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[asio] Brief Review
by Jeff Garland 10 Dec '05

10 Dec '05

This was sent to me by a boost user and I was asked to post here. Jeff ------- I'm not subscribed to the boost developer list, therefore this mail goes directly to you. How did I review: browsed through the documentation. The most obviously missing thing is the ready-made support for LOCAL (also called UNIX domain) sockets, or named pipes on Win32. These are very useful and popular IPC mechanisms. I don't know whether Win32 supports LOCAL domain sockets, and using Win32 style named pipes won't be portable (as UNIX named pipes are not bidirectional). This is not a request for implementation, but it would be nice if the author commented whether it is possible to support the following local IPC mechanisms within the library (with possible loss of functionality): 1. anonymous UNIX pipes (pipe(2) system call) 2. anonymous UNIX sockets (socketpair(2)) 3. named UNIX pipes (created by e.g. mkfifo command) and WIn32 pipes 4. LOCAL sockets I cannot give any recommendation since I didn't do a proper review. Overall, judging from the examples and the reference documentation, the library seems simple to use and extensible. Another plus is the header-only implementation.

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Re: [boost] intrusive_ptr and overloading not working under VC++ 8
by art 10 Dec '05

10 Dec '05

Does intrusive_ptr work with overloading on any other compiler? This is a general problem and as I proposed above to solve the ambiguity you have to use SFINE in template constructor of intrusive_ptr/shared pointer. template< class T2 > shared_ptr( const shared_ptr<T2>& s_ptr, typename enable_if<is_convertible<T*,T2*>::result, void* >::type = 0) { ... } I think it should be added to boost smartptr. Artyom "Stefan Popov" <stefan.popov(a)gmail.com> wrote in message news:<6dbc126a0512091009y28a7c321if705f64ef22999f0(a)mail.gmail.com>... > I ran onto a problem when using intrusive_ptr, overloading and MS > visual studio 8 > > All my classes derive a reference counted class RefCnt. For example: > > class GLTexture : public RefCnt {...}; > class GLRenderBuffer : public RefCnt {...}; > > I define smart pointers using the intrusive_ptr class: > > typedef boost::intrusive_ptr<GLTexture> GLTexturePtr; > typedef boost::intrusive_ptr<GLRenderBuffer> GLRenderBufferPtr; > > Than I define a function accepting both GLTexturePtr and GLRenderBufferPtr : > > void attachTarget(GLTexturePtr aTexture); > void attachTarget(GLRenderBufferPtr aBuffer); > > invoking <code>attach(new GLTexture)</code> leads to an error: > ambiguous function call. > > The reason is in the contructor of intrusive_ptr: > template<class U> intrusive_ptr(intrusive_ptr<U> const & rhs) ... > which allows an invocation with an unrelated pointer. > > Changing the constructor to > template<class U> intrusive_ptr( > intrusive_ptr<U> const & rhs, > typename enable_if<boost::is_convertible<typename > boost::add_const<U*>::type, typename boost::add_const<T*>::type > > >::type* dummy = NULL > ) > > resolves the problem. > > I think this is a bug. > > Best, > Stefan > > _______________________________________________ > Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost >

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[boost/bind.hpp]
by Robert Ramey 10 Dec '05

10 Dec '05

I've moved changes from RC_1_33_0 to HEAD and tested on my own machine. I've got a couple of problems. The first one shows up and compilation error with both versions of Borland (5.51 and 5.64). C:\BoostHead\libs\serialization\build\../src/xml_grammar.cpp: Error E2272 C:\BoostHead\boost/bind.hpp 1579: Identifier expected Error E2188 C:\BoostHead\boost/bind.hpp 1579: Expression syntax Error E2299 C:\BoostHead\boost/bind.hpp 1582: Cannot generate template specialization from 'add_cref<Pm,I>' Error E2428 C:\BoostHead\boost/bind.hpp 1589: Templates must be classes or functions Error E2401 C:\BoostHead\boost/bind.hpp 1616: Invalid template argument listI believe this is due to changes made in boost/bind.hpp by Peter Dimov in the head after the RC_1_33_0 was branched. Peter, could you take a look at this? Robert Ramey

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intrusive_ptr and overloading not working under VC++ 8
by Stefan Popov 10 Dec '05

