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Re: [boost] Interest in a binary_int template for binary literals?
by Scott Schurr 15 Jul '05

15 Jul '05

Greetings, I wrote in part: > Prompted by some discussion on comp.sdt.c++.moderated, I have a > small template that allows the user to declare an integer literal > in binary. > > Usage looks like: > > #include "binary_int.hpp" > > unsigned int binary = binary_int<1001,0011,1011,0000>::b; Thanks for all the responses. Here are answers to some of the questions I got. ------------------------ Pavel Vozenilek asked: > * How does it deal with bit values like 0111? This is octal value. Right. There are specilizations for decimal and octal values. This means there is some aliasing. A few non-binary decimal and octal values leak through. For example 0111 (octal) is 73 decimal and, for that matter, 0x49 hex. So the template accepts all of these values. It's not perfect, but it's the best I could figure out. > * Does it check that the digits are 0 or 1 during compile time? It doesn't check individual digits. It checks for specific numeric values which would be good at representing a 4-bit binary value. See the binary_nibble specializations in the appended code. > * Would it work with hex values like: > bits<unsigned, 0xF,0x8>::value; No, not as it is currently implemented. ------------------------ Vladimir Prus responded: > Why is that better than > > unsigned x = strtoul("1010010001000010000001", 0, 2); > > ? I believe that 'strtoul' is part of C99. Not a bad approach. The binary_int template does the translation at compile time rather than at run time. It does the check (as best it can) for valid binary values at compile time as well. ----------------------- Paul A Bristow replied: > Can you post reference to discussion... I'm not very clever with URLs but the discussion, according to Google Groups, was titled "Power of 2 Enumerations" in comp.std.c++. The discussion in question started with a post by David Abrahams on November 1st, 2004 where he wrote: > You can even write a simple template that makes these into > compile-time constants: > > const feature_t FEATURE1 = binary<001>::value; > const feature_t FEATURE2 = binary<010>::value; > const feature_t FEATURE3 = binary<100>::value; Paul also asked: > and perhaps append the binary_int.hpp file as it sounds quite > short? Yes, the template is only 150 lines or so including comments. I've appended it, in its current state, to the end of this response. I did some editing of the template in an attempt to make it boost compatible, although I didn't put it in the Boost name space. Even though it says it's a boost file, I'm fully aware that it isn't. Sorry about that. Thanks for everyone's attention. Scott Schurr binary_int.hpp -------------------------------------------------------------- // Boost general library binary_int.hpp header file -------------------------// // Copyright Credence Systems 2005, as submitted by Scott Schurr. Use, // modification, and distribution are subject to the Boost Software License, // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #ifndef BOOST_BINARY_INT_HPP #define BOOST_BINARY_INT_HPP // Make a couple of templates to help catch bad binary_nibble parameters template <bool> struct binary_nibble_VALID_VALUES_BINARY_0000_THROUGH_1111; template <> struct binary_nibble_VALID_VALUES_BINARY_0000_THROUGH_1111<true> { }; // Write a 4-bit integer value as binary. // // Usage: // unsigned int n = binary_nibble<1011>::b // // The tricky part is remembering to include the '::b' at the end. // For example: // // #include "binary_int.h" // ... // int regValue = binary_nibble<1001>::b; // // Make a general binary_nibble type that causes a failure. Only // the specializations are valid usages. template <unsigned int v> struct binary_nibble { binary_nibble_VALID_VALUES_BINARY_0000_THROUGH_1111<false> t; enum { b = 0 }; }; // Specialize the binary_nibble template for values we allow. // The following values