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[ublast] sparse matrix - resize with preserve
by Olivier Jouny 24 Jan '08

24 Jan '08

I would like to use the resize method of mapped_matrix with preserve = true but it does not work. By looking at the implementation, a comment says not implemented :-( Can you confirm ? If it's the case, does somebody has a work around ? Regards, Olivier. _________________________________________________________________ Comme 9 millions de français, créez un compte Hotmail ! http://www.windowslive.fr/hotmail/default.asp

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Storing types in a non-template class?
by Robert Dailey 24 Jan '08

24 Jan '08

Hi, I have a singleton class called InputRegistry. Before the class is used, the user must call: InputRegistry::Initialize(); I would like this function to take a parameter that defines the type of a critical section object, which is unknown at compile time (template). I need to store this type in my InputRegistry class so that the unknown critical section type can be constructed later. How can I do this without making InputRegistry a template class? If I make InputRegistry a template, that basically means I need to redesign the class, as the singleton pattern would not apply if it were a template class. I'm hoping boost can help here. Thanks in advance.

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[Singleton] pre-review question
by Ovanes Markarian 24 Jan '08

24 Jan '08

Hello, I am currently evaluating boost.singleton for our application. I hope it is not too late to write a review. As I understood from the docs, Singleton instance is immediately (when all global and static variables are initilized) created. In our context we need singleton to be created on first request (as it is described in GoF). The problem is following: Our application must parse config file which is accessible after entering main and store the options/parameters parsed in a singleton class. If I initialize singleton immediately (before entering main) I can not parse command line options and have to trick around with some additional functions which do it for me (but a constructor would be a much better choice, when I try for the first time to access the singleton). Is that possible with the current implementation? I know I could overload operator-> and check that options are parsed, but I think this is a not so obvious scenario for everyone. With Kind Regards, Ovanes

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cygwin buit boost libraries do not work
by Steven Woody 24 Jan '08

24 Jan '08

Hi folks, I have buit boost in cygwin followed instruction in the boost getting start documentation. it seemed successful and many libraries ( including dynamic and static ones ) were put into /usr/local/lib. I then try to compile a very simple example code listed as blow, which are a copy on the boost documentaion. #include <boost/regex.hpp> #include <iostream> #include <string> int main() { std::string line; boost::regex pat( "^Subject: (Re: |Aw: )*(.*)" ); while (std::cin) { std::getline(std::cin, line); boost::smatch matches; if (boost::regex_match(line, matches, pat)) std::cout << matches[2] << std::endl; } } What I did is, g++ -I/usr/local/include RegexSample.cpp -o RegexSample -L/usr/local/lib -lboost_regex but the resulting RegexSample.exe can not run properly -- it simply exist with an error code ( 53 ) and do nothing for me. My question is: is there anything different for Boost on Cygwin? The procedure I used to buid Boost on Cygwin is provided as below. Please check it can tell me if there is anything wrong. Thanks! --------- 1, build the bjam using './build.sh gcc' under the tools/jam/src directory and then copy bjam.exe to a place searchable; 2. 'bjam --builddir=~/tmp --toolset=gcc --layout=system --without-python install' ----------- -- woody then sun rose thinly from the sea and the old man could see the other boats, low on the water and well in toward the shore, spread out across the current.

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Re: [Boost-users] Multiple templates singletons
by Hicham Mouline 24 Jan '08

24 Jan '08

I omited to show the definition of those templates TreeImplBase.They would have the map as a private member,as protected members, functions to insert instances in the map, called by the ctors of derived templates. I will look at boost::fusion thanks, ----- Original Message ----- From: "Ovanes Markarian" To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Multiple templates singletons Date: Thu, 24 Jan 2008 00:02:01 +0100 Hello! I have a question to this construct: template <typename contractType, typename treeType> class TreeImplBase; Each specialization of these holds a static std::map< boost::tuple<int,enum1,enum2,enum3>, const TreeImplBase* >; which contains the list of the derived template classes. How can you instantiate a pointer to the class temlate? Class template is an incomplete type. You will not be able to specify a pointer to it. I think you should use boost::fusion inplace. This lib, offers a compile time map (if you map the same time to an instance of it, use a fusion set), which can map a type to an instance. This is what you need. http://spirit.sourceforge.net/dl_more/fusion_v2/libs/fusion/doc/html/fusion… http://spirit.sourceforge.net/dl_more/fusion_v2/libs/fusion/doc/html/fusion… Any comments are appreciated, Perhaps this is a known design pattern, perhaps there is an easier way of doing this, perhaps there is a boost library which helps with this, Good Luck, Ovanes _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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iostreams and serial ports help
by Rob Desbois 24 Jan '08

24 Jan '08

Hi, I'm a newcomer to boost and having trouble determining if what I want to achieve is possible. I want some sort of boost::iostreams object wrapping a serial port so that it conforms to the usual interfaces - this would be extremely useful not only for its use, but also to enable injection of a stringstream instance as a mock object when testing. It seems that the likely candidate for this is file_descriptor but I'm not entirely sure. First off, file_descriptor refines SeekableDevice, which a serial port isn't - does this mean that I can't do it? After trying to compile I realised that a SeekableDevice provides read, write and seek functions, nothing else. Am I seriously misunderstanding the point of boost::iostreams? If I am then can anybody point me in a better direction? My ultimate requirement is a serial port access class that looks just like a C++/boost iostream. I cannot use C++ iostreams directly as I require access to file-descriptor which is not available. Anyone able to help a lost person please? TIA, --rob

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[function] using with CRTP
by Russell L. Carter 23 Jan '08

