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Singleton
by Jason Hise 13 Jan '05

13 Jan '05

I have a question about the longevity lifetime. Does such a lifetime only manage destruction order, or should it also manage order of creation? The way I'm currently implementing my longevity lifetime policy, there would be a master function in the LongevityManagerSingleton which would set the 'creation level'. This would basically create singletons up to this level or destroy them down to this level, so that all singletons at a given level could be assured that singletons with a smaller longevity number existed for their entire lifetime. Example: A has longevity 0, B = 1, C = 2, D = 3, E = 4 Upon setting the creation level to 3, A would be created, then B, then C, then D. Subsequently setting the creation level to 1 would destroy D, then destroy C. Is this anything like what the users of a longevity lifetime would like, or am I completely off track here? -Jason

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RFC: mixing std::map and boost::optional
by Ulrich Eckhardt 13 Jan '05

13 Jan '05

I had the idea to use boost::optional on the interface of a std::map-like object. I have neither coded a prototype nor is this a fully grown design yet, I'd just like to discuss this idea. The rough outline is this: class my_map { public: optional<value>& operator[](key const&); optional<value> const& operator[](key const&) const; // iterators, ctors, dtor, etc the same private: optional<value> const m_empty_value; tree< pair<key, optional<value> > > m_content; }; The important differences to std::map are: 1. operator[] is available as const and non-const memberfunction. The const memberfunction returns 'm_empty_value' in case the key is not found. The non-const one inserts a new node into the tree and returns a reference to that. 2. operator[] return an optional<value>, not a direct value. This means that you have to check the return-value of this call. OTOH, you _can_ check the return value to see if a key was associated with a value. Some example code, compared with the equivalents using std::map: // two maps std::map<string,float> stdmap; my_map<string,float> mymap; // const references, for cases where it makes a difference std::map<string,float> const& stdmapc = stdmap; my_map<string,float> const& mymapc = mymap; ///////// inserting an element: stdmap["key"] = 41.0f; mymap["key"].reset(42.0f); ///////// accessing an element access(stdmap["key"]); std::map<string,float>::const_iterator it = stdmapc.find("key"); if(it!=stdmapc.end()) access(it->second); else access(float()); boost::optional<float>& value = mymap["key"]; if(value) access(*value); else access(float()); boost::optional<float> const& value = mymap["key"]; if(value) access(*value); else access(float()); ///////// removing an element stdmap.erase("key"); mymap["key"].reset(); ///////// finding out if an element exists if(stdmap.find("key") != stdmap.end()) found(); if(mymap["key"]) found(); ///////// iterating and accessing for(std::map<string,float>::const_iterator it=stdmap.begin(); it!=stdmap.end(); ++it) access(it->second); for(my_map<string,float>::const_iterator it=mymap.begin(); it!=mymap.end(); ++it) if(it->second) access(*(it->second));

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Sealed/Final implementation.
by kalin 13 Jan '05

13 Jan '05

Hi All, I've made a simple implementation of making a class non-derivable. Aside from the pros/cons of actually using this, which I'm sure could be debated for months, I thought I'd present the implementation anyway to see if there is interest in it. I thought something like this might already be in Boost, but I couldn't locate it, or any threads about the subject. Usage is as: class Foo : Sealed<Foo> {}; class Bar : Foo {}; // Error. And it should all work as intended (unless I've missed something) and not allow you to instantiate Bar. --- Implementation --- namespace Detail { template <class T, class Parent> class Sealed { friend T; friend Parent; }; } template <class T> class Sealed : public virtual Detail::Sealed<T, Sealed> { friend T; }; --- kalin

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boost.test covered in testing frameworks rundown
by Max Khesin 13 Jan '05

13 Jan '05

http://www.gamesfromwithin.com/articles/0412/000061.html Well, some good marks but no victory. Perhaps the people involved in the library will find this useful. cheers, max This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail.

