April 2008 - Boost-users - lists.preview.boost.org

[date_time] posix_time::time_duration::operator<< fails for hours>23
by Soren Dreijer 04 Feb '09

04 Feb '09

I'm creating a posix_time::time_duration object based on the minutes() helper function. If I specify a large value, such as 2000, I get a time_duration of 33:20:00. Take a look at the following piece of code, though: time_duration td = minutes(2000); cout << to_simple_string(td); // OK cout << td; // Fails with an assertion in VS2008 The latter call fails with the following assertion in strftime.c on line 658: _VALIDATE_RETURN( ( ( timeptr->tm_hour >=0 ) && ( timeptr->tm_hour <= 23 ) ), EINVAL, FALSE) Apparently, operator<< expands to _expandtime(), which doesn't allow values for the hour to be greater than 23. Is this intended behavior, or should I just always use to_simple_string() rather than the convenient operator<< ?

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[graph] property_map from bundled properties in a subgraph, how?
by Christian Rössel 28 Nov '08

28 Nov '08

Hi, thanks for the great graph library! My first attempts with boost.graph were quite successful, but now I'm stuck. My question is: How can I get a property_map from bundled properties in a subgraph? (boost 1.34.1, g++ and VC8) In the beginning I had a bidirectional graph with bundled properties and I used a property map from the edge's bundled properties: #include <boost/graph/adjacency_list.hpp> #include <boost/graph/subgraph.hpp> using namespace boost; struct VertexProperty { // ... }; struct EdgeProperty { double length_; // ... }; typedef adjacency_list<vecS, vecS, bidirectionalS, VertexProperty, EdgeProperty> Graph; int main () { Graph g; typedef property_map<Graph, double EdgeProperty::*>::type EdgeWeightMap; EdgeWeightMap ewm = get (&EdgeProperty::length_, g); // use ewm in an algorithm ... return 0; } Everthing worked fine. Then, I had to change the graph-type from adjacency_list to subgraph ... typedef subgraph< adjacency_list<vecS, vecS, bidirectionalS, property<vertex_index_t, int, VertexProperty>, property<edge_index_t, int, EdgeProperty> > > Subgraph; int main () { Subgraph g; typedef property_map<Subgraph, double EdgeProperty::*>::type EdgeWeightMap; EdgeWeightMap ewm = get (&EdgeProperty::length_, g); // use ewm in an algorithm ... return 0; } ... and got this compile error: In instantiation of `boost::property_map<Subgraph, double EdgeProperty::*>': subgraph_property_map.cpp:45: instantiated from here ../../vendor/boost_1_34_1-multithread/boost/graph/properties.hpp:355: error: no type named `vertex_bundled' in `class Subgraph' ../../vendor/boost_1_34_1-multithread/boost/graph/properties.hpp:356: error: no type named `edge_bundled' in `class Subgraph' ../../vendor/boost_1_34_1-multithread/boost/graph/properties.hpp:360: error: no type named `vertex_bundled' in `class Subgraph' ../../vendor/boost_1_34_1-multithread/boost/graph/properties.hpp:360: error: `value' is not a member of `<declaration error>' ../../vendor/boost_1_34_1-multithread/boost/graph/properties.hpp:364: error: no type named `vertex_bundled' in `class Subgraph' ../../vendor/boost_1_34_1-multithread/boost/graph/properties.hpp:364: error: `value' is not a member of `<declaration error>' ../../vendor/boost_1_34_1-multithread/boost/graph/properties.hpp:367: error: no type named `vertex_bundled' in `class Subgraph' ../../vendor/boost_1_34_1-multithread/boost/graph/properties.hpp:367: error: `value' is not a member of `<declaration error>' ../../vendor/boost_1_34_1-multithread/boost/graph/properties.hpp:369: error: no type named `vertex_bundled' in `class Subgraph' ../../vendor/boost_1_34_1-multithread/boost/graph/properties.hpp:369: error: `value' is not a member of `<declaration error>' Is there a way to use property maps from bundled properties in a subgraph? If not, can you give me a hint for a workaround, please. Thanks and best regards, Christian __

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Random: Using random generators with runtime parameters
by Hans Mull 23 Nov '08

23 Nov '08

Hi! How can I use random generators with multiple parameters such as linear_congruential with parameters that are only known at runtime? Thanks in advance, Hans

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boost::program_options
by Duy Nguyen 09 Oct '08

