static/threading-multi/lockpool.o" "ranlib" -cs "bin.v2/libs/atomic/build/clang-darwin-osx/release/link-static/threading-multi/libboost_atomic.a" common.copy stage/lib/libboost_atomic.a cp "bin.v2/libs/atomic/build/clang-darwin-osx/release/link-static/threading-multi/libboost_atomic.a" "stage/lib/libboost_atomic.a" clang-darwin.compile.c++ bin.v2/libs/system/build/clang-darwin-osx/release/link-static/threading-multi/error_code.o "xcrun" "clang" "-stdlib=libc++" "-std=c++11" -x c++ -O3 -O3 -finline-functions -Wno-inline -Wall -pedantic -DBOOST_ALL_NO_LIB=1 -DBOOST_SYSTEM_STATIC_LINK=1 -DNDEBUG -I"." -c -o "bin.v2/libs/system/build/clang-darwin-osx/release/link-static/threading-multi/error_code.o" "libs/system/src/error_code.cpp" RmTemps bin.v2/libs/system/build/clang-darwin-osx/release/link-static/threading-multi/libboost_system.a(clean) rm -f "bin.v2/libs/system/build/clang-darwin-osx/release/link-static/threading-multi/libboost_system.a" clang-darwin.archive bin.v2/libs/system/build/clang-darwin-osx/release/link-static/threading-multi/libboost_system.a "ar" rc "bin.v2/libs/system/build/clang-darwin-osx/release/link-static/threading-multi/libboost_system.a" "bin.v2/libs/system/build/clang-darwin-osx/release/link-static/threading-multi/error_code.o" "ranlib" -cs "bin.v2/libs/system/build/clang-darwin-osx/release/link-static/threading-multi/libboost_system.a" common.copy stage/lib/libboost_system.a cp "bin.v2/libs/system/build/clang-darwin-osx/release/link-static/threading-multi/libboost_system.a" "stage/lib/libboost_system.a" clang-darwin.compile.c++ bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/chrono.o "xcrun" "clang" "-stdlib=libc++" "-std=c++11" -x c++ -O3 -Wextra -Wno-long-long -Wno-variadic-macros -pedantic -O3 -finline-functions -Wno-inline -Wall -pedantic -DBOOST_ALL_NO_LIB=1 -DBOOST_All_STATIC_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_SYSTEM_STATIC_LINK=1 -DNDEBUG -I"." -c -o "bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/chrono.o" "libs/chrono/src/chrono.cpp" clang-darwin.compile.c++ bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/thread_clock.o "xcrun" "clang" "-stdlib=libc++" "-std=c++11" -x c++ -O3 -Wextra -Wno-long-long -Wno-variadic-macros -pedantic -O3 -finline-functions -Wno-inline -Wall -pedantic -DBOOST_ALL_NO_LIB=1 -DBOOST_All_STATIC_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_SYSTEM_STATIC_LINK=1 -DNDEBUG -I"." -c -o "bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/thread_clock.o" "libs/chrono/src/thread_clock.cpp" clang-darwin.compile.c++ bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/process_cpu_clocks.o "xcrun" "clang" "-stdlib=libc++" "-std=c++11" -x c++ -O3 -Wextra -Wno-long-long -Wno-variadic-macros -pedantic -O3 -finline-functions -Wno-inline -Wall -pedantic -DBOOST_ALL_NO_LIB=1 -DBOOST_All_STATIC_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_SYSTEM_STATIC_LINK=1 -DNDEBUG -I"." -c -o "bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/process_cpu_clocks.o" "libs/chrono/src/process_cpu_clocks.cpp" RmTemps bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/libboost_chrono.a(clean) rm -f "bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/libboost_chrono.a" clang-darwin.archive bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/libboost_chrono.a "ar" rc "bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/libboost_chrono.a" "bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/chrono.o" "bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/thread_clock.o" "bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/process_cpu_clocks.o" "ranlib" -cs "bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/libboost_chrono.a" /usr/bin/ranlib: file: bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/libboost_chrono.a(thread_clock.o) has no symbols ranlib: file: bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/libboost_chrono.a(thread_clock.o) has no symbols common.copy stage/lib/libboost_chrono.a cp "bin.v2/libs/chrono/build/clang-darwin-osx/release/link-static/threading-multi/libboost_chrono.a" "stage/lib/libboost_chrono.a" clang-darwin.compile.c++ bin.v2/libs/context/build/clang-darwin-osx/release/link-static/threading-multi/unsupported.o "xcrun" "clang" "-stdlib=libc++" "-std=c++11" -x c++ -O3 -O3 -finline-functions -Wno-inline -Wall -DBOOST_ALL_NO_LIB=1 -DNDEBUG -I"." -c -o "bin.v2/libs/context/build/clang-darwin-osx/release/link-static/threading-multi/unsupported.o" "libs/context/src/unsupported.cpp" libs/context/src/unsupported.cpp:7:2: error: "platform not supported" #error "platform not supported" ^ 1 error generated. ...failed updating 1 target...

