November 2013 - Boost - lists.preview.boost.org

[context] msvc /SAFESEH
by Jeff Flinn 12 Aug '15

12 Aug '15

I need to build my application with /SAFESEH which uses boost coroutine which uses context. I'm getting the following link errors: 1>libboost_context-vc100-mt-gd-1_53.lib(jump_i386_ms_pe_masm.obj) : error LNK2026: module unsafe for SAFESEH image. 1>libboost_context-vc100-mt-gd-1_53.lib(make_i386_ms_pe_masm.obj) : error LNK2026: module unsafe for SAFESEH image. I've built boost static libs with the same MSVC vesion and options (sans /SAFESEH as it's not a compile/lib option) … [View More]

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Is there any interest in a library for actor programming?
by Charousset, Dominik 28 May '14

28 May '14

Hi, is there any interest in a library for actor programming? The library we've developed is a C++11 open source library named "libcppa". It is currently released under LGPL2, but re-releasing the library under the boost license is not an issue. You'll find all important links and ressources either under http://libcppa.org or on the GitHub project page: https://github.com/Neverlord/libcppa, including a user manual as HTML or PDF. We've also submitted a paper to the C++Now conference. What is … [View More]actor programming? For those of you who aren't yet familiar with the actor model: actors basically represent tasks or services that communicate via message passing. In libcppa, actors are very lightweight (you can spawn literally millions of them) and scheduled cooperatively using a thread pool (although actors are allowed to opt-out of the cooperative scheduling). Some of the main strengths of this programming paradigm are: (1) network transparency, (2) race conditions are avoided by design, (3) a strong failure model that enables developers to build reliable distributed systems, and (4) the actor model addresses both concurrency (multiple actors on one host) and distribution (any number of actors on any number of hosts). Here's the classical hello world example: ---------------------------------------------------------------------------------- #include <string> #include <iostream> #include "cppa/cppa.hpp" using namespace std; using namespace cppa; void mirror() { // wait for messages become ( // invoke this lambda expression if we receive a string on_arg_match >> [](const string& what) { // prints "Hello World!" via aout (thread-safe cout wrapper) aout << what << endl; // replies "!dlroW olleH" reply(string(what.rbegin(), what.rend())); // terminates this actor ('become' otherwise loops forever) self->quit(); } ); } void hello_world(const actor_ptr& buddy) { // send "Hello World!" to our buddy ... sync_send(buddy, "Hello World!").then( // ... and wait for a response on_arg_match >> [](const string& what) { // prints "!dlroW olleH" aout << what << endl; } ); } int main() { // create a new actor that calls 'mirror()' auto mirror_actor = spawn(mirror); // create another actor that calls 'hello_world(mirror_actor)' spawn(hello_world, mirror_actor); // wait until all other actors we have spawned are done await_all_others_done(); // run cleanup code before exiting main shutdown(); } ---------------------------------------------------------------------------------- A message is simply a tuple of values that is pattern matched at the receiver. For example, " on_arg_match >> [](const string& what) {...}" defines a message handler that is called whenever a tuple with one single string element arrives. "on_arg_match" simply defines a pattern that matches the signature of the given lambda. Please have a look at the examples folder on GitHub (https://github.com/Neverlord/libcppa/tree/master/examples) or at the user manual (http://neverlord.github.io/libcppa/manual/) if you want to see more examples. Best regards, Dominik Charousset [View Less]

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required toolsets
by Steven Watanabe 15 May '14

15 May '14

AMDG The list of required toolsets in explicit-failures-markup.xml is out-dated. Therefore, if no one objects, I propose setting it to the following: msvc-10.0, msvc-11.0, gcc-4.6, gcc-4.7, clang-darwin-11, clang-darwin-4.2.1, clang-linux-3.1, clang-linux-3.2, gcc-mingw-4.7, gcc-mingw-4.6 (two releases of each major compiler that appears in both the trunk and release regression tests) The sole effect of this is to determine which toolsets appear in the issues list: http://www.boost.org/… [View More]

