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RE: [boost] Re: Thread lib (good reason for static)
by Hurd, Matthew 09 Jun '04

09 Jun '04

> Behalf Of scott > Assume use of a technique like the following (think this has been > presented as "object shim"?); > > T & > anastasia() > { > static T *p = new T; > return *p; > } > > as a means of dealing with global construction issue, i.e. instead > of expressions like "anastasia.data_member" the usage is > "anastasia().data_member". Also assume that some of these global > objects (i.e. shims) deploy mutexes for MT reasons. What happens > when there is more that one thread running around making calls > to shims? Instantiation of the global itself becomes an MT issue. That's what the double-checked locking pattern for singletons is for. Regards, Matt Hurd. _______________ Matt Hurd +61.2.8226.5029 hurdm(a)sig.com Susquehanna _______________ IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.

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regression test tools ported to vacpp
by Toon Knapen 09 Jun '04

09 Jun '04

The regression test tools are finally ported to vacpp version 6 and the regression test status will again be updated every day at 6am CET (unless new changes break the compilation again). Please don't hesitate to contact me when you want some help porting your boost library to the IBM/VisualAge platform. toon

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CVS temporarily disabled
by David Abrahams 09 Jun '04

09 Jun '04

http://sourceforge.net/docman/display_doc.php?docid=2352&group_id=1#1086711… ( 2004-06-08 09:17:17 - Project CVS Service ) As of 2004-06-08 at 09:16 Pacific, developer CVS services have been disabled for some unplanned maintenance. We do not currently have an ETA for the duration of this outage but we do hope to minimize it as much as possible. -- Dave Abrahams Boost Consulting http://www.boost-consulting.com

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RE: [boost] Re: Thread lib (good reason for static)
by Hurd, Matthew 09 Jun '04

09 Jun '04

> Behalf Of Eric Niebler > Sent: Wednesday, 9 June 2004 9:15 AM > To: boost(a)lists.boost.org > Subject: [boost] Re: Thread lib (good reason for static) > > Hurd, Matthew wrote: > >>Behalf Of scott > >>Assume use of a technique like the following (think this has been > >>presented as "object shim"?); > >> > >>T & > >>anastasia() > >>{ > >> static T *p = new T; > >> return *p; > >>} > >> > >>as a means of dealing with global construction issue, i.e. instead > >>of expressions like "anastasia.data_member" the usage is > >>"anastasia().data_member". Also assume that some of these global > >>objects (i.e. shims) deploy mutexes for MT reasons. What happens > >>when there is more that one thread running around making calls > >>to shims? Instantiation of the global itself becomes an MT issue. > > > > > > That's what the double-checked locking pattern for singletons is for. > > > > Regards, > > > > Matt Hurd. > > > No, the double-checked locking pattern is only good as the subject of > talks describing why it's not good for anything. > > http://www.nwcpp.org/Downloads/2004/DCLP_notes.pdf Thanks. They are good notes. I'm aware of the portability issues. Doesn't mean you can't have valid platform specific singleton implementations that use the double checked locking pattern. The performance of the approach is too important to give up. Locking is slow. There are a lot of things you can't do portability in C++ which is one rationale for having libraries :-) Regards, Matt Hurd. _______________ Matt Hurd +61.2.8226.5029 hurdm(a)sig.com Susquehanna _______________ IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.

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boost::any question
by Trey Jackson 08 Jun '04

08 Jun '04

All, I just started looking at boost::any, pretty nice. I looked at the implementation, and it uses (as you know) a pointer to an object (w/virtual methods) on the heap, and typeid to determine if conversion is possible. I understand the memory implications (a new object copied on heap). But I'd like to get a better handle on performance, namely: I'm unfamiliar with typeid - and how it's implemented. Does anyone have good pointers to how typeid is generally implemented? Or even specifically: I'm using gcc3.x on RH Linux. I'd just like to avoid/guarantee I'm not going to be hit by some O(N) look-up for using typeid a lot. thanks, TJ -- Trey Jackson tjackson(a)ichips.intel.com "Her hair glistened in the rain like nose hair after a sneeze." -- Chuck Smith, Woodbridge