10 Dec '05

I ran onto a problem when using intrusive_ptr, overloading and MS visual studio 8 All my classes derive a reference counted class RefCnt. For example: class GLTexture : public RefCnt {...}; class GLRenderBuffer : public RefCnt {...}; I define smart pointers using the intrusive_ptr class: typedef boost::intrusive_ptr<GLTexture> GLTexturePtr; typedef boost::intrusive_ptr<GLRenderBuffer> GLRenderBufferPtr; Than I define a function accepting both GLTexturePtr and GLRenderBufferPtr : void attachTarget(GLTexturePtr aTexture); void attachTarget(GLRenderBufferPtr aBuffer); invoking <code>attach(new GLTexture)</code> leads to an error: ambiguous function call. The reason is in the contructor of intrusive_ptr: template<class U> intrusive_ptr(intrusive_ptr<U> const & rhs) ... which allows an invocation with an unrelated pointer. Changing the constructor to template<class U> intrusive_ptr( intrusive_ptr<U> const & rhs, typename enable_if<boost::is_convertible<typename boost::add_const<U*>::type, typename boost::add_const<T*>::type > >::type* dummy = NULL ) resolves the problem. I think this is a bug. Best, Stefan

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Boost regression notification (2005-12-10 [HEAD])
by Douglas Gregor 10 Dec '05

