Re: Request to know about "dynamic expression evaluation"

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@rrsd.com>
Subject: Re: [Boost-users] Request to know about "dynamic expression
evaluation"
To: boost-users@lists.boost.org
Message-ID: <ffl6mi$25v$1@ger.gmane.org>
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@credit-suisse.com> wrote in message news:F444CAE5E62A714C9F45AA292785BED327C3BE87@esng11p33001.sg.csfb.com...

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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Message: 2
Date: Tue, 23 Oct 2007 12:00:10 -0500
From: "Graham Reitz" <graham.cpp@gmail.com>
Subject: [Boost-users] seeding a boost::random number generator...?
To: boost-users <Boost-users@lists.boost.org>
Message-ID:
<d079efe40710231000p388c51fs593ad3fe34ffefc0@mail.gmail.com>
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@MarchNetworks.com>
Subject: [Boost-users] Thread Library Problem
To: <boost-users@lists.boost.org>
Message-ID:
<F77675CA7EBC9C47A2515D2E8B2A6F2FA275D7@SVRSEXCH1.scottsdale.marchnetworks.com>

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/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/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

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Message: 4
Date: Tue, 23 Oct 2007 12:09:55 -0500
From: "Oleg Udovenko" <oleg@enginia.com>
Subject: [Boost-users] boost::serialization Is there any way to get
        rid of compiler warnings(C4103, ...) on VC++ 2005?
To: <boost-users@lists.boost.org>
Message-ID:
        <219C1F14CB67594B81ECCAA1587AEAD501E09E21@static-207-54-102-51.ptr.terago.ca>

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
og.htm"

1>ExampleXmlSave - 0 error(s), 68 warning(s)

========== Rebuild All: 1 succeeded, 0 failed, 0 skipped ==========

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