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boost::result_of and pure virtual functor leads to compile error
by oswin krause 30 Apr '13

30 Apr '13

Hi list, I am necountering an error when trying to use boost::result_of on a pure virtual base class. minimal example: struct Test{ typedef int result_type; virtual int operator()(int)=0; }; typedef boost::result_of<Test(int)>::type type; leads with gcc 4.8 (and with every compiler i know of) to the following output: Error: »type name« declared as function returning an abstract class type typedef boost::result_of<Test(int)>::type type; (actually in the original code where this showed up, gcc compiles it just fine only every other compiler fails, but in this very simple example, even gcc get's the message...) Any chance to use result_of in this setting? I clearly can't use the function call syntax here, which is a little bit annoying. Greetings, Oswin

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[Graph] Difference between astar_search and astar_search_tree
by Luis Torres 29 Apr '13

29 Apr '13

I didn't find the A* documentation very clear on this: when should one use astar_search, and when should one use astar_search_tree? Does the distinction have to do with whether the given heuristic is consistent? Thanks, Luis

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boost::serialization throwing “input stream error” on base class ptr XML serialization
by jvetter 26 Apr '13

26 Apr '13

Hello, This seems straight forward to me, but yet I'm stilling getting a input stream error and I don't understand why. The weird part about it is if I un-comment the serialization of the base class in my example it works, otherwise it does not. Here is the code: struct A { virtual ~A() {}; int i1 = 10; friend class boost::serialization::access; template <class Archive> void serialize(Archive& ar, const unsigned int version) { ar & make_nvp("int", i1); } }; struct B : A { virtual ~B() {}; float f1 = 5.0F friend class boost::serialization::access; template <class Archive> void serialize(Archive& ar, const unsigned int version) { ar & boost::serialization::base_object<A>(*this); ar & make_nvp("float", f1); } }; struct C : A { virtual ~C() {}; long l1 = 24; friend class boost::serialization::access; template <class Archive> void serialize(Archive& ar, const unsigned int version) { ar & boost::serialization::base_object<A>(*this); ar & make_nvp("long", l1); } }; //Why do these need to be wrappers?? namespace boost { namespace serialization { template<> struct is_wrapper<A*> : mpl::true_ {}; template<> struct is_wrapper<A> : mpl::true_ {}; template<> struct is_wrapper<const A> : mpl::true_ {}; } } BOOST_SERIALIZATION_ASSUME_ABSTRACT(A); BOOST_CLASS_EXPORT(B) BOOST_CLASS_EXPORT(C) int main(int argc, char** argv) { //A* a = new A(); A* b = new B(); A* c = new C(); //A* a1 = nullptr; A* a2 = nullptr; A* a3 = nullptr; ostringstream ostream; xml_oarchive oarchive(ostream); oarchive /*<< BOOST_SERIALIZATION_NVP(a)*/ << BOOST_SERIALIZATION_NVP(b) << BOOST_SERIALIZATION_NVP(c); istringstream istream(ostream.str()); xml_iarchive iarchive(istream); iarchive /*>> BOOST_SERIALIZATION_NVP(a1)*/ >> BOOST_SERIALIZATION_NVP(a2) >> BOOST_SERIALIZATION_NVP(a3); //delete a; delete b; delete c; //delete a1; delete a2; delete a3; } It's worth mentioning that this is with Boost 1.53 and GCC 4.8.0 w/ --std=c++11. The same code works fine in both cases worth the text and binary archives. I have tried changing the nvp's in the main to have the same key and in the input case no key, but I get the same error. Am I doing something wrong or is there an issue with the xml archive? Thanks, Jaime

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Re: [Boost-users] Boost, MinGW and SjLj
by Archie Campbell 26 Apr '13

26 Apr '13

2013/4/26 Archie Campbell: > Hi, > > I have compiled boost_1_53_0 using bjam on windows with MinGW (gcc-4.6.3). > > I am using CodeBlocks for IDE and have successfully linked against Qt5. > > Attempting to link against libboost_serialization produces undefined > references > to things like sjlj_unwind and archive_exception. > > What's going wrong? Do I need to flag the compiler to change exception > strategy? > > Thanks in advance. > > Archie This occurs when one of the libraries compiled using the not SJLJ build of MinGW. (dwarf, for example) I fixed it, eventually, after much messing around with PATH. The strawberry perl c compiler, an irrelevant sjlj build, had snuck in somewhere along the line and had been picked up by bjam. As it turns out, I had to download TDM-GCC-4.7.1, mingw & sjlj to build against Qt5. Boost, and my engine's code were happy to use Mingw 4.6.2, dwarf build, but once the libraries had compiled alright, complained badly during my code's compilation when I tried gcc 4.7.1. Spent the rest of the day fixing up windows IO and all those enchanting little differences between OS designs :P I now have at least four MinGW toolchains but I'm not looking for trouble. Archie

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