10 Dec '05

Boost regression test failures ------------------------------ Report time: 2005-12-10T15:25:19Z This report lists all regression test failures on release platforms. Detailed report: http://engineering.meta-comm.com/boost-regression/CVS-HEAD/developer/issues… 347 failures in 18 libraries: assign (1) bind (1) concept_check (17) date_time (20) foreach (1) graph (11) io (1) mpl (1) multi_array (1) parameter (1) python (1) serialization (40) smart_ptr (2) spirit (2) tr1 (177) typeof (23) wave (2) xpressive (45) |assign| list_inserter: vc-7_1 |bind| bind_dm3_test: msvc |concept_check| stl_concept_covering: cw-9_4 cw-9_4 cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin intel-win32-8_1 intel-win32-9_0 intel-win32-9_0 intel-win32-9_0 mingw-3_4_2 msvc vc-7_1 vc-7_1 vc-7_1 |date_time| testc_local_adjustor: msvc testclock: msvc testdst_rules: msvc testfiletime_functions: msvc testgreg_duration_operators: msvc testgreg_serialize_dll: cw-9_4 intel-win32-8_1 intel-win32-9_0 vc-7_1 vc-7_1 vc-7_1 testiterator: msvc testlocal_adjustor: msvc testmicrosec_time_clock: msvc testparse_time: msvc testtime: msvc testtime_formatters: msvc testtime_period: msvc testwcustom_time_zone: msvc testwposix_time_zone: msvc |foreach| rvalue_const: intel-win32-9_0 |graph| csr_graph_test: cw-9_4 cw-9_5-darwin dominator_tree_test: cw-9_4 cw-9_5-darwin intel-win32-9_0 vc-7_1 vc-7_1 graphviz_test: vc-7_1 vc-7_1 vc-7_1 layout_test: intel-win32-9_0 |io| ios_state_unit_test: intel-win32-9_0 |mpl| size_t: gcc-4_0-darwin |multi_array| index_bases: cw-9_4 |parameter| sfinae: msvc |python| stl_iterator: msvc |serialization| test_class_info_load_binary_archive: cw-9_5-darwin gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_binary_archive_dll: cw-9_5-darwin gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_text_archive: gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_text_archive_dll: gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_text_warchive: gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_text_warchive_dll: gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_xml_archive: cw-9_5-darwin gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_xml_archive_dll: cw-9_5-darwin gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_xml_warchive: gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_class_info_load_xml_warchive_dll: gcc-3_3-darwin gcc-3_4_3-sunos gcc-4_0-darwin test_const_save_fail1: msvc test_const_save_fail2: msvc test_const_save_fail3: msvc test_map_binary_archive_dll: msvc test_map_text_archive_dll: msvc test_map_text_warchive_dll: msvc |smart_ptr| pointer_to_other_test: msvc shared_ptr_alloc2_test: msvc |spirit| traverse_tests: intel-win32-9_0 traverse_tests_debug: intel-win32-9_0 |tr1| run_complex_overloads: cw-9_4 cw-9_5-darwin gcc-3_4_3-sunos std_run_complex_overloads: cw-9_4 cw-9_5-darwin gcc-3_4_3-sunos std_run_random: cw-9_4 cw-9_5-darwin std_test_array: cw-9_4 cw-9_5-darwin std_test_bind: cw-9_4 cw-9_5-darwin std_test_complex: cw-9_4 cw-9_5-darwin std_test_function: cw-9_4 cw-9_5-darwin std_test_hash: cw-9_4 cw-9_5-darwin std_test_mem_fn: cw-9_4 cw-9_5-darwin std_test_random: cw-9_4 cw-9_5-darwin std_test_regex: cw-9_4 cw-9_5-darwin std_test_result_of: cw-9_4 cw-9_5-darwin std_test_tr1_include: cw-9_4 cw-9_5-darwin std_test_tuple: cw-9_4 cw-9_5-darwin std_test_type_traits: cw-9_4 cw-9_5-darwin test_array: cw-9_4 test_bind: cw-9_4 cw-9_5-darwin test_complex: cw-9_4 cw-9_5-darwin test_function: cw-9_4 cw-9_5-darwin test_hash: cw-9_4 cw-9_5-darwin test_mem_fn: cw-9_4 cw-9_5-darwin test_random: cw-9_4 cw-9_5-darwin test_reference_wrapper: cw-9_4 cw-9_5-darwin test_result_of: cw-9_4 cw-9_5-darwin test_shared_ptr: cw-9_4 cw-9_5-darwin test_tr1_include: cw-9_4 cw-9_5-darwin test_tuple: cw-9_4 cw-9_5-darwin tr1_add_const_test: cw-9_4 cw-9_5-darwin tr1_add_cv_test: cw-9_4 cw-9_5-darwin tr1_add_pointer_test: cw-9_4 cw-9_5-darwin tr1_add_reference_test: cw-9_4 cw-9_5-darwin tr1_add_volatile_test: cw-9_4 cw-9_5-darwin tr1_aligned_storage_test: cw-9_4 cw-9_5-darwin tr1_alignment_of_test: cw-9_4 cw-9_5-darwin tr1_extent_test: cw-9_4 cw-9_5-darwin tr1_has_nothrow_assign_test: cw-9_4 cw-9_5-darwin tr1_has_nothrow_constr_test: cw-9_4 cw-9_5-darwin tr1_has_nothrow_copy_test: cw-9_4 cw-9_5-darwin tr1_has_tr1_ref_wrap_fail: cw-9_4 cw-9_5-darwin tr1_has_tr1_shared_ptr_fail: cw-9_4 cw-9_5-darwin tr1_has_tr1_tuple_fail: cw-9_4 cw-9_5-darwin tr1_has_trivial_assign_test: cw-9_4 cw-9_5-darwin tr1_has_trivial_constr_test: cw-9_4 cw-9_5-darwin tr1_has_trivial_copy_test: cw-9_4 cw-9_5-darwin tr1_has_trivial_destructor_test: cw-9_4 cw-9_5-darwin tr1_has_virtual_destructor_test: cw-9_4 cw-9_5-darwin tr1_is_arithmetic_test: cw-9_4 cw-9_5-darwin tr1_is_array_test: cw-9_4 cw-9_5-darwin tr1_is_base_of_test: cw-9_4 cw-9_5-darwin tr1_is_class_test: cw-9_4 cw-9_5-darwin tr1_is_compound_test: cw-9_4 cw-9_5-darwin tr1_is_const_test: cw-9_4 cw-9_5-darwin tr1_is_convertible_test: cw-9_4 cw-9_5-darwin tr1_is_empty_test: cw-9_4 cw-9_5-darwin tr1_is_enum_test: cw-9_4 cw-9_5-darwin tr1_is_floating_point_test: cw-9_4 cw-9_5-darwin tr1_is_function_test: cw-9_4 cw-9_5-darwin tr1_is_fundamental_test: cw-9_4 cw-9_5-darwin tr1_is_integral_test: cw-9_4 cw-9_5-darwin tr1_is_member_func_test: cw-9_4 cw-9_5-darwin tr1_is_member_obj_test: cw-9_4 cw-9_5-darwin tr1_is_member_pointer_test: cw-9_4 cw-9_5-darwin tr1_is_object_test: cw-9_4 cw-9_5-darwin tr1_is_pod_test: cw-9_4 cw-9_5-darwin tr1_is_pointer_test: cw-9_4 cw-9_5-darwin tr1_is_polymorphic_test: cw-9_4 cw-9_5-darwin tr1_is_reference_test: cw-9_4 cw-9_5-darwin tr1_is_same_test: cw-9_4 cw-9_5-darwin tr1_is_scalar_test: cw-9_4 cw-9_5-darwin tr1_is_signed_test: cw-9_4 cw-9_5-darwin tr1_is_union_test: cw-9_4 cw-9_5-darwin tr1_is_unsigned_test: cw-9_4 cw-9_5-darwin tr1_is_void_test: cw-9_4 cw-9_5-darwin tr1_is_volatile_test: cw-9_4 cw-9_5-darwin tr1_rank_test: cw-9_4 cw-9_5-darwin tr1_remove_all_extents_test: cw-9_4 cw-9_5-darwin tr1_remove_const_test: cw-9_4 cw-9_5-darwin tr1_remove_cv_test: cw-9_4 cw-9_5-darwin tr1_remove_extent_test: cw-9_4 cw-9_5-darwin tr1_remove_pointer_test: cw-9_4 cw-9_5-darwin tr1_remove_reference_test: cw-9_4 cw-9_5-darwin tr1_remove_volatile_test: cw-9_4 cw-9_5-darwin tr1_tricky_abstract_type_test: cw-9_4 cw-9_5-darwin tr1_tricky_add_pointer_test: cw-9_4 cw-9_5-darwin tr1_tricky_function_type_test: cw-9_4 cw-9_5-darwin tr1_tricky_incomplete_type_test: cw-9_4 cw-9_5-darwin tr1_tricky_is_enum_test: cw-9_4 cw-9_5-darwin tr1_tricky_partial_spec_test: cw-9_4 cw-9_5-darwin |typeof| data_member_native: cw-9_4 function_native: cw-9_4 msvc function_ptr_native: cw-9_4 function_ref_native: cw-9_4 lvalue_native: cw-9_4 msvc member_function_native: cw-9_4 modifiers_emulation: cw-9_4 modifiers_native: cw-9_4 noncopyable_native: cw-9_4 std_emulation: cw-9_4 cw-9_4 cw-9_5-darwin std_native: cw-9_4 template_dependent_native: cw-9_4 template_enum_native: cw-9_4 template_int_native: cw-9_4 template_multiword_native: cw-9_4 template_tpl_native: cw-9_4 msvc template_type_native: cw-9_4 type_native: cw-9_4 |wave| testwave_dll: cw-9_4 cw-9_5-darwin |xpressive| misc1: cw-9_4 cw-9_5-darwin test1: cw-9_4 cw-9_5-darwin test1u: cw-9_4 cw-9_5-darwin test2: cw-9_4 cw-9_5-darwin test2u: cw-9_4 cw-9_5-darwin test3: cw-9_4 cw-9_5-darwin test3u: cw-9_4 cw-9_5-darwin test4: cw-9_4 cw-9_5-darwin test4u: cw-9_4 cw-9_5-darwin test5: cw-9_4 cw-9_5-darwin test5u: cw-9_4 cw-9_5-darwin test6: cw-9_4 cw-9_5-darwin test6u: cw-9_4 cw-9_5-darwin test7: cw-9_4 cw-9_5-darwin test7u: cw-9_4 cw-9_5-darwin test8: cw-9_4 cw-9_5-darwin test8u: cw-9_4 cw-9_5-darwin test9: cw-9_4 cw-9_5-darwin test9u: cw-9_4 cw-9_5-darwin test_cycles: cw-9_4 cw-9_5-darwin test_dynamic: cw-9_4 cw-9_5-darwin test_non_char: cw-9_4 cw-9_5-darwin test_static: cw-9_4