work for both decimal and octal. template<> struct binary_nibble<0> { enum { b = 0x0 }; }; template<> struct binary_nibble<1> { enum { b = 0x1 }; }; // Decimal values. template<> struct binary_nibble<10> { enum { b = 0x2 }; }; template<> struct binary_nibble<11> { enum { b = 0x3 }; }; template<> struct binary_nibble<100> { enum { b = 0x4 }; }; template<> struct binary_nibble<101> { enum { b = 0x5 }; }; template<> struct binary_nibble<110> { enum { b = 0x6 }; }; template<> struct binary_nibble<111> { enum { b = 0x7 }; }; template<> struct binary_nibble<1000> { enum { b = 0x8 }; }; template<> struct binary_nibble<1001> { enum { b = 0x9 }; }; template<> struct binary_nibble<1010> { enum { b = 0xA }; }; template<> struct binary_nibble<1011> { enum { b = 0xB }; }; template<> struct binary_nibble<1100> { enum { b = 0xC }; }; template<> struct binary_nibble<1101> { enum { b = 0xD }; }; template<> struct binary_nibble<1110> { enum { b = 0xE }; }; template<> struct binary_nibble<1111> { enum { b = 0xF }; }; // Octal values. template<> struct binary_nibble<010> { enum { b = 0x2 }; }; template<> struct binary_nibble<011> { enum { b = 0x3 }; }; template<> struct binary_nibble<0100> { enum { b = 0x4 }; }; template<> struct binary_nibble<0101> { enum { b = 0x5 }; }; template<> struct binary_nibble<0110> { enum { b = 0x6 }; }; template<> struct binary_nibble<0111> { enum { b = 0x7 }; }; // The following helper template determines the behavior of the // binary_int template when default arguments are passed in. // A default argument (0ul-1) will leave the previously calculated // value unchanged. A non-default argument multiplies the previously // calculated value by 16 and adds in the new (non-default) argument. template<unsigned int v> struct binary_int_arg { enum { b = binary_nibble<v>::b, mul = 16, }; }; template<> struct binary_int_arg<0ul-1> { enum { b = 0, mul = 1, }; }; // Declare a binary value in the following form: // // int i = binary_int<1100,1010,0001>::b // // Usage: // // unsigned int = binary_int<up to 16 binary_nibble>::b // // Write an integer as a binary value composed of up to 16 nibbles. // The tricky part is remembering to include the '::b' at the end. // For example: // // #include "binary_int.h" // ... // int regValue = binary_int<1000,1001,0011,0000>::b; // // One to 16 nibble-sized arguments are allowed, which allows for word // lengths up to 64 bits. If it's not working for you make sure that // you are including the closing '::b'. template<unsigned int b15, unsigned int b14 = 0ul-1, unsigned int b13 = 0ul-1, unsigned int b12 = 0ul-1, unsigned int b11 = 0ul-1, unsigned int b10 = 0ul-1, unsigned int b9 = 0ul-1, unsigned int b8 = 0ul-1, unsigned int b7 = 0ul-1, unsigned int b6 = 0ul-1, unsigned int b5 = 0ul-1, unsigned int b4 = 0ul-1, unsigned int b3 = 0ul-1, unsigned int b2 = 0ul-1, unsigned int b1 = 0ul-1, unsigned int b0 = 0ul-1> struct binary_int { private: enum { v15_ = binary_int_arg<b15>::b, v14_ = (v15_ * binary_int_arg<b14>::mul) + binary_int_arg<b14>::b, v13_ = (v14_ * binary_int_arg<b13>::mul) + binary_int_arg<b13>::b, v12_ = (v13_ * binary_int_arg<b12>::mul) + binary_int_arg<b12>::b, v11_ = (v12_ * binary_int_arg<b11>::mul) + binary_int_arg<b11>::b, v10_ = (v11_ * binary_int_arg<b10>::mul) + binary_int_arg<b10>::b, v9_ = (v10_ * binary_int_arg<b9>::mul) + binary_int_arg<b9>::b, v8_ = (v9_ * binary_int_arg<b8>::mul) + binary_int_arg<b8>::b, v7_ = (v8_ * binary_int_arg<b7>::mul) + binary_int_arg<b7>::b, v6_ = (v7_ * binary_int_arg<b6>::mul) + binary_int_arg<b6>::b, v5_ = (v6_ * binary_int_arg<b5>::mul) + binary_int_arg<b5>::b, v4_ = (v5_ * binary_int_arg<b4>::mul) + binary_int_arg<b4>::b, v3_ = (v4_ * binary_int_arg<b3>::mul) + binary_int_arg<b3>::b, v2_ = (v3_ * binary_int_arg<b2>::mul) + binary_int_arg<b2>::b, v1_ = (v2_ * binary_int_arg<b1>::mul) + binary_int_arg<b1>::b, v0_ = (v1_ * binary_int_arg<b0>::mul) + binary_int_arg<b0>::b, }; public: enum { b = v0_ }; }; #endif // BOOST_BINARY_INT_HPP