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[atomic] Support for specialized instructions
by Andrey Semashev 14 May '14

14 May '14

Hi, I've been contemplating the idea of adding support for some specialized atomic instructions to Boost.Atomic. Since I'm only familiar with x86 architecture, my current candidates are: * Increment/decrement with a check for zero result (lock inc/dec). The decrement is the most essential of the two because it would be useful for reference counters of various kinds. The increment is mostly beneficial in terms of code size, and it probably doesn't need the check for zero in most cases. * In-… [View More]

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[asio] Bug: Handlers execute on the wrong strand.
by Greg Barron 04 Apr '14

04 Apr '14

Hi All, I would like to refer you to this bug report: https://svn.boost.org/trac/boost/ticket/9203 I won't paste the full contents of the bug report into this message. The executive summary is that the allocation algorithm for the implementation of asio::strand can and does allocate the implementation of an existing strand to strands that are subsequently allocated. This can have the effect that handlers wrapped in strand (b) will actually be executed on strand (a). I consider this to be a … [View More]

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Post-git forking process
by Sohail Somani 29 Mar '14

29 Mar '14

Hey all, Often, I find bugs in Boost that I need to patch manually before the next release. What I used to do before was keep a copy of Boost in my source tree which made this easier: just patch it directly. This made it easy to modify, but annoying to post patches and honestly, they just got lost most of the time. With Git, it should become easier to contribute said patches as well as pull in whichever particular changes I need. However when I attempted such a fork recently, I was a … [View More]

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sqlpp11: SQL for C++
by Roland Bock 06 Feb '14

06 Feb '14

Hi, over the last four or five years I developed several SQL libraries for C++. With C++11 I was finally able to create an SQL library that meets my own expectations and requirements. It is being used in production, I recently put it on github, and I would really like to hear from you guys whether this is something that could be interesting for you personally or for boost? https://github.com/rbock/sqlpp11 https://github.com/rbock/sqlpp11/wiki sqlpp11 is a template library representing an … [View More]embedded domain specific language (EDSL) that allows you to * define types representing tables and columns, * construct type safe queries checked at compile time for syntax errors, type errors, name errors and even some semantic errors, * interpret results by iterating over query-specific structs with appropriately named and typed members. This results in several benefits, e.g. * the library user operates comfortably on structs and functions, * the compiler reports many kinds of errors long before the code enters unit testing or production, * the library hides the gory details of string construction for queries and interpreting string based results returned by select calls. I.e. you don't need to use strings in query construction where you wouldn't use them in SQL and there is no need to use positional arguments or to parse strings when obtaining fields from a result row (the latter being true unless you do not know which columns to select at compile time). The library supports both static and dynamic queries. The former offers greater benefit in terms of type and consistency checking. The latter makes it easier to construct queries on the flight. Specific traits of databases (e.g. unsupported or non-standard features) are known at compile time as well. This way, the compiler can tell the developer at compile time if a query is not accepted by the database (e.g. if a feature is missing). And the library can form the query in the correct manner, for instance if the engine uses concat instead of operator|| to concatenate strings. Two Examples: ============= Static Select: -------------- // selecting zero or more results, iterating over the results for (const auto& row : db.run( select(foo.name, foo.hasFun) .from(foo) .where(foo.id > 17 and foo.name.like("%bar%")))) { if (row.name.is_null()) std::cerr << "name will convert to empty string" << std::endl; std::string name = row.name; // text fields are implicitly convertible to string bool hasFun = hasFun; // bool fields are implicitly convertible to bool } Dynamic Select: ---------------- auto s = dynamic_select(db, tab.foo).dynamic_columns().from(tab); if (userWantsBar) s.add_column(tab.bar); for(const auto& row : run(s)) { std::cerr << "row.foo: " << row.foo; if (userWantsBar) std::cerr << "row.bar" << row.at("bar"); std::cerr << std::endl; }; Please let me know your questions/thoughts/suggestions/rants. Contributions welcome, of course :-) Regards, Roland [View Less]

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C++03 and C++11 ABI compatibility for compiled libraries
by Andrey Semashev 24 Jan '14

