- Boost-users - lists.boost.org

Re: [Boost-users] [bind] Template deduction
by Robert Dailey 06 Mar '08

06 Mar '08

On Tue, Mar 4, 2008 at 7:16 PM, Marshall Clow <marshall(a)idio.com> wrote: > > Would this work? > std::for_each( myStrings.begin(), myStrings.end(), boost::bind( > &DoFoo<std::string>, 5, _1 ) ); Well, the example I gave was probably overly simple. The real example uses a boost::python::list, which can either take a char* or a std::string. At the time I'm doing the boost::bind, I do not know what type is being passed in.

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basename function in filesystem
by Alain Leblanc 06 Mar '08

06 Mar '08

Hi, Here's the description of the basename() function in the Filesystem library: template <class Path> typename Path::string_type basename(const Path & p); Returns: if p.leaf() contains a dot, returns the substring of p.leaf() starting at its beginning and ending at the last dot (the dot is not included). Otherwise, returns p.leaf() and if I run the following program ================================================== #include <string> #include <iostream> #include<boost/filesystem/operations.hpp> namespace bf = boost::filesystem; int main() { string name("/calvin/hobbes/xx.xml"); bf::path filepath(name); cerr << "Value for basename: " << basename(filepath.string().c_str()) << endl; } ================================================== I get as a result: Value for basename: xx.xml I seems like I should be getting 'xx'. Am I not understanding the description, or is there a problem with the library. a

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[boost.python] howto expose ptr_vector?
by Jörg Becker 06 Mar '08

06 Mar '08

Hello everyone. I have to expose a boost::ptr_vector. I'm wondering if I can use the indexing suite. But neither the docu nor google give me an answer. Are there any examples for the indexing_suite using a boost::ptr_vector or any other custom (non-stl) container? Thanks, Jörg

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[multi-index] question for a complex query
by Ovanes Markarian 06 Mar '08

06 Mar '08

Hello *, I currently need to implement the following use case and was wondering if this is possible with multi-index: I have a class, for simplicity all members are public wihtout accessors and mutators: class entry { public: field x; field y; filed z; }; I need a multi-index index to remember the order in which the elements were inserted and non uniquely index the inserted elements by hash of field x; Now a client could do the following queries: - get all entries in the order they were inserted (this is easy and I know how to do it) - get all entries which satisfy field x parameter in the order they were inserted. I know that I can retrieve the values dependent on hash(x), but these are probably not sorted. I know that I can project iterators, but can I project (range_retireved_via_hashed_X) to (range_retrieved_for_sequence_of_X) May be I miss smth here or should split my data in some other way to satisfy this condition. With Kind Regards, Ovanes Markarian

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Please help: Getting started with Boost
by Nishant Mittal 06 Mar '08

06 Mar '08

I have a 64 bit red hat linux (also 64 bit) box. 1) I downloaded boost from boost_1_34_1.tar.bz2 <http://downloads.sourceforge.net/boost/boost_1_34_1.tar.bz2?modtime=1185241 108&big_mirror=0> 2) Unizipped and installed it (./configure , make install ) everything worked fine. Questions: 1) How do I check if I now have the 64 bit version of boost? 2) I see that all libraries were put into /usr/local/lib and I can compile my hello world code with the following command. * $ g++ hello.cpp -lboost_thread-gcc41-mt-1_34_1 but when I try to run the created a.out file I get a file not found error msg. * $ ./a.out * ./a.out: error while loading shared libraries: libboost_thread-gcc41-mt-1_34_1.so.1.34.1: cannot open shared object file: No such file or directory I did an ldd and this is the output. $ ldd a.out libboost_thread-gcc41-mt-1_34_1.so.1.34.1 => not found libstdc++.so.6 => /usr/lib64/libstdc++.so.6 (0x0000003a6aa00000) libm.so.6 => /lib64/libm.so.6 (0x0000003a5a400000) libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x0000003a68600000) libc.so.6 => /lib64/libc.so.6 (0x0000003a5a000000) /lib64/ld-linux-x86-64.so.2 (0x0000003a59c00000) I am stuck and cannot make progress. I appreciate any help on this. Thanks Nishant

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[BGL] vertex_descriptors in STL containers
by Torsten Sadowski 06 Mar '08

06 Mar '08

Hi, I have written a program that works if I use vecS for the vertices and fails often with a crash when I use listS. vecS vertex descriptors are effectivly int so they pose no problem when used in std::set and std::map but listS vertex descriptors are of type void*. Could it be that comparison fails in the sets or could I have problems with a copy constructor somewhere? I know that STL is not designed to handle pointers but in my case the pointers could just be handled for their address value. The graph is not changed during my calculations. Cheers, Torsten

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negating a functor in a remove_copy_if
by PJ Durai 06 Mar '08

06 Mar '08

Hello everyone, I couldn't figure out how to use a logical negation in the following situation. struct IsConditionValid : public unary_function<Event, bool> { public: bool operator() (const Event& event)const {} }; remove_copy_if(events.begin(), events.end(), back_inserter(result), IsConditionValid()); <-- how to negate the condition object? What I really need is '! IsConditionValid()'. How can it be done using may be boost::bind ? appreciate your time. thanks pj

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Boost.Math.StatisticalDistributions
by johneddy101＠comcast.net 06 Mar '08