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Re: [boost] VC 7.1/8.0 regression testing, call for volunteers (Was: [1.33.0] Status as of July 14)
by Rene Rivera 15 Jul '05

15 Jul '05

Carl Daniel wrote: > Aleksey Gurtovoy wrote: > >>Victor A. Wagner Jr. writes: >> >>>my system will be going offline until around 2005 August 1 in less >>>than 24 hours as I've reported previously (we're moving) >> >>Thanks for the heads up. >> >>Is somebody else able/willing to pick up regular VC 7.1/8.0 regression >>testing? > > I now have access to weekly builds of VC8 (currently testing the 7/11/2005 > build!). At the moment, it's not feasible to do boost regression testing on > those builds (it's a machine at MSFT), but I could look into getting it set > up. > > I now (once again) have the infrastructure in place locally to do boost > regression testing on VC8 beta 2, and/or VC8 June CTP. Unless someone else > volunteers, I can try to get my regression testing up and running again on > either or both of these builds. Is that a "willing to run vc8 tests but not vc71" ? For those volunteering it would be good to mention what resources you have available; CPU, memory, disk space, and machine time. As it takes a considerable amount of resources for testing, especially disk space. And having the faster machine and large ram will speed up the testing. I'm not trying to discourage people from volunteering though :-) Just want to make sure we keep up a reasonable testing pace. -- -- Grafik - Don't Assume Anything -- Redshift Software, Inc. - http://redshift-software.com -- rrivera/acm.org - grafik/redshift-software.com -- 102708583/icq - grafikrobot/aim - Grafik/jabber.org

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Re: [boost] weak_ptr triple states
by Jaap Suter 14 Jul '05

14 Jul '05

>> a weak_ptr can be said to have three states. >> 1. Never been assigned to (default constructed) >> 2. Assigned to, lock will return a shared_ptr to a valid object. >> 3. Assigned to, but the object pointed to is dead and lock will >> return null. > There is no particular reason to make 1 and 3 indistinguishable. You are > right that weak_ptr could have provided an "is empty" query in addition to > expired(). There just aren't any compelling use cases for it, as far as I > know. Are there compelling reasons not to add such a member function, i.e. a different shared_ptr implementation wouldn't be able to provide such a function? A friend of mine actually came up with a use case in his code, which is what prompted this question. In pseudo-code, it looked like this: struct guarded_memory { void* memory; weak_ptr guard; guarded_memory(void* m) : guard(), memory(m) {} guarded_memory(void* m, weak_ptr g) : guard(g), memory(m) {} void access() { if (guard.never_been_assigned_to_before()) { // no guard means always accessible do_something_with(memory); } else { if (shared_ptr p = guard.lock()) { do_something_with(memory); } } } }; Basically; if the user never provided a guard, the memory is deemed accesible at all times, otherwise accessibility depends on the liveliness of the pointed to guard. In my opinion, the code is ackwardly assymetrical and not an example of great design, but alas, it's what he came up with in some context. The solution to the above code is too add a litle boolean that remembers which of the two constructors has been called. This boolean is strictly speaking redundant because weak_ptr already stores this information. Hence my question. Thanks, Jaap Suter

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Type Traits Documentation Outdated?
by David Abrahams 14 Jul '05

14 Jul '05

It seems like the type traits docs have suffered some stagnation over time. For example, is it documented somewhere that almost all the traits are also Metafunctions? Also, the "guidelines for integral constant expressions" probably ought to be updated to recommend the use of MPL operations on integral constant wrappers instead of the baroque and long-winded ice_whatever templates. Thoughts? -- Dave Abrahams Boost Consulting www.boost-consulting.com

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Boost Wiki is corrupt
by Jody Hagins 14 Jul '05

