Re: [Boost-users] Request to know about "dynamic expression evaluation"

From: Borse, Ganesh (ganesh.borse_at_[hidden])
Date: 2007-10-24 22:35:22

Hi,
You recommended checking the "expression templates".
However, expression templates (xpressive) provides the means of parsing the input expressions in to tokens.
It does not have the support for evaluating these expressions. --- please correct me if I'm wrong.
Thanks,
Ganesh
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> Today's Topics:
> 
>    1. Re: Request to know about "dynamic expression	evaluation"
>       (Robert Ramey)
>    2. seeding a boost::random number generator...? (Graham Reitz)
>    3. Thread Library Problem (Andres Herrera)
>    4. boost::serialization Is there any way to get rid of	compiler
>       warnings(C4103, ...) on VC++ 2005? (Oleg Udovenko)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Tue, 23 Oct 2007 09:15:17 -0700
> From: "Robert Ramey" <ramey_at_[hidden]>
> Subject: Re: [Boost-users] Request to know about "dynamic expression
> 	evaluation"
> To: boost-users_at_[hidden]
> Message-ID: <ffl6mi$25v$1_at_[hidden]>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> Request to know about "dynamic expression evaluation"Look for "expression templates"
> 
> Robert Ramey
>   "Borse, Ganesh" <ganesh.borse_at_[hidden]> wrote in message news:F444CAE5E62A714C9F45AA292785BED327C3BE87_at_[hidden] <news:F444CAE5E62A714C9F45AA292785BED327C3BE87_at_[hidden]> ...
>   Hi,
>   I would like to perform the dynamic expression evaluation in my c++ application. 
>   The dynamic expressions are like the SQL queries. 
>   Since the expressions could be nested & hence the parsing & evaluation of such expressions is reducing the performance of my application.
> 
>   May I please know, whether BOOST provides a support for such dynamic expression evaluation in C++? 
>   Please guide. 
> 
>   Thanks in advance for the guidance. 
> 
>   Regards,
>   Ganesh 
> 
> 
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> ------------------------------
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> Message: 2
> Date: Tue, 23 Oct 2007 12:00:10 -0500
> From: "Graham Reitz" <graham.cpp_at_[hidden]>
> Subject: [Boost-users] seeding a boost::random number generator...?
> To: boost-users <Boost-users_at_[hidden]>
> Message-ID:
> 	<d079efe40710231000p388c51fs593ad3fe34ffefc0_at_[hidden]>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> I am little confused on how to see a random generator.
> 
> What am I missing?
> 
>     // Grab the seed
>     HighResTimer::Time time_secs = high_res_timer.getTime();
> 
>     // Go ahead and truncate, it's just a seed
>     boost::int32_t time = static_cast<boost::int32_t>(time_secs * 100000);
> 
>     // produces randomness out of thin air
>     // see pseudo-random number generators
>     boost::mt19937 rng;
>     rng.seed();  // How do you seed this with the time?
> 
>     // distribution that maps to 0..1
>     // see random number distributions
>     boost::uniform_real<> zero_to_one(0,1);
> 
>     // glues randomness with mapping
>     boost::variate_generator<boost::mt19937&, boost::uniform_real<> >
>         be_random zero_to_one);
> 
> 
> ------------------------------
> 
> Message: 3
> Date: Tue, 23 Oct 2007 09:55:05 -0700
> From: "Andres Herrera" <aherrera_at_[hidden]>
> Subject: [Boost-users] Thread Library Problem
> To: <boost-users_at_[hidden]>
> Message-ID:
> 	<F77675CA7EBC9C47A2515D2E8B2A6F2FA275D7_at_[hidden]>
> 	
> Content-Type: text/plain; charset="us-ascii"
> 
> Hi,
> 
>  
> 
> I'm new to Boost, I've been trying to use the Thread library that boost
> offers. I'm on a Kubuntu 7.1 box using G++ 4.1 Compiler with Boost 1.34.
