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[boost-install]update old version to new one by 'bjam install'
by hongleij 10 Oct '10

10 Oct '10

i have install 1.43 version in my system,after use “./bjam install” to intall boost1.44,i met the following error. [root@localhost gridcast]# g++ -o datetime datetime_tcp_async_server.cpp -lpthread -lboost_system -L/usr/local/lib datetime_tcp_async_server.cpp:142:2: 警告：文件未以空白行结束 /tmp/ccjG0R2d.o: In function `__static_initialization_and_destruction_0(int, int)': datetime_tcp_async_server.cpp:(.text+0x16c): undefined reference to `boost::system::get_system_category()' datetime_tcp_async_server.cpp:(.text+0x176): undefined reference to `boost::system::get_generic_category()' datetime_tcp_async_server.cpp:(.text+0x180): undefined reference to `boost::system::get_generic_category()' datetime_tcp_async_server.cpp:(.text+0x18a): undefined reference to `boost::system::get_generic_category()' datetime_tcp_async_server.cpp:(.text+0x194): undefined reference to `boost::system::get_system_category()' /tmp/ccjG0R2d.o: In function `boost::asio::error::get_system_category()': datetime_tcp_async_server.cpp:(.text._ZN5boost4asio5error19get_system_categoryEv[boost::asio::error::get_system_category()]+0x7): undefined reference to `boost::system::get_system_category()' /tmp/ccjG0R2d.o: In function `boost::system::error_code::error_code()': datetime_tcp_async_server.cpp:(.text._ZN5boost6system10error_codeC1Ev[boost::system::error_code::error_code()]+0x10):undefined reference to `boost::system::get_system_category()' collect2: ld 返回 1 so i delete /usr/local/include/boost dir ,and rerun ”./bjam install” -bash-3.2# g++ datetime_tcp_async_server.cpp -lpthread datetime_tcp_async_server.cpp:142:2: warning: no newline at end of file /tmp/ccQeKssV.o: In function `__static_initialization_and_destruction_0(int, int)': datetime_tcp_async_server.cpp:(.text+0x176): undefined reference to `boost::system::generic_category()' datetime_tcp_async_server.cpp:(.text+0x182): undefined reference to `boost::system::generic_category()' datetime_tcp_async_server.cpp:(.text+0x18e): undefined reference to `boost::system::system_category()' /tmp/ccQeKssV.o: In function `boost::system::get_system_category()': datetime_tcp_async_server.cpp:(.text._ZN5boost6system19get_system_categoryEv[boost::system::get_system_category()]+0x5): undefined reference to `boost::system::system_category()' /tmp/ccQeKssV.o: In function `boost::system::error_code::error_code()': datetime_tcp_async_server.cpp:(.text._ZN5boost6system10error_codeC1Ev[boost::system::error_code::error_code()]+0x17): undefined reference to `boost::system::system_category()' collect2: ld returned 1 exit status --------------------------------- the name changed from `boost::system::get_generic_category()' to `boost::system::generic_category()',so it seems if i already have an old version of boost,i need remove it clearly to reinstall the new one by myself.

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[boost.datetime] query
by Sean Farrow 10 Oct '10

10 Oct '10

Hi: Is it possible to return a number representing the date. Like you can with COleDateTime.m_dt; Any help appreciated. Regards Sean.

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[asio] How to get informed about failed connection attempts?
by for-gmane 10 Oct '10

10 Oct '10

The following code (from the examples) accepts a connection and calls the handler handle_accept(). But it calls the handler only if the connection attempt (internally) succeeds. The handler gets not called if the connection fails (for example when an ssl-connection-attempt fails due to wrong keys etc.). What should I do to get informed also about such failed connection attempts? acceptor_.async_accept(new_session->socket(), boost::bind(&server::handle_accept, this, new_session, boost::asio::placeholders::error));

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Memory usage
by Olivier Tournaire 10 Oct '10

10 Oct '10

Hi all, Is there a (portable) way with boost libs to check memory usage? Best regards, Olivier

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Http Server 3 example with SSL, ie. https
by for-gmane 09 Oct '10

09 Oct '10

Hi, has anybody extended the Http Server 3 example with SSL, ie. https? Are there any other simple https-server examples based on asio?