24 Jan '14

Hi, I would like to raise the issue of binary compatibility of compiled Boost libraries between C++03 and C++11. I faced this problem with gcc on Linux, but other compilers and platforms may be affected as well. To summarize the problem: * Most, if not all Linux distributions build packages in C++03 mode. This is also the default in gcc. * Some Boost libraries conditionally use C++11 features in their binary interfaces (see [1] as an example). This makes C++03 and C++11 versions of the … [View More]

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Re: [boost] Is there interest in a collection of call stack utilities?
by Aurelian Melinte 14 Jan '14

14 Jan '14

Hello, To follow up on the discussion https://groups.google.com/forum/#!topic/boost-developers-archive/PSwTBEEe0Ao I was not clear if there is interest for it or not. I went ahead and the first cut of the code is now at https://github.com/melintea/Boost-Call_stack Please feel free to take a look and comment. Regards, Aurelian

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Removing support for old compilers
by Joaquin M Lopez Munoz 14 Jan '14

14 Jan '14

Hi Stephen As part of your initiative of removing support for old compilers, are you building somewhere a change log in the form of either a list of compiler deficiencies or compiler versions no longer supported? I understand this should be inserted in a prominent place on the Boost 1.56 release notes and can serve as a reference for lib maintainers reviewing your patches (tracking changesets is harder and commit messages are not always completely illuminating). Thank you, Joaquín M López Muñoz Telefónica Digital

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[block_ptr] & Java
by Phil Bouchard 14 Jan '14

14 Jan '14

Hello everyone, In a quest to speed up my Android applications and knowing Java is written in C++, I decided to discuss with the OS community openjdk.java.net to try to introduce them block_ptr. But the conversation was dead in the water probably due to the lack of developers. So I just have questions: - Does anybody know if Java uses Boost? - block_ptr hasn't been reviewed yet but memory management is an important subject. Are there unanswered questions about it? Sincerely, -Phil … [View More]

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[Macro]Test Case grouping using Traits
by Hemanth Choudary M V (RBEI/ETA1) 13 Jan '14

13 Jan '14

Hello, I have observed that in native unit test framework(c++), there is an option to group test cases using attributes which are reflected as traits in the Test Explorer window in MS VS2012. Following is a an example of the same: BEGIN_TEST_METHOD_ATTRIBUTE(TestMethod3) TEST_OWNER(L"SuperMan") TEST_PRIORITY(2) TEST_METHOD_ATTRIBUTE(L"Category",L"Slow") END_TEST_METHOD_ATTRIBUTE() TEST_METHOD(TestMethod3) { Assert::AreEqual(2,6); } How can this be achieved via Boost Unit Test … [View More]

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[Test] Problems with debug::break_memory_alloc
by Fredrik Orderud 13 Jan '14

13 Jan '14

I have a problem with the memory-leak detection logic in boost.test. What happens when unit_test::framework::init starts up on Windows is that memory-leak detection is first explicitly activated. Secondly, debug::break_memory_alloc is called with a value (default is 1). Activation of leak detection is great, but to always override the allocation number to break on is not necessary a good idea if the user has already set a value from a debugger. In my case I am investigating a leak from a … [View More]

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[test] broken (fails to compile) with boost.timer since 1.48
by Jamie Allsop 13 Jan '14