> I've only been successful compiling my project when including
> libboost_thread-gcc41-mt-d.so library file. I would much rather use the
> .a file however, If I try to use the libboost_thread-gcc41-mt-d.a
> library file, i get the following errors:
> 
>  
> 
> /home/andresh/DVRTranslators/Boost/lib/libboost_thread-gcc41-mt-d.a(thre
> ad.o): In function `boost::thread::join()':
> 
> /home/andresh/DVRTranslators/Boost/boost_1_34_1/libs/thread/src/thread.c
> pp:226: undefined reference to `pthread_join'
> 
> /home/andresh/DVRTranslators/Boost/lib/libboost_thread-gcc41-mt-d.a(thre
> ad.o): In function `~thread':
> 
> /home/andresh/DVRTranslators/Boost/boost_1_34_1/libs/thread/src/thread.c
> pp:191: undefined reference to `pthread_detach'
> 
> /home/andresh/DVRTranslators/Boost/boost_1_34_1/libs/thread/src/thread.c
> pp:191: undefined reference to `pthread_detach'
> 
> /home/andresh/DVRTranslators/Boost/lib/libboost_thread-gcc41-mt-d.a(thre
> ad.o): In function `thread':
> 
> /home/andresh/DVRTranslators/Boost/boost_1_34_1/libs/thread/src/thread.c
> pp:156: undefined reference to `pthread_create'
> 
> /home/andresh/DVRTranslators/Boost/boost_1_34_1/libs/thread/src/thread.c
> pp:156: undefined reference to `pthread_create'
> 
> /home/andresh/DVRTranslators/Boost/lib/libboost_thread-gcc41-mt-d.a(mute
> x.o): In function `boost::try_mutex::do_trylock()':
> 
> /home/andresh/DVRTranslators/Boost/boost_1_34_1/libs/thread/src/mutex.cp
> p:260: undefined reference to `pthread_mutex_trylock'
> 
> collect2: ld returned 1 exit status
> 
> make: *** [listener] Error 1
> 
>  
> 
> I've used the Regex and Filesystem .a library files without a problem,
> but the Thread .a library file won't work. 
> 
>  
> 
> Here is my code:
> 
>  
> 
> #include <boost/thread/thread.hpp>
> 
> #include <iostream>
> 
>  
> 
> void helloworld()
> 
> {
> 
>     std::cout << "Hello World!" << std::endl;
> 
> }
> 
>  
> 
> int main()
> 
> {
> 
>        std::cout << "STARTING ";
> 
>     boost::thread thrd(&helloworld);
> 
>     thrd.join();
> 
>        helloworld(); 
> 
>        return 0;
> 
> }
> 
>  
> 
>  
> 
> Here is my MakeFile:
> 
>  
> 
>  
> 
> all: listener
> 
>  
> 
> listener: TestBoost.cpp 
> 
>        g++ TestBoost.cpp -o listener -I
> /home/andresh/DVRTranslators/Boost/include/boost-1_34_1/
> /home/andresh/DVRTranslators/Boost/lib/libboost_thread-gcc41-mt-d.a
> 
>  
> 
>  
> 
>  
> 
> Any help is greatly appreciated. If you need any more information please
> ask, I want to try and get this problem resolved soon.
> 
>  
> 
> Thanks,
> 
>  
> 
> Andres
> 
>  
> 
>  
> 
> -------------- next part --------------
> HTML attachment scrubbed and removed
> 
> ------------------------------
> 
> Message: 4
> Date: Tue, 23 Oct 2007 12:09:55 -0500
> From: "Oleg Udovenko" <oleg_at_[hidden]>
> Subject: [Boost-users] boost::serialization Is there any way to get
> 	rid of	compiler warnings(C4103, ...) on VC++ 2005?
> To: <boost-users_at_[hidden]>
> Message-ID:
> 	<219C1F14CB67594B81ECCAA1587AEAD501E09E21_at_[hidden]>
> 	
> Content-Type: text/plain; charset="us-ascii"
> 
> Hi,
> 
>  
> 
> I'm compiling the examples from the boost::serialization library with
> VC++ 2005, and getting a lot of warnings, they are quite annoying.
> 
> How can I get rid of them?