14 Jul '05

Recent changes show... July 14, 2005 * (diff) BoostSocket/TimeValueConcept 11:10 am (2 changes) . . . . . 36.67-18-98.reverse.theplanet.com * (diff) BoostSocket/TimeValueConcept 11:10 am (2 changes) . . . . . 36.67-18-98.reverse.theplanet.com * (diff) BOOST WIKI 11:10 am (2 changes) . . . . . 36.67-18-98.reverse.theplanet.com * (diff) RecentChanges 11:10 am (2 changes) . . . . . 36.67-18-98.reverse.theplanet.com * (diff) RecentChanges 11:10 am (2 changes) . . . . . 36.67-18-98.reverse.theplanet.com

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Re: [boost] Interest in a binary_int template for binary literals?
by Scott Schurr 14 Jul '05

14 Jul '05

Greetings, David Abrahams wrote: > Scott Schurr <scott_schurr(a)credence.com> writes: > >>> * How does it deal with bit values like 0111? This is octal value. >> >> Right. There are specilizations for decimal and octal values. >> This means there is some aliasing. A few non-binary decimal and >> octal values leak through. For example 0111 (octal) is 73 decimal >> and, for that matter, 0x49 hex. So the template accepts all of >> these values. It's not perfect, but it's the best I could figure >> out. > > I think the answer is confusing. I don't know what "aliasing" means > in this case, but: aside from zero, the decimal numerals containing > all 1s and 0s have distinct values from the octal numerals containing > all 1s and 0s, at least up to something like 16 bits. There's no > ambiguity. Yes, my answer was confusing. Sorry. Let me try again. The template operates on values that look as though they should be binary, but are expressed in decimal or octal. For example: o 1001 - is a decimal value of one thousand and one, or 0x3E9. The template transforms this value to decimal 9, or 0x9. o 0010 - is an octal value that represents the decimal value eight, or 0x8. The template transforms this value to decimal 2, or 0x2. For legitimate binary representations like these, in decimal and octal, there is never any ambiguity of interpretation. I don't have a general proof, but the template only relies on no ambiguity for up to four digits. I have, in effect, an exhaustive proof in the code that there is no ambiguity up to four digits. My confusing reference to 'aliasing' could also be called spoofing. The template can be intentionally misused with certain magic values. For example, it interprets all of the following numeric values identically: 1001 == 0x3E9 == 01751 // the template converts all of these // (equivalent) values to decimal nine. Therefore... assert(binary_int<1001>::b == binary_int<01751>::b); would both compile and return true. But clearly, someone typing a value other than 1 or 0 in this template is misusing the template. The vast majority of numeric values that don't look like binary are rejected by the template and don't compile. I don't personally think the 'aliasing' aspect is any cause for alarm. If you use the template as intended it works well. And it is resistant to most misuses, just not all of them. Scott Schurr

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Boost regression notification (2005-07-14)
by Douglas Gregor 14 Jul '05