09 Oct '08

When I try to use the boost::program_options library to read a property file, I got the error when I run "make" on Cygwin (I installed Cygwin on WIndows XP). > make g++.exe -I /cygdrive/c/MyTest/Test1/include/boost-1_34_1/ -c TestInit.cpp Test.cpp TestDriver.cpp g++.exe -I /cygdrive/c/MyTest/Test1/include/boost-1_34_1/ -c TestInit.cpp Test.cpp TestDriver.cpp g++.exe -I /cygdrive/c/MyTest/Test1/include/boost-1_34_1/ -c TestInit.cpp Test.cpp TestDriver.cpp g++.exe TestInit.o Test.o TestDriver.o -o "TestDriver" -L/cygdrive/c/MyTest/Test1/lib -lboost_program_options-gcc34-mt-d-1_34_1 -lg2c Info: resolving vtable for boost::program_options::variables_mapby linking to __imp___ZTVN5boost15program_options13variables_mapE (auto-import) Then when I run my program, it does not work. If I comment out the "try ... catch" block which uses the boost::propram_options library then it compiles and works fine. Please show me how to fix it. Thank you.

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boost::filesystem exception not caught on MacOS X
by Lothar May 21 Sep '08

21 Sep '08

Hi, I have a strange problem that an exception thrown by a boost::filesystem directory_iterator is not caugth on MacOS X. Please consider the following code: ("const string &dir" is a parameter) bool retVal = true; try { directory_iterator i(dir); directory_iterator end; while (i != end) { // do something ++i; } } catch (...) { retVal = false; } While this works perfectly on Windows and Linux (the exception is caught fine), on MacOS I get the following: terminate called after throwing an instance of 'boost::filesystem::basic_filesystem_error<boost::filesystem::basic_path<std::string, boost::filesystem::path_traits> >' what(): boost::filesystem::basic_directory_iterator constructor Abort trap The program runs fine (withouth the trap) if I comment out the upper lines. I use the boost 1.34.0 lib built as universal binary on MacOS 10.5, according to the instructions at http://svn.boost.org/trac/boost/wiki/CMakeConfigAndBuild I link to the static non-debug mt version of boost_filesystem. Exceptions within my program are caught fine, just this boost exception is not caught. The program is also compiled as non-debug. Any help would be very much appreciated. Regards, Lothar

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Boost Graph Library and Boehm Garbage Collector
by FBSL 08 Sep '08

08 Sep '08

Hello I am having trouble to garbage-collect adjacency_list<>. I have instanciated it with correctly garbage-collected vectors and lists (I have copied vecS and listS definitions, and added Boehm GC's default allocator so that they are garbage-collected). In my application I need to dynamically allocate many graphs, but it does not work, there is a (big) memory leak. Unfortunately, there is no template argument in adjacency_list<> to specify Boehm GC's allocator. Does anyone have a hint ? Snippet code "main.cpp" follows, compiled with Boost Graph Library 1.32, Boehm GC 6.4 and G++ 3.3.5, with command line : $ g++ -o main main.cpp -lgc -lgccpp -- #include <boost/graph/adjacency_list.hpp> #include <gc/gc_allocator.h> #include <gc/gc_cpp.h> #include <iostream> #include <vector> #include <list> using namespace std; using namespace boost; namespace boost { struct collected_vecS {}; struct collected_listS {}; template <class ValueType> struct container_gen<collected_vecS, ValueType> { typedef vector<ValueType,gc_allocator<ValueType> > type; }; template <class ValueType> struct container_gen<collected_listS, ValueType> { typedef list<ValueType,gc_allocator<ValueType> > type; }; template <> struct parallel_edge_traits<collected_vecS> { typedef allow_parallel_edge_tag type; }; template <> struct parallel_edge_traits<collected_listS> { typedef allow_parallel_edge_tag type; }; namespace detail { template <> struct is_random_access<collected_vecS> { enum { value = true }; typedef true_type type; }; } } typedef adjacency_list<collected_vecS, collected_vecS, directedS, no_property, no_property, no_property, collected_listS> graph; int main() { // leaks... while(true){ graph * g=new (UseGC) graph; for(unsigned int i=0; i<100; ++i){ add_vertex(*g); } for(unsigned int i=0; i<100; ++i){ for(unsigned int j=0; j<100; ++j){ add_edge(i,j,*g); } } } }

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boost on apple gcc 4.2
by Daniel Oberhoff 07 Aug '08