06 Mar '08

Hello, I realize that this library is not yet part of the boost distribution but I am using it and have come accross an issue. I am concerned that the logic in the various check functions may be flawed. Take for example the check_uniform function. The logic is as follows: if lower Ok && upper Ok && lower < upper return true else raise error stating that lower must be less than upper return false end if The functions used to determine if lower and upper are ok will raise errors if appropriate. If the policy is such that raising an error does not cause a throw, then control will return to the check_uniform method with an indication that lower or upper is not ok and we will enter the else block. Herein lies the problem. Consider the following scenario: creating a uniform distribution with: lower = 0.0 upper = postitive infinity Check upper will fail and send a message about the infinity. Enter the else block. A message will be raised that states that the lower parameter is not less than the upper. This is my concern. I believe the second message is unnecessary and potentially incorrect/misleading. Perhaps logic like shown below would be more appropriate: if lower not Ok || upper not Ok then return false else if lower >= upper raise error stating that lower must be less than upper return false else return true end if Thanks, John

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[regex] Question about pattern
by office＠mgs.co.at 06 Mar '08

06 Mar '08

Hi; I'm a newbie to regex patterns and need help in a relative simple task: I use boost::regex with perl syntax and I have to parse user input that provides a feature similar to the conditional formatting of cells in OpenOffice Calc. The string the user enters looks like this: >=30 [fg:red] [bg:white] or <0.0 [fg:none] [bg:transparent] First the user can enter an optional operator (> < <> = <= >=) followed by a integer or floating point number. This whole term is optional so [fg:red] [bg:white] is also a valid expression. The terms for color selection are partly optional, so valid expressions are [fg:red] or [bg:white] or [fg:red][bg:white] or [bg:white][fg:red] The key words for foreground and background colors are predefined by the software (red, green, blue, transparent, none, ...). I tried starting with a pattern like (C++ syntax for strings) ^(?:(<|<=|>|>=|=|<>){1}((?:-|\\+)?[0-9]+(?:\\.[0-9]+|\\,[0-9]+)?))?(?:\\s*)(?:(\\[FG:(?:BLUE|RED|GREEN|BLACK|YELLOW|WHITE|CYAN|NONE)\\])|(\\[BG:(?:BLUE|RED|GREEN|BLACK|YELLOW|WHITE|CYAN)\\])|(\\[FG:(?:BBLUE|RED|GREEN|BLACK|YELLOW|WHITE|CYAN|NONE)\\])(?:\\s*)(\\[BG:(?:BLUE|RED|GREEN|BLACK|YELLOW|WHITE|CYAN)\\])){1}$ But this does not allow the [fg:][bg:] terms to be interchanged and also when a new color or style will be added to the format class I have to change the pattern three times. I tried backward references with no success. So any help is very welcome Thanks in advance Martin

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including boost/thread.hpp gives compile error under VS7 in utility\base_from_member.hpp
by jason72＠internode.on.net 06 Mar '08

06 Mar '08

Using Visual Studio 2003 (VS7) and boost 1.34.1, I have simply declared the following code and I get the resulting errors: Code: #pragma once #include <deque> #include <boost/thread.hpp> using namespace std; <SNIP> Compiler output: cl /c /W3 /G6 /GF /Gy /nologo /DNDEBUG /DWIN32 /D_WIN32 /D_WIN32_WINNT=0x0500 /DWINVER=0x0500 /D_WIN32_IE=0x060 0 /D_AFXDLL /D_WTL_NO_CSTRING /D_WTL_NO_WTYPES /D_WTL_NO_UNION_CLASSES -D_X86_=1 /Ox /Z7 /I\src\r870\develop\work\pcd m\std\include /DNT /Dpcdm /DDBREL=870 /D_WIN32_DCOM -GX /DREGISTER_PROXY_DLL /GR /EHsc /MD /Fohtsserver.obj htsserver.cpp.cpp htsserver.cpp.cpp c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2143: syntax error : missing ',' before 'constant' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(78) : see reference to class template instantiation 'boost::base_from_member<MemberType,UniqueID>' being compiled c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2226: syntax error : unexpected type 'T0' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2334: unexpected token(s) preceding ':'; skipping apparent function body c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2143: syntax error : missing ',' before 'constant' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2226: syntax error : unexpected type 'T0' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2334: unexpected token(s) preceding ':'; skipping apparent function body c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2143: syntax error : missing ',' before 'constant' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2226: syntax error : unexpected type 'T0' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2334: unexpected token(s) preceding ':'; skipping apparent function body c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2143: syntax error : missing ',' before 'constant' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2226: syntax error : unexpected type 'T0' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2334: unexpected token(s) preceding ':'; skipping apparent function body c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2143: syntax error : missing ',' before 'constant' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(76) : error C2226: syntax error : unexpected type 'T0' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(78) : error C2143: syntax error : missing ';' before '}' c:\apps\boost_1_34_1\boost\utility\base_from_member.hpp(78) : error C2238: unexpected token(s) preceding ';' c:\apps\VS .NET 2003\Vc7\include\ostream(604) : fatal error C1903: unable to recover from previous error(s); stopping compilation NMAKE : fatal error U1077: 'cl' : return code '0x2' Stop. Note that I havent declared or used any of the threading or mutex objects yet. It is not possible to upgrade compiler version for this project. Regards, Jason

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