14 Jul '05

Boost regression test failures ------------------------------ Report time: 2005-07-14T15:02:22Z This report lists all regression test failures on release platforms. WARNING: The following libraries have failing regression tests but do not have a maintainer on file. Once a maintainer is found, add an entry to libs/maintainers.txt to eliminate this message. io Detailed report: http://engineering.meta-comm.com/boost-regression/CVS-HEAD/developer/issues… 299 failures in 8 libraries: io (1) parameter (13) program_options (3) random (2) serialization (266) spirit (3) test (6) wave (5) |io| ios_state_unit_test: intel-win32-8_1 |parameter| basics: gcc-3.2.3-linux gcc-3_3-darwin intel-win32-8_1 intel-win32-8_1 macros: gcc-3.2.3-linux gcc-3_3-darwin intel-win32-8_1 intel-win32-8_1 sfinae: gcc-3.2.3-linux gcc-3_3-darwin intel-win32-8_1 intel-win32-8_1 msvc |program_options| unicode_test_dll: cw-9_5-darwin gcc-3_3-darwin gcc-3_3-darwin |random| random_test: intel-win32-8_1 intel-win32-8_1 |serialization| test_class_info_load_binary_archive: gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_binary_archive_dll: gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_text_archive: cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_text_archive_dll: cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_text_warchive: cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_text_warchive_dll: cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux vc-6_5 test_class_info_load_xml_archive: gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_xml_archive_dll: gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_xml_warchive: cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux test_class_info_load_xml_warchive_dll: cw-9_5-darwin gcc-3.3.6-linux gcc-3.4.4-linux test_const_load_fail1: borland-5_6_4 test_const_load_fail1_nvp: borland-5_6_4 test_const_load_fail2: borland-5_6_4 test_const_load_fail2_nvp: borland-5_6_4 test_const_save_fail1: msvc vc-6_5 vc-6_5-stlport vc-7_0 test_const_save_fail2: msvc vc-6_5 vc-6_5-stlport vc-7_0 test_const_save_fail3: msvc vc-6_5 vc-6_5-stlport vc-7_0 test_demo_dll: cw-9_4 cw-9_4 test_demo_exception_dll: cw-9_4 cw-9_4 test_demo_fast_archive_dll: msvc vc-6_5 test_demo_pimpl_dll: msvc vc-6_5 vc-7_0 test_demo_portable_archive: intel-win32-8_1 intel-win32-8_1 vc-7_0 vc-7_1 vc-8_0 test_demo_portable_archive_dll: borland-5_6_4 intel-win32-8_1 intel-win32-8_1 test_demo_shared_ptr: cw-9_4 cw-9_4 cw-9_5-darwin test_demo_shared_ptr_dll: cw-9_4 cw-9_4 cw-9_5-darwin msvc vc-6_5 vc-7_0 test_diamond_binary_archive: cw-8_3 cw-9_5-darwin test_diamond_binary_archive_dll: cw-9_5-darwin test_diamond_text_archive: cw-8_3 cw-9_5-darwin test_diamond_text_archive_dll: cw-9_5-darwin test_diamond_text_warchive: cw-8_3 cw-9_5-darwin test_diamond_text_warchive_dll: cw-9_5-darwin test_diamond_xml_archive: cw-8_3 cw-9_5-darwin test_diamond_xml_archive_dll: cw-9_5-darwin test_diamond_xml_warchive: cw-8_3 cw-9_5-darwin test_diamond_xml_warchive_dll: cw-9_5-darwin test_map_binary_archive_dll: msvc vc-6_5 vc-7_0 test_map_text_archive_dll: msvc vc-6_5 vc-7_0 test_map_text_warchive_dll: msvc vc-6_5 vc-7_0 test_mult_archive_types: cw-9_4 cw-9_4 cw-9_5-darwin test_mult_archive_types_dll: cw-9_4 cw-9_4 cw-9_5-darwin msvc vc-6_5 test_non_default_ctor2_binary_archive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor2_binary_archive_dll: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor2_text_archive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor2_text_archive_dll: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor2_text_warchive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux test_non_default_ctor2_text_warchive_dll: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor2_xml_archive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor2_xml_archive_dll: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor2_xml_warchive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor2_xml_warchive_dll: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor_binary_archive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor_binary_archive_dll: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor_text_archive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor_text_archive_dll: cw-9_5-darwin gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor_text_warchive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux test_non_default_ctor_text_warchive_dll: cw-9_5-darwin gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor_xml_archive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor_xml_archive_dll: cw-9_5-darwin gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor_xml_warchive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_default_ctor_xml_warchive_dll: cw-9_5-darwin gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_intrusive_binary_archive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_intrusive_binary_archive_dll: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_intrusive_text_archive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_intrusive_text_archive_dll: cw-9_5-darwin gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_intrusive_text_warchive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux test_non_intrusive_text_warchive_dll: cw-9_5-darwin gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_intrusive_xml_archive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_intrusive_xml_archive_dll: cw-9_5-darwin gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_intrusive_xml_warchive: gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_non_intrusive_xml_warchive_dll: cw-9_5-darwin gcc-3.2.3-linux gcc-3.3.6-linux gcc-3.4.4-linux gcc-4.0.0-linux intel-8.1-linux test_shared_ptr_132_binary_archive: borland-5_6_4 test_shared_ptr_132_binary_archive_dll: borland-5_6_4 test_shared_ptr_132_text_archive: borland-5_6_4 test_shared_ptr_132_text_archive_dll: borland-5_6_4 test_shared_ptr_132_text_warchive: borland-5_6_4 test_shared_ptr_132_text_warchive_dll: borland-5_6_4 test_shared_ptr_132_xml_archive: borland-5_6_4 test_shared_ptr_132_xml_archive_dll: borland-5_6_4 test_shared_ptr_132_xml_warchive: borland-5_6_4 test_shared_ptr_132_xml_warchive_dll: borland-5_6_4 |spirit| action_tests: gcc-3_4_3-sunos action_tests_debug: gcc-3_4_3-sunos owi_mt_tests: gcc-3_3-darwin |test| errors_handling_test: cw-9_5-darwin vc-8_0 test_fp_comparisons: borland-5_6_4 test_tools_test: cw-9_4 cw-9_4 cw-9_5-darwin |wave| testwave: cw-8_3 cw-9_5-darwin gcc-3.2.3-linux gcc-3.3.6-linux gcc-3_4_3-sunos