13 Jan '14

Boost.Test fails to compile since 1.48 when Boost.Timer is included. I find that often I want to use timers when testing. I reported this back in 2012 along with a comprehensive patch that fixes the issue. On the eve of 1.55 I see the patch has still not been applied, despite an original agreement to do so. Unfortunately I don't have commit privileges so I am unable to do this myself. The original discussion from here: http://lists.boost.org/Archives/boost/2012/09/196811.php went as … [View More]follows: > On 25/09/12 18:14, Gennadiy Rozental wrote: >> Jamie Allsop<ja11sop<at> yahoo.co.uk> writes: >> >>> >>> These are patches we've been using for some time locally, the recent >>> discussions highlighted the importance of pushing patches like these to >>> a wider audience. >>> >>> In summary the key changes are: >>> >>> * https://svn.boost.org/trac/boost/ticket/7410 >>> * https://svn.boost.org/trac/boost/ticket/7397 >> >> These are fine. I'll try to check it in on a weekend > > Excellent thanks! Yet https://svn.boost.org/trac/boost/ticket/7397 was never applied. With changes to Boost.Test since then it is likely that the patch needs modified to be applied but that should not be too hard. Apart from that I'd like to see the suite of 4 patches applied as a whole. So far only https://svn.boost.org/trac/boost/ticket/7410 has been applied but the patches address severe use-case short-comings in Boost.Test that make it viable for broader testing use. I've summaried them below. * https://svn.boost.org/trac/boost/ticket/7397 * https://svn.boost.org/trac/boost/ticket/7410 (applied) * https://svn.boost.org/trac/boost/ticket/7417 (small) * https://svn.boost.org/trac/boost/ticket/7419 (small) Original discussion that didn't really get very far was in these threads: * http://lists.boost.org/Archives/boost/2012/09/196811.php * http://lists.boost.org/Archives/boost/2012/09/196828.php For those who are interested I've pasted my original motivations from the year old thread below as a reminder. Basically the patches allow Boost.Test to: * compile with Boost.Timer (so not broken) * output test progress on the fly in a format other tools could parse * allows Boost.Test to be used for live test diagnostics in running systems in a 'test' mode Jamie * https://svn.boost.org/trac/boost/ticket/7410 (applied) * all test cases/suites have file and line information captured so that external tools can use the Boost.Log output to create links into the source tree, answering questions like, "What is this test case?". It is possible to simply follow the link and see. * https://svn.boost.org/trac/boost/ticket/7417 * update the Boost.Test log output to include summary status information when a test case or suite is completed. This includes the test status, assertions passed and total assertions. This allows live test status to be viewed and nicer tools to be built around this. For example each test can be shown starting, in progress and then complete with the resulting status in detail. I should note that Boost.Test reports currently output this additional test status but this is done only on *completion of all tests* and so *cannot* be used to show live progress. * this additional test status as part of the log can be easily captured using regular expressions if HRF is used and many IDEs will allow colourisation, autolinking and so on using similar approaches. * https://svn.boost.org/trac/boost/ticket/7397 * update Boost.Test to use the new Boost.Timer classes introduced in Boost 1.48. This can be suppressed through the use of a macro should the old timers be preferred. The new Boost.Timer provides much better timing information than the old Boost.Timer library. You should refer to the library itself for an explanation of why the previous timer library was deprecated: http://www.boost.org/doc/libs/1_51_0/libs/timer/doc/index.html * https://svn.boost.org/trac/boost/ticket/7419 Essentially the patch does two things: * It allows boost::unit_test_framework::init() to be called more than once. The result is to reset the test status and master test suite so that new tests can be added and new reports generated through multiple calls. The CLA parsing is also reset. Recent changes to this code may make my call to clear() redundant. I'll let Gennadiy be the judge of that. * This first change then allows the framework setup and teardown to be encapsulated in a helper class (not provided in the patch but one could be). In our systems we use a helper class that exposes a simple API that allows the user to implement a method where test units can be added directly to the master test suite - see the ticket for an example. As I said the patch focuses solely on enabling the possibility of writing such a class, not the class itself. * It provides scoped Boost.Test arguments for the commandline when BOOST_TEST_USE_QUALIFIED_COMMANDLINE_ARGUMENTS is defined. All command line arguments are then called --boost.test.<argument> for example --boost.test.log_level instead of --log_level. This of course means that all Boost.Test related arguments will not clash with any program arguments. On its own this is a generally useful feature as it allows custom main() functions to pass arguments down to other components during simple unit testing. [View Less]

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[test] still broken in release
by Tim Blechmann 30 Dec '13