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AIX large file support
by Will Mason 09 Oct '10

09 Oct '10

Hello, I'm using Boost 1.42, IBM XL C++ 10.1, and AIX 5.3. On AIX the way to enable large file support is to define _LARGE_FILES on the compiler command line. When I attempt to build Boost with this definition, I see errors like the following: "/home/wmason/src/cap-aix/fim/../opt/include/aix/boost/v1.42/boost/date_time/date_parsing.hpp", line 50.21: 1540-0215 (S) The wrong number of arguments have been specified for "tolower(int)". This causes catastrophic failure of Boost to build. Fortunately, by poking around the sources I found that I can enable large file support in Boost on AIX with IBM's compiler by defining _LARGEFILE64_SOURCE. Although this bypasses IBM's recommended way of enabling large file support, it does work to build Boost with large file support. The problem is that my product enables large file support the normal way, which leads me back to the above error when I try to build. I could just manually enable large file support in my code, but this causes portability problems. Not all operating systems support large files the same way, so trying to do it manually on every system will be a headache. Our portability strategy involves enabling large file support the normal way on every system, which in many cases, including AIX's, involves defining things on the command line. Is there any way to use normal large file support on AIX and not have Boost go down in flames? Thanks very much for any help, Will

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[proto] Can't use template domain class with BOOST_PROTO_BASIC_EXTENDS
by joel falcou 09 Oct '10

09 Oct '10

Trying to use template domain class with BOOST_PROTO_BASIC_EXTENDS ends up in an error leading to the fact this ligne in the macro is incorrect when the Domain is template: BOOST_PROTO_BASIC_EXTENDS_(Expr, Derived, Domain) typedef void proto_is_aggregate_; typedef Domain::proto_generator proto_generator; Obviously this is alckign a typename before Domain::proto_generator if Domain is actually a template class. Thing is used to work before ( aorund 1.40) so I guess somethign changed around here. I guess a details meta-function extracting the domain will fix that or am I wrong ? namespace boost { namespace proto { template<class Domain> generator_of { typedef typename Domain::proto_generator type; }; } } BOOST_PROTO_BASIC_EXTENDS_(Expr, Derived, Domain) typedef void proto_is_aggregate_; typedef typename generator_of<Domain>::type proto_generator; Or is it ?

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[variant][any] template parameterized variant
by alfC 09 Oct '10

09 Oct '10

Hi, I need a variant type object that can hold any type characterized by a template. For example Boost.Units have a family of types parameterized by "System". quantity< unit<dimension, System>, double> suppose dimension is fixed, e.g. typedef boost::units::length dimension is it possible to define a variant over that family of types? I could create a make_variant_over< list of all types > but that can be that list will be fixed and each time I defined a new System the list will have to grow. to simplify the question: template<class T> class dummy{ ... }; variant< "dummy<T>" > v; //for all T If it simplifies things, suppose that all dummy<T> have the same sizeof and that all are convertible to each other. Or should I be using an extension of boost::any with some adhoc restriction over the possible types on construction? Thank you, Alfredo

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[fusion] .at<N>() template member in containers?
by alfC 09 Oct '10

09 Oct '10

Hi, Excuse my simple minded questions. Sometimes by asking this question (often with negative answer) I understand more on the design of the Boost libraries. Besides possible redundancy, why is that the fusion containers, for example fusion::vector, doesn't have a template member function to extract elements? fusion::vector<double, int, std::string> stuff(1.2, 3, "hola"); stuff.at<2>(); //returns "hola", just like at_c<2>(stuff); Wouldn't it be more consistent with std::vector v, v[2] or v.at(2); By the way, does anybody know where the name given "at_c" (I mean the '_c') comes from? Thank you, Alfredo

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boost/preprocessor checking if argument is a constant
by Z S 09 Oct '10

09 Oct '10

All the BOOST_PP functions only work on integer constants. I want to write macros, where the same interface can be used for both constants and variables, and only call the BOOST_PP if the argument is a constant, and use runtime code if it is a variable. For example, #define TWICE(n) BOOST_PP_IF( _IS_CONSTANT(n), \ BOOST_PP_MUL(n,2), \ ( (n) * 2) ) For more details, you can also see the original question here : http://stackoverflow.com/questions/3884489/mixing-variables-and-integer-con… Is there a way to do so? The C preprocessor knows whether something is a constant, so we should be able to do this somehow. Or should I suggest this as a feature request for the Boost Preprocessor library? Thanks!

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