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Re: [boost] [regex and string algo] again strange split behaviour
by Jan Hermelink 14 Jul '05

14 Jul '05

> It looks more like a bug than by design if you ask me. I don't think so - this behaviour is specified in the standardization proposal. To quote from http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2003/n1429.htm, Chapter "RE.8.2 Template class regex_token_iterator": "If the end of sequence is reached (regex_search returns false), the iterator becomes equal to the end-of-sequence iterator value, unless the sub-expression being enumerated has index -1: In which case the iterator enumerates one last string that contains all the characters from the end of the last regular expression match to the end of the input sequence being enumerated, provided that this would not be an empty string." !!! "provided that this would not be an empty string" !!! > I don't agree. > I think this is counterintuitive, both for string_algo and regex May be, but the above described behaviour has a good change to be standardized, and boost::split() should do the same thing. Jan -----Original Message----- From: boost-bounces(a)lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of Thore Karlsen Posted At: Wednesday, July 13, 2005 6:03 PM Posted To: Boost Developer Conversation: [boost] [regex and string algo] again strange split behaviour Subject: Re: [boost] [regex and string algo] again strange split behaviour On Wed, 13 Jul 2005 16:42:06 +0200, "Jan Hermelink" <Jan.Hermelink(a)metalogic.de> wrote: >The 1.32 behaviour is compatible with Boost.Regex: > >boost::regex_token_iterator in splitting mode returns for > >"abc/abc/" -> 2 tokens > >This is compatible with the regex standardization proposal. > >I think the behaviour of boost::split should be the same. I don't agree. I think this is counterintuitive, both for string_algo and regex. It looks more like a bug than by design if you ask me. -- Be seeing you. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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Re: [boost] [regex and string algo] again strange split behaviour
by Jan Hermelink 14 Jul '05

14 Jul '05

The 1.32 behaviour is compatible with Boost.Regex: boost::regex_token_iterator in splitting mode returns for "abc/abc/" -> 2 tokens This is compatible with the regex standardization proposal. I think the behaviour of boost::split should be the same. Regards, Jan -----Original Message----- From: boost-bounces(a)lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of Stefan Slapeta Posted At: Wednesday, July 13, 2005 3:13 PM Posted To: Boost Developer Conversation: [boost] [string algo] again strange split behaviour Subject: [boost] [string algo] again strange split behaviour hi, I assume the behaviour of boost::split not to return the last token has been changed (in CVS). However, a side effect seems to be that there is also one token returned for _empty_ strings, which is very questionable IMO! summary (if '/' is the separator): boost 1.32: "" -> 0 tokens "abc/abc" -> 2 tokens "abc/abc/" -> 2 tokens CVS: "" -> 1 token (!) "abc/abc" -> 2 tokens "abc/abc/" -> 3 tokens should be IMO: "" -> 0 tokens "abc/abc" -> 2 tokens "abc/abc/" -> 3 tokens Thoughts? Stefan _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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[Parameter] instance