07 Aug '08

Hi, Has anyone successfully used boost with the "new" apple gcc 4.2? I would like to since gcc42 has openmp, but I cant seem to be able to use boost. I compiled and installed boost with apple gcc 4.2 by directly using bjam with --toolset=darwin-4.2. When I try to use it I get an error (detailed output of gcc below) which hints towards problems with inline assembly. Actually, to get it compiled at all I had to set -fasm-blocks. Am I missing a flag of sorts? Or is it "just" another woe with apple's modified assembler? Daniel error message of gcc4.2 with boost::filesystem: In file included from /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base.hpp:32, from /opt/boost-gcc4.2/include/boost-1_35/boost/detail/shared_count.hpp:29, from /opt/boost-gcc4.2/include/boost-1_35/boost/shared_ptr.hpp:28, from /opt/boost-gcc4.2/include/boost-1_35/boost/filesystem/path.hpp:19, from /opt/boost-gcc4.2/include/boost-1_35/boost/filesystem/operations.hpp:17, from /opt/boost-gcc4.2/include/boost-1_35/boost/filesystem.hpp:16, from mmm_fileloader.hpp:12, from mmm_tool_gui.hpp:5, from mmm_tool_gui.cpp:1: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘int boost::detail::atomic_exchange_and_add(int*, int)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:46: error: expected `)' before ‘:’ token /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘void boost::detail::atomic_increment(int*)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:62: error: expected `)' before ‘:’ token /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘int boost::detail::atomic_conditional_increment(int*)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:88: error: expected `)' before ‘:’ token In file included from /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base.hpp:32, from /opt/boost-gcc4.2/include/boost-1_35/boost/detail/shared_count.hpp:29, from /opt/boost-gcc4.2/include/boost-1_35/boost/shared_ptr.hpp:28, from /opt/boost-gcc4.2/include/boost-1_35/boost/filesystem/path.hpp:19, from /opt/boost-gcc4.2/include/boost-1_35/boost/filesystem/operations.hpp:17, from /opt/boost-gcc4.2/include/boost-1_35/boost/filesystem.hpp:16, from mmm_fileloader.hpp:12, from mmm_tool_gui.hpp:5, from mmm_tool_2.cpp:3: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘int boost::detail::atomic_exchange_and_add(int*, int)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:46: error: expected `)' before ‘:’ token /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘void boost::detail::atomic_increment(int*)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:62: error: expected `)' before ‘:’ token /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘int boost::detail::atomic_conditional_increment(int*)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:88: error: expected `)' before ‘:’ token In file included from /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base.hpp:32, from /opt/boost-gcc4.2/include/boost-1_35/boost/detail/shared_count.hpp:29, from /opt/boost-gcc4.2/include/boost-1_35/boost/shared_ptr.hpp:28, from /opt/boost-gcc4.2/include/boost-1_35/boost/archive/shared_ptr_helper.hpp:23, from /opt/boost-gcc4.2/include/boost-1_35/boost/archive/polymorphic_iarchive.hpp:161, from mmm_tool_net.hpp:8, from mmm_tool_net.cpp:1: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘int boost::detail::atomic_exchange_and_add(int*, int)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:46: error: expected `)' before ‘:’ token /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘void boost::detail::atomic_increment(int*)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:62: error: expected `)' before ‘:’ token /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp: In function ‘int boost::detail::atomic_conditional_increment(int*)’: /opt/boost-gcc4.2/include/boost-1_35/boost/detail/sp_counted_base_gcc_x86.hpp:88: error: expected `)' before ‘:’ token

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[DateTime] 1.35.0: Patch to fix warning
by Peter Klotz 03 Aug '08

03 Aug '08

The attached patch fixes an unused parameter warning in boost/date_time/time.hpp. Best regards, Peter.

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[Conversion] imprecision with lexical_cast from double to std::string
by Andreas Ries 30 Jul '08

30 Jul '08

Hi, I'm using the borland toolset 5.8.2 under Win XP and have a problem doing the following: double val = 795.6352; string result = boost::lexical_cast <string> (val); the resulting string is: "795.63520000000005" with boost 1_35_0 the resulting string is: "795.6352000000001" with boost_1_34_0 Can anybody help?

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[statechart] history transitions make state-local-storage "un-cool"
by Mick Hollins 26 Jun '08

26 Jun '08

Apologies if this has been discussed before, but I couldn't find any mention of it: I am currently using the history facility of boost::fsm. I've discovered that when I re-enter a state, X, via a history transition I don't actually re-enter the same instance of X that I was in before, but instead enter a newly constructed instance of X. I just checked the UML spec regarding history transitions and it says that "Any necessary entry actions are performed", so given that boost::fsm uses constructors to represent entry actions I guess a new instance of X has to be constructed to ensure UML compliance. My actual concern is the effect this has on the "coolness" of state-local-storage (see http://boost-sandbox.sourceforge.net/libs/statechart/doc/faq.html#Whats_so_…) It seems to me that state-local-storage, which I agree is generally cool, is particularly un-cool (and bug-inducing) in the presence of history transitions. I'm not sure what a good alternative is, but just thought I'd raise the discussion. cheers, mick PS: does the history facility display the same semantics in boost::statechart? I plan to move to statechart real soon now ...

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