23 Jan '08

Hi, This is probably a novice template question. I am curious what I am doing wrong here, where I'm trying to get a function object holding a base member of a CRTP class. gcc 4.2.3 complains about: type/value mismatch at argument 1 in template parameter list for 'template<class Derived> template<template<template<class> class MHBase> template<class Derived> template<class> class MHBase> struct MHBase< <template-parameter-1-1> >::fooFO Any help appreciated! Thanks, Russell #include <boost/function.hpp> #include <iostream> class MHBAccessor { template<class> friend class MHBase; template<class Derived> static int foo(Derived& derived, int i) { return derived.foo_(i); } }; typedef boost::function<int (int)> FooFunc; template <class Derived> struct MHBase { Derived& derived() { return static_cast<Derived&>(*this); } int foo(int i) { return MHBAccessor::foo(this->derived(), i); } template <template <class> class MHBase > struct fooFO { fooFO(MHBase<Derived>& mhb) : mhb_(mhb) {} void operator()(int i) { mhb_.foo(i); } private: MHBase<Derived>& mhb_; }; FooFunc getFooFunc() { FooFunc ff = fooFO<MHBase<Derived> >(*this); return ff; } }; class Put : public MHBase<Put> { friend class MHBAccessor; int foo_(int i) { return i; } }; int main(int argc, char **argv) { Put put; std::cout << put.foo(123) << std::endl; FooFunc ff = put.getFooFunc(); std::cout << ff(456) << std::endl; return 0; }

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iostreams::stream: flush doesn't work but endl does
by Rob Desbois 23 Jan '08

23 Jan '08

Hi all, I've created my own iostreams device (for a serial port) which for debugging purposes prints out calls to read()/write(). I'm constructing a stream on the device like this: serial_device serial("/dev/ttyS3", serial_device::Baud38400); stream<serial_device> s(serial); If I do this: s << "hello world" << endl; serial.write() is called and does its debug output, but with this: s << "hello world\r" << flush; I get nothing despite using 'flush'. I've also tried calling s.flush() manually but get the same lack of effect. How come flush isn't working as it should here? TIA, --rob -- Rob Desbois

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Solve linear system (tridiagonal matrix)
by nisha kannookadan 23 Jan '08

23 Jan '08

Hi everybody I need to solve a linear system Ax = b, where A is a tridiagonal matrix, is there an easy way to do it? I programmed an algo, which computes the inverse of the tridiagonal matrix with the usmani-algo and uses prod then, but this is quite time intense. I want to use the lapack bindings, but I dont get along with it. Im bit confused, if I need to install something additional to it, the way I tried out gesv, its not working and I get error msgs. I searched through out the www, but its hard to find good info. If somebody has already the code to solve linear equations with lapack, I would thankful, if he could post it here. Thank you Nisha K _________________________________________________________________ Express yourself instantly with MSN Messenger! Download today it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/

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Property Tree
by Glasgow, Craig C 23 Jan '08

23 Jan '08

Hello I'm using boost property_tree with the variant data type: typedef boost::variant<std::string, std::vector<std::string> > registry_entry; i.e I want to store either strings or vectors of strings at each key node. I'm using the inserters and extractors at the bottom of this email (similar to those included in the custom_data.cpp in the property_tree/examples folder). Does anyone know how I can write the tree out in xml format? The provided write_xml method can only handle property trees of string data type. Is there anyway to either tweak the code (e.g. modify the inserter and extractors) or wrap the variant class such that property_tree::write_xml will correctly render the tree as xml? Regards Craig // Custom extractor - converts data from boost::any to Type template<class Type> struct pt_extractor { inline bool operator()(const boost::any &data, Type &extracted, const std::locale &loc) const { extracted = boost::any_cast<Type>(data); return true; // Success } }; // Custom inserter - converts data from Type to boost::any template<class Type> struct pt_inserter { inline bool operator()(boost::any &data, const Type &to_insert, const std::locale &loc) const { data = to_insert; return true; // Success } }; // Custom property_tree traits - using custom extractor and inserter template<class Ch> struct pt_traits { // Character type to be used by ptree keys typedef Ch char_type; // Key type to be used by ptree typedef std::basic_string<Ch> key_type; // Data type to be used by ptree typedef boost::any data_type; // Extractor to be used by ptree template<class Type> struct extractor: public pt_extractor<Type> { }; // Inserter to be used by ptree template<class Type> struct inserter: public pt_inserter<Type> { }; // Key comparison function inline bool operator()(const key_type &key1, const key_type &key2) const { return _stricmp(key1.c_str(), key2.c_str()) < 0; } }; typedef boost::property_tree::basic_ptree<pt_traits<char> > pt_rep; typedef boost::variant<std::string, std::vector<std::string> > registry_entry; ***************************************************************************** This communication is sent by the Standard Bank Plc or one of its affiliates The registered details of Standard Bank Plc are: Registered in England No. 2130447, Registered Office 25 Dowgate Hill London EC4R 2SB Authorised and Regulated by the Financial Services Authority. More information on Standard Bank is available at www.standardbank.com Everything in this email and any attachments relating to the official business of Standard Bank Group Limited and any or all subsidiaries, the Company, is proprietary to the Company. It is confidential, legally privileged and protected by relevant laws. The Company does not own and endorse any other content. Views and opinions are those of the sender unless clearly stated as being that of the Company. The person or persons addressed in this email are the sole authorised recipient. Please notify the sender immediately if it has unintentionally, or inadvertently reached you and do not read, disclose or use the content in any way and delete this e-mail from your system. The Company cannot ensure that the integrity of this email has beenmaintained nor that it is free of errors, virus, interception or interference. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. This message is provided for informational purposes and should not be construed as a solicitation or offer to buy or sell any securities or related financial instruments. *****************************************************************************

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