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Problem with mpl::iter_fold_if.hpp in vacpp 6.0
by Joaquín Mª López Muñoz 08 Jun '04

08 Jun '04

Regression tests show the following at different locations: "/home/tk/boost_regression/boost/boost/mpl/iter_fold_if.hpp", line 104.11: 1540-0038 (S) The name "typename result_::state" is not a type. I don't know how easy to fix this can be (for those who know the internals of MPL). Currently, the problem breaks uBLAS and multi_index. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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Problem building bjam executable
by Bart Garst 08 Jun '04

08 Jun '04

I'm trying to build the bjam executable by running build.bat from the boost/tools/build/jam_src directory. Here's what I get: C:\BOOST\TOOLS\BUILD\JAM_SRC>build.bat vc7 ### ### "Unknown toolset: vc7" ### ### You can specify the toolset as the argument, i.e.: ### .\build.bat msvc ### ### Toolsets supported by this script are: borland, como, gcc, gcc-nocygwin, intel-win32, metrowerks, mingw, msvc, vc7 ### I also tried running vcvars32 prior to build.bat and got this: C:\BOOST\TOOLS\BUILD\JAM_SRC>"e:\program files\microsoft visual studio .net\vc7\bin\vcvars32" C:\BOOST\TOOLS\BUILD\JAM_SRC>"E:\Program Files\Microsoft Visual Studio .NET\Common7\Tools\"vsvars32.bat Setting environment for using Microsoft Visual Studio .NET tools. (If you also have Visual C++ 6.0 installed and wish to use its tools from the command line, run vcvars32.bat for Visual C++ 6.0.) C:\BOOST\TOOLS\BUILD\JAM_SRC>build.bat vc7 Setting environment for using Microsoft Visual Studio .NET tools. (If you also have Visual C++ 6.0 installed and wish to use its tools from the command line, run vcvars32.bat for Visual C++ 6.0.) The system is Windows NT 4.0 SP6. I'm using a fresh cvs checkout of the entire boost source tree. I'd appreciate any help I can get with this. Thx, Bart

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[assignment library post review]
by Thorsten Ottosen 08 Jun '04

08 Jun '04

Dear All, The post review version can be downloaded from http://tinyurl.com/38c7d Since the review this has changed: 1. insert()/assign() functions has been renamed to reflect which function that is called. So now push_back() is used for vector etc. 2. One header for each standard container. 3. New functions to allow for direct initialization: vector<int> v = list_of(1)(2)(3)(4)(5); map<string,int> m = map_list_of( "Foo", 1 )( "Bar", 2 ); 4. New heavily improved documentation 5. Support for arbitrary functions s.t. new types can benefit from the syntax easily. 6. removal of all half-backed stuff that nobody wanted 7. arguments are forwarded by value instead of const-reference. Reference is a pain to deal with when it comes to string literals. 8. A real test-suite has been added 9. portability has suffered a bit, but that can be solved later. Any comments about docs/implementation are welcome. There is one major isssue we must resolve: What should we call this library. Here are some choices: 1. Initialization library 2. Assignment library 3. Populate library 4. List library I personally would like Boost.List because the library is all about making list for use in various context. best regards Thorsten

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[prereview request][fsm]
by Andreas Huber 07 Jun '04

07 Jun '04

Dear Boosters I think boost::fsm has finally reached a state that is worthy of a formal review. The .zip can be found here: http://boost-sandbox.sf.net/fsm.zip The docs are also available online: http://boost-sandbox.sf.net/libs/fsm As always: Feedback is highly welcome. Regards, Andreas

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[spirit] rule<> and copying
by Thorsten Ottosen 07 Jun '04

07 Jun '04

Hi, I've been using spirit for some config-file parsing. I have some questions: 1. why can we not copy a rule<> ? 2. if we shouldn't copy a rule, why is copying not disabled? It has been a source of errors in my code that I forgot & on my return value. br Thorsten

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