30 Dec '13

hi all, i've reported an issue before that boost.test in the release branch is pretty broken. *all* tests of the boost.heap testsuite segfault like this: --Program received signal SIGSEGV, Segmentation fault. 0x00000000005f4975 in boost::unit_test::test_suite::add (this=0x8cefa0, tu=0x9, expected_failures=0, timeout=0) at ../../../boost/test/impl/unit_test_suite.ipp:139 139 m_members.push_back( tu->p_id ); (gdb) bt #0 0x00000000005f4975 in boost::unit_test::test_suite::add (this=… [View More]

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[test] Interest in 'hamcrest'-style checks?
by Jared Grubb 29 Dec '13

29 Dec '13

I recently read "Modern C++ Programming with Test-Driven Development", and I really enjoyed this book and highly recommend it. One of the styles I saw for the first time was "hamcrest"-style assertions. ("Hamcrest" is an anagram of "matchers"; also see http://en.wikipedia.org/wiki/Hamcrest.) For a quick idea, imagine there is a BOOST_CHECK_THAT macro that looks like this: (excuse my choice of names here, we can pick better ones if people like the idea) BOOST_CHECK_THAT( str, IsEqualTo(expStr) … [View More]); BOOST_CHECK_THAT( str, HasSubstring(needleStr) ); BOOST_CHECK_THAT( str, Not(HasSubstring(badStr)) ); BOOST_CHECK_THAT( vec, Contains(42) ); Comparing them to current boost::test assertions, usually the two are directly equivalent, and it's just a matter of style. At first, I was unconvinced of a need for this. However, there are a few scenarios where the hamcrest-style actually are really helpful: BOOST_CHECK_THAT(vec, Any(Contains(42), Contains(-42)) ); BOOST_CHECK_THAT(str, All(StartsWith("abc"), HasSubstring("lmnop"), EndsWith("xyz")) ); BOOST_CHECK_THAT(count, All(GE(0), LT(10)) ); BOOST_CHECK_THAT(vec, HasSubsequence(otherVec) ); BOOST_CHECK_THAT(vec, Sorted(IsEqualTo({1, 2, 3})) ); BOOST_CHECK_THAT(optionalStr, Any(IsEqualTo(boost::none), Deref(IsEqualTo("str"))); Sure, almost all of this is already doable: BOOST_CHECK_EQUAL_COLLECTIONS( /* sorry, but I really dislike this one :) */ ); BOOST_CHECK( std::count(vec.begin(), vec.end(), 42) && std::count(vec.begin(), vec.end(), -42) ); And, yes, you can create a helper functors today: BOOST_CHECK( Contains(vec, 42) && Contains(vec, -42) ); But hamcrest still gives these advantages over even that: * Dont repeat yourself: -- the value under test appears only once in the check expression; this is really helpful if you want to test an expression ("future.get()") that can only be called once * Better diagnostics: -- when something fails, you can get a detailed error (eg: "blah does not contain the element blah" or "str does not start with blah") -- when you have "Any" conditions, "errors" get squashed if some other condition passes, but all are shown if none pass -- composed tests can provide nested diagnostics; eg: for All(A, Any(B,C)), you'd get something like "'...A...' is true, but none of { '...B...' , '...C...' } are true", but spread over many lines -- and even with indentation if we want * Intentional Asymmetry: Is it BOOST_CHECK_EQ(expected, actual) or (actual, expected)? It really doesnt matter in the end, but a message like "expected 34, got 33" is actually kinda nice. Putting the value under test at the start creates an asymmetry that helps guide the user to put the values in the "right" order. * Composability * Extendibility: once the facility is there, its actually really easy to write more ("CanLockMySemaphoreType(timeout)") I wasnt able to find any discussion on boost's list for this, so I thought I'd bring it up. As for difficulty, implementing the examples above is actually already quite easy using boost::test predicates, and the extra macro would be fairly simple to implement. Almost all the work would be in creating the library of matchers, which is the fun part :) What do you think? Jared [View Less]

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[boost.test] Correct usage?
by Philip Bennefall 29 Dec '13

