June 2010 - Boost-users - lists.boost.org

[Filesystem] feedback on operator<<
by John Dlugosz 15 Jun '10

15 Jun '10

The "inserter" for paths needs a manipulator that specifies whether portable or system form is output. It may need OS-dependant flags too, to specify details about how escaping is done, quotes added, etc. --John TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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[bind] static member function binding
by Stefan Strasser 15 Jun '10

15 Jun '10

Hi, does Boost.Bind contain anything to create a function object that is statically bound to a member function? IIUC all function objects created by bind contain a function pointer, so they have overhead compared to a manual function object. something like: struct A{ void f(); } A *a; bind<void (A::*)(),&A::f>(a); -> function object bound to "a", calling A::f

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boost serialization saving a linked list
by tronix 15 Jun '10

15 Jun '10

Hi all, I'm learning using the boost serialization libraries. Can someone point me to references which use boost serialization libraries to save a linked list to a file and again read it/ parse the list. I'm not able to find simple examples that'll help me in understanding the basic points. Thanks, ----- "tron"ix -- View this message in context: http://old.nabble.com/boost-serialization-saving-a-linked-list-tp28885853p2… Sent from the Boost - Users mailing list archive at Nabble.com.

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Re: [Boost-users] spirit and property_tree headers conflict
by Artem Kozlov 15 Jun '10

15 Jun '10

>>>> Hello, >>>> >>>> When attempting to compile a program which includes the following >>> headers >>>> (at once): >>>> >>>> #include<boost/property_tree/json_parser.hpp> >>>> #include<boost/spirit/include/qi.hpp> >>> >>> I suspect this is because the JSON parser is implemented in >>> Spirit.Classic. I eventually want to switch to Qi, but until then, I have >>> no idea what to do. I thought Classic and Qi can coexist, but maybe I'm >>> doing something wrong. >> >>> It should co-exist. What are the problems, exactly? >> >> Well, here is the bunch of errors that I see during compilation: > [snips] > I think this is fixed now in the trunk. Could you verify, please? Hello, I've just built and installed Boost from the trunk, but this conflict remains - lots of compilation errors. Regards, Artem

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boost filesystem library files can not be linked
by Peng Yu 14 Jun '10

14 Jun '10

My ubuntu is 10.04. boost was installed from apt-get. I compiled the following code. But the library is not available to link. Would you please let me know how what link option I should use? $ cat main.cpp #include <boost/filesystem.hpp> #include <iostream> #include <string> int main() { boost::filesystem::path path1("/tmp/dir1/test1.c "); boost::filesystem::path path2("/tmp/dir1/.test1.profile"); std::string result1 = boost::filesystem::basename (path1); std::string result2 = boost::filesystem::basename (path2); std::cout << result1 << std::endl; std::cout << result2 << std::endl; return 0; } $g++ -o main.exe main.cpp /tmp/ccSvyGYq.o: In function `__static_initialization_and_destruction_0(int, int)': main.cpp:(.text+0x15d): undefined reference to `boost::system::get_system_category()' main.cpp:(.text+0x169): undefined reference to `boost::system::get_generic_category()' main.cpp:(.text+0x175): undefined reference to `boost::system::get_generic_category()' main.cpp:(.text+0x181): undefined reference to `boost::system::get_generic_category()' main.cpp:(.text+0x18d): undefined reference to `boost::system::get_system_category()' collect2: ld returned 1 exit status make: *** [main.exe] Error 1 -- Regards, Peng

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[asio] Can deadline_timer and setitimer() coexist?
by Nader Salehi 14 Jun '10

14 Jun '10

Hi, I was wondering if we could use setitimer() in a code base that utilizes ASIO deadline_timer? I have a server code which uses ASIO for various async operations --including a few async timers. It uses io_service.run() in the main function to dispatch events. The server needs to gracefully shutdown, meaning that it should finish all the currently queue events. As an upper bound to the graceful shutdown, I want to set a timer to guarantee the code will exit. Adding the timer, howerver, as an ASIO deadline_timer will force the run() function to wait until the shutdown timer expires. Using setitimer() and handling SIGALRM looks like a better alternative for me. I think it works, but I need to know whether there is no side effect to this. Thanks, Nader PS. NO, I cannot use io_service.run_one() :)

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[serialization] JSON Archives
by Fernando Pelliccioni 14 Jun '10

14 Jun '10

Hi, After experimenting with Spirit.Qi to make a JSON parser, I had the need for a serializer. First, I thought I could serialize my model of JSON (json:: value, json: object, etc.), but that was not compatible with boost::serialization. I am currently writing a ARCHIVE for Boost Serialization, but I'm finding some problems in order to implement JSON correctly. The question is, does anyone know about some files to Boost Serialization already finished? I've seen the Archive made by Esteve Fernandez, but do not serve my purpose, because I just need JSON. I would like to develop a JSON parser which in turn is a compatible Boost Serialization serializer . Any ideas? Thanks and regards, Fernando Pelliccioni.