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[iostreams][vc8] a warning in file_descriptor.cpp
by Yuval Ronen 10 Dec '05

10 Dec '05

Hi. Compiling Boost with VC8 emits this warning: boost_1_33_1\libs\iostreams\build\..\src\file_descriptor.cpp(198) : warning C4293: '<<' : shift count negative or too big, undefined behavior I have no idea if this indicates a real bug or not. FYI. Yuval

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serialization and databases
by Chris Frey 10 Dec '05

10 Dec '05

Hi, Has anyone used boost::serialization to write simple classes to an RDBMS? The Name-Value-Pair support would seem to make this quite possible, and I'm curious if anyone has taken the plunge. Thanks, - Chris

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BOOST_ENUM proposal
by Frank Laub 10 Dec '05

10 Dec '05

Hello fellow boosters, I've recently come up with a way to use the boost preprocesor to generate a 'better' enum type. The following is an example of some typical usage. Is anyone else interested in this sort of thing? I'm hoping to get suggestions for how to make it more 'boost-like' in both its implementation and its usage. Is this very readable? Is there a place I can upload the code for people to peruse? #include <iostream> #include <boost/enum.hpp> #include <boost/foreach.hpp> #define foreach BOOST_FOREACH BOOST_ENUM(Level, (Abort)("unrecoverable problem") (Error)("recoverable problem") (Alert)("unexpected behavior") (Info)("expected behavior") (Trace)("normal flow of execution") (Debug)("detailed object state listings") ) int main() { foreach(const string& name, Level::names) { cout << name << endl; } cout << "1: " << Level::names[1] << endl; cout << "toString(Abort): " << Level::toString(Level::Abort) << endl; cout << "getValue(Abort): " << Level::getValue(Level::Abort) << endl; Level::type value = Level::Invalid; bool ret = Level::fromString("Abort", value); cout << "fromString(\"Abort\"): " << ret << ", " << value << endl; value = Level::Invalid; ret = Level::fromString("Debug", value); cout << "fromString(\"Debug\"): " << ret << ", " << value << endl; value = Level::Invalid; ret = Level::fromString("not in enum", value); cout << "fromString(\"not in enum\"): " << ret << ", " << value << endl; return 0; } With the program output being: Abort Error Alert Info Trace Debug Invalid 1: Error toString(Abort): Abort getValue(Abort): unrecoverable problem fromString("Abort"): 1, 0 fromString("Debug"): 1, 5 fromString("not in enum"): 0, 6 -Frank

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[boost::throw_exception] and platforms where it don't throw
by Thorsten Ottosen 09 Dec '05

09 Dec '05

Hi All, I'm about to replace all my throw Foo; statetements in the Pointer Container library with something else to support platforms without exceptions. Is using boost::throw_exception the way to do it? If I where on such a platform, I kinda think that I would have preferred an assertion *at the throw spot* instead of making the call stack deeper yet and then call about or something. Thanks for any feedback -Thorsten

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[Defer] Decorated callbacks suggestion
by simon meiklejohn 09 Dec '05

09 Dec '05

This post suggests apply a Decorator like pattern to the Defer/Asio::demuxer style libraries. Where previously a component requests a deferred execution of a function f() it would now be possible to get f() called at the end of a chain of wrapping functions a( b( c( d( e( f() ) ) ) ) ); the decorating functions would be of the form void func( boost::function( void (void) ) ) i.e. they can be composed into a chain using boost::bind Of itself that looks pretty trivial. Where it becomes more interesting is when you consider 1. who injects the extra functions and when. 2. what can be done inside those function objects looking at the second - why would we want to decorate the eventual callback? Here are some possibilities 1. try to obtain some resource. If its not obtainable, then return without calling the decorated function 2. wait on a lock before proceeding (i.e. similar to the defer_mutex concept) 3. Create an object on the stack that helps the decorated callback - e.g. add a logging context string ("ACME callback" so when the eventual code calls LOG( "hello" ) what gets logged is "[ACME callback]hello" Apply this repeatedly - so the defer object, the defer requester and the callback target each insert a logging prefix, so LOG("hello") becomes "[DeferPool][Acme callback][My acme observer]hello" The three components that might have interesting things to insert into the chain are: 1. the owner of f() (i.e. the component registering for a callback) when it registers the callback. Lets say it inserts d() and e(). 2. the originator of the callback (e.g. the parser component from a prevoius discussion) when it initiates the callback, or when the client callback is registered 3. the provider of the defer object (e.g. main()), when it constructs the defer object. In addition to code to be executed in the chain of every callback its desirable to insert code that be executed just once by each thread in a pool (e.g. to get the pesky CoInitializeEx() called before servicing requests). Lets call these Base Thread Decorators. It may help to illustrate if i show a pseudo stack trace at the point where a callback has finally reached the innermost callback (f() in the above example). [top of stack] f() ...client supplied decorators e() d() ... callback originator decorators c() ... per defer object decorators (provided by main) b() defer_point::service_deferrals() - the thread waits for work .... base thread decorators (provided by main) a() - e.g. call CoInitEx... .... thread entry point defer_point::thread_entry() .... [bottom of stack] ------------------------------------ So i guess the point is - defer_point could usefully provide some methods for injecting decorators to be applied to all callbacks, as well as some methods to help callback recipients and callback originators to decorate their callbacks. Does this seem a useful addition? Just more crazy talk from a thread-obsessed idiot? Cheers Simon Meiklejohn

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