29 Dec '13

Hello, I just started writing unit tests for a large project that I am involved in, and boost.test has been absolutely fantastic to work with so far. True the documentation could be clearer, but as far as functionality I am very much impressed with the library. I have a question though. I read the following: http://lists.boost.org/Archives/boost/2011/10/186439.php This concerns me. What is the status here? When I build boost_1_54_0, in my stage/lib directory I see: … [View More]

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[Container] Priority Deque - Refinement
by Nathaniel McClatchey 19 Dec '13

19 Dec '13

Hi. I've recently made a double-ended priority queue (priority deque) publicly available at https://github.com/nmcclatchey/Priority-Deque , with the intent of submitting it to Boost (more specifically, I wish to make it part of Boost.Container). I would appreciate any comments, discussion, or refinements. Goals of the project: * Provide an efficient double-ended priority queue, with interface similar to std::priority_queue. * Keep requirements to a minimum. In particular, require nothing … [View More]

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[filesystem] fix recur_dir_itr_imp::increment(system::error_code* ec) in 1.54.0
by claudio.bley＠gmail.com 19 Dec '13

19 Dec '13

Hi. What's happening to the filesystem library? It seems there's no progress on any tickets in the bug tracker? Referring to https://svn.boost.org/trac/boost/ticket/6821#comment:5 Could we get this fix into 1.54.0, please? BTW, sorry for any confusion - I "managed" to comment on the wrong ticket... https://svn.boost.org/trac/boost/ticket/5403 would've been more appropriate, I guess. Claudio -- Claudio

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RFC: edit_distance / edit_alignment library
by Erik Erlandson 18 Dec '13

18 Dec '13

Boost Community, I cooked up a library that provides a pair of functions: edit_distance() and edit_alignment(). The library currently lives here: https://github.com/erikerlandson/edit_distance Some short example programs are here: https://github.com/erikerlandson/edit_distance/tree/master/examples A few example expressions: // the edit distance (aka levenshtein distance) unsigned dist = edit_distance("abc", "bcd"); // using a custom cost function for insertion, deletion, substitution … [View More]

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Any interest in a framework for memoization?
by Giacomo Drago 14 Dec '13

14 Dec '13

Hi, I would like to submit a small framework for memoization I am working on (http://projects.giacomodrago.com/c++memo/) At the moment, it is still in a beta stage and does not comply with Boost guidelines. I would like to know if you might be interested. The idea is to have a tool for rapid prototyping of software components implementing dynamic programming algorithms or, anyhow, requiring memoization. I paste here a simple "fibonacci" example: ---------------------- int fibonacci(… [View More]

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[build] Default compiler options for a toolset
by Edward Diener 10 Dec '13

10 Dec '13

How are the default compiler options for a toolset chosen ? Is it in the .jam file for the compiler toolset and, if so, where is it specified ?

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BOOST_NO_CXX11_ATOMIC?
by Peter Dimov 04 Dec '13

04 Dec '13

Now is perhaps not a very appropriate time to ask, but why don't we seem to have a macro for the <atomic> C++11 header?

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[IdentityType] Const omission undocumented.
by Mostafa 03 Dec '13

03 Dec '13

#include <boost/utility/identity_type.hpp> #include <utility> int main() { BOOST_IDENTITY_TYPE(( std::pair<int,int> const )) x; // This compiles, so the const qualification in the // above macro parameter is ignored. x = std::make_pair(0,1); return 0; } The omission of const qualification in BOOST_IDENTITY_TYPE types is undocumented. This omission maybe deduced from the documented implementation, but, as noted, that is not part of the library api and is … [View More]

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Subversion repository closed for all commits on all branches
by Beman Dawes 02 Dec '13

02 Dec '13

The Subversion repository is now closed for all commits on all branches. An attempt to commit will fail a pre-commit hook, resulting in the following error message: Command: Commit Modified: C:\boost\trunk\libs\system\doc\index.html Sending content: C:\boost\trunk\libs\system\doc\index.html Error: Commit failed (details follow): Error: Commit blocked by pre-commit hook (exit code 1) with output: Error: This Subversion repository is no longer in active use. Error: Error: It has been superseded … [View More]

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