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[Filesystem] issues with get_full_path_name_template on Win32
by John Dlugosz 14 Jun '10

14 Jun '10

Looking at operations.cpp, the function get_full_path_name_template has a couple minor issues that could use improvement. First, the original buffer size used in 128. A value of _MAX_PATH (which is 260) + 1 for the trailing nul would prevent the need to iterate, except in unusual cases. The code adds a nul terminator with buf[len]='\0' or big_buf[len]='\0', but the underlying GetFullPathName call already nul-terminated the string. It bugs me that big_buf[len] is used without checking that the new value of len is OK, and that the char form of the literal is used. Removing these statements would avoid both issues. In the past, I've found some APIs that don't record the desired length correctly, so I've learned to be more defensive and give a little extra padding rather than the exact amount specified. The specific bug I've found in Windows concerned the character set conversion code, which takes more space for intermediate results than for the final result. They are also known for being inconsistent about counting or not counting the trailing nul. In my own code, I dealt with "\\?\" specially. Any time the string begins with "\\" (two actual backslashes) it is either a UNC name or this special escape prefix, so the function is a no-op. The documentation for GetFullPathName says that it handles UNC names, and one of the examples is taking the escape prefix. But the reason for using the prefix is to get around length limits and avoid automatic processing of the name, so just shorting out and returning the input unchanged will avoid the big_buf stuff and prevent any accidental unwanted alteration. --John (huge company footer follows) TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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[Asio] ssl socket server example wont work
by Jan Dinger 14 Jun '10

14 Jun '10

Hello folks, I've been to test the boost asio ssl socket example: http://www.boost.org/doc/libs/1_43_0/doc/html/boost_asio/example/ssl/server… The code is copy & paste. The program compiled without problems, if I start the program I became an exception: ### snip ### Exception: Invalid argument ### snap ### While I'm debugging the program I find out the error throws in the following lines... ### snip ### context_.set_options( boost::asio::ssl::context::default_workarounds | boost::asio::ssl::context::no_sslv2 | boost::asio::ssl::context::single_dh_use); context_.set_password_callback(boost::bind(&server::get_password, this)); context_.use_certificate_chain_file("ca_cert.pem"); context_.use_private_key_file("ca_cert.pem", boost::asio::ssl::context::pem); context_.use_tmp_dh_file("dh512.pem"); ### snap ### I can't locate the error exactly, could it be I've created my certificates with wrong steps? Here is the code, I've created my certificates. Root Certificate ### snip ### openssl req -new -x509 -keyout ssl_priv.pem -out ca_cert.pem -days 3650 ### snap ### Diffie-Hellmann ### snip ### openssl dhparam -out dh1024.pem 512 ### snap ### I've linked the required boost libraries and the OpenSSL Library... Whats going wrong, can everyone help me? Thanks. so long jd

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[Filesystem] questions
by John Dlugosz 14 Jun '10

14 Jun '10

I'm trying to replace my use of native file-path manipulations with the Filesystem TR2 candidate library, in preparation to advocating the use of this library as proper style instead of home-grown wrappers everywhere. However, I still have questions on some of the things I ran into in this simple usage: 1) I call remove (p,ec); and get a compile-time error that no form takes two arguments. Looking in the header, that seems to be the case. The Filesystem Reference (<http://www.boost.org/doc/libs/1_43_0/libs/filesystem/doc/reference.html>) clearly shows an error code parameter. I understand this module is tracking the standardization process. So which is newer? Should I be anticipating the code change to match the docs, or vice versa? How do I find out if there was an error and report the details? Note that I want to consider the case of the file not existing in the first place as OK. 2) The documentation shows things like: template <class Path> bool remove(const Path& p, system::error_code & ec = singular ); * if ec != singular, then ec.clear(). I can't find any definition for 'singular'. What is it? Besides acting as a flag to know if the argument was defaulted, it seems like it's doing some kind of one-shot behavior? 3) The basic_path constructor that takes two InputIterators: what kind of iterator is that? It doesn't seem to want characters, but an iterator of parts like produced by the begin/end functions. But the iterator's underlying type is not defined, so you can't make your own collection of "parts". So why doesn't the constructor just take its own iterator type, but is a template? What else could you give it? The documentation is not clear. TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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