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Linking w/ Boost 1.3.2 and STLport 4.6.2
by Aleksandar Fabijanic 13 Jan '05

13 Jan '05

Hello, I'm having problems comiling linking with Bosst and STLport. Development environment is Visual Studio .NET 2003. I am building Boost like this: C:\Projects\boost\boost_1_32_0>bjam -sTOOLS="vc-7_1-stlport" -sBUILD="<stlport-iostream>on" -sBUILD="<native-wchar_t>on" stage C:\Projects\boost\boost_1_32_0>bjam -sTOOLS="vc-7_1-stlport" -sBUILD="<stlport-iostream>on" -sBUILD="<native-wchar_t>on" install This builds and creates C:\Boost\... inlcude and lib dirs. When I try to include <boost/thread/thread.hpp> from my app, I am encountering following problems: Debug: warning: STLPort debug versions are built with /D_STLP_DEBUG=1 c:\Boost\include\boost-1_32\boost\config\auto_link.hpp(206) : fatal error C1189: #error : "Build options aren't compatible with pre-built libraries" Release: Linking... LINK : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/OPT:ICF' specification LINK : fatal error LNK1104: cannot open file 'libboost_thread-vc71-mt-sp-1_32.lib' I have libboost_thread-vc71-mt-sgdp.lib What bjam options do I use to build Boost so it compiles in Debug and produces the library name linker is looking for in Release? Any help will be appreciated. Thanks in advance. Alex __________________________________ Do you Yahoo!? The all-new My Yahoo! - What will yours do? http://my.yahoo.com

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[test] CHECK_EQUAL and problem with class constants
by Jody Hagins 13 Jan '05

13 Jan '05

Consider this simple example... #include <boost/test/test_tools.hpp> struct Foo { static unsigned int const x = 10; }; int test_main( int, char* [] ) // note the name! { BOOST_CHECK_EQUAL(10U, Foo::x); return 0; } At least under gcc, I get a linker error, unable to find Foo::x, while the following code works fine... int test_main( int, char* [] ) // note the name! { BOOST_CHECK(10U == Foo::x); return 0; }

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[date_time] serialization of ptime with bcc32-5.6.4
by Russell Hind 13 Jan '05

13 Jan '05

I'm trying to serialize a ptime to an xml archive. I've included boost/date_time/posix_time/time_serialize.hpp but get an ambiguity error: [C++ Error] serialization.hpp(121): E2015 Ambiguity between 'boost::serialization::void serialize<boost::archive::xml_iarchive>(boost::archive::xml_iarchive &,boost::posix_time::ptime &,const unsigned int)' and 'boost::serialization::void serialize<boost::archive::xml_iarchive,boost::posix_time::ptime>(boost::archive::xml_iarchive &,boost::posix_time::ptime &,const unsigned int)' Is this a problem with the compiler or should this work? Thanks Russell

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[test] Detecting timeout support
by Jody Hagins 13 Jan '05

13 Jan '05

The example, unit_test_example2.cpp, demonstrates the detection of a timeout... void infinite_loop() { // unit test framework can break infinite loops by timeout #ifdef __unix // don't have timeout on other platforms BOOST_CHECKPOINT("About to enter an infinite loop!"); while(1); #else BOOST_MESSAGE( "Timeout support is not implemented on your platform" ); #endif } In my tests, I'd rather not have #ifdef __unix all over the place. Is is possible to add a macro in the Test framework itself that can be checked (on the off chance that timeout support is expanded)?

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building boost 1.32 library under vc7.1 with _fastcall
by Alex Baskakov 13 Jan '05

13 Jan '05

How are you, boost? I'm using /Gr option in my project under vc7.1 (the __fastcall calling convention for all functions except C++ member functions and functions marked __cdecl or __stdcall) And I'm trying to build boost with /Gr option but there are some troubles, for example, with Boost.Test library (it define 'main' function without __cdecl) So, what is the right way to do that? Is it possible to use boost in another calling vc7.1 conventions? Bye.

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build with specific python exec
by Neal Becker 13 Jan '05

13 Jan '05

I want to build using a python installed as "python24". How can I do this?

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