> 
>  
> 
> Appreciate any suggestions.
> 
>  
> 
> Thanks,
> 
> Oleg.
> 
>  
> 
>  
> 
> 1>------ Rebuild All started: Project: ExampleXmlSave, Configuration:
> Release x64 ------
> 
> 1>Deleting intermediate and output files for project 'ExampleXmlSave',
> configuration 'Release|x64'
> 
> 1>Compiling...
> 
> 1>stdafx.cpp
> 
> 1>Compiling...
> 
> 1>ExampleXmlSave.cpp
> 
> 1>C:\WORK\STL\boost\boost_1_34_1\boost/config/abi_prefix.hpp(19) :
> warning C4103:
> 'c:\work\stl\boost\boost_1_34_1\boost\config\abi_prefix.hpp' : alignment
> changed after including header, may be due to missing #pragma pack(pop)
> 
> 1>C:\WORK\STL\boost\boost_1_34_1\boost/archive/detail/abi_prefix.hpp(11)
> : warning C4103:
> 'c:\work\stl\boost\boost_1_34_1\boost\archive\detail\abi_prefix.hpp' :
> alignment changed after including header, may be due to missing #pragma
> pack(pop)
> 
> 1>C:\WORK\STL\boost\boost_1_34_1\boost/archive/basic_text_oprimitive.hpp
> (54) : warning C4103:
> 'c:\work\stl\boost\boost_1_34_1\boost\archive\basic_text_oprimitive.hpp'
> : alignment changed after including header, may be due to missing
> #pragma pack(pop)
> 
>  
> 
> ...
> 
>  
> 
> 1>C:\WORK\STL\boost\boost_1_34_1\boost/serialization/collections_save_im
> p.hpp(38) : warning C4267: 'initializing' : conversion from 'size_t' to
> 'unsigned int', possible loss of data
> 
> 1>
> C:\WORK\STL\boost\boost_1_34_1\boost/serialization/list.hpp(39) : see
> reference to function template instantiation 'void
> boost::serialization::stl::save_collection<Archive,std::list<_Ty>>(Archi
> ve &,const Container &)' being compiled
> 
> 1>        with
> 
> 1>        [
> 
> 1>            Archive=boost::archive::xml_oarchive,
> 
> 1>            _Ty=std::pair<bus_schedule::trip_info,bus_route *>,
> 
> 1>
> Container=std::list<std::pair<bus_schedule::trip_info,bus_route *>>
> 
> 1>        ]
> 
> 1>
> C:\WORK\STL\boost\boost_1_34_1\boost/serialization/split_free.hpp(45) :
> see reference to function template instantiation 'void
> boost::serialization::save<Archive,std::pair<_Ty1,_Ty2>,std::allocator<_
> Ty>>(Archive &,const std::list<_Ty> &,const unsigned int)' being
> compiled
> 
> 1>        with
> 
> 1>        [
> 
> 1>            Archive=boost::archive::xml_oarchive,
> 
> 1>            _Ty1=bus_schedule::trip_info,
> 
> 1>            _Ty2=bus_route *,
> 
> 1>            _Ty=std::pair<bus_schedule::trip_info,bus_route *>
> 
> 1>        ]
> 
>  
> 
> ...
> 
> 1>Linking...
> 
> 1>   Creating library
> C:\WORK\STL\TST\ExampleXmlSave\x64\Release\ExampleXmlSave.lib and object
> C:\WORK\STL\TST\ExampleXmlSave\x64\Release\ExampleXmlSave.exp
> 
> 1>Generating code
> 
> 1>Finished generating code
> 
> 1>Embedding manifest...
> 
> 1>Build log was saved at
> "file://c:\WORK\STL\TST\ExampleXmlSave\ExampleXmlSave\x64\Release\BuildL <file://c:\WORK\STL\TST\ExampleXmlSave\ExampleXmlSave\x64\Release\BuildL> 
> og.htm"
> 
> 1>ExampleXmlSave - 0 error(s), 68 warning(s)
> 
> ========== Rebuild All: 1 succeeded, 0 failed, 0 skipped ==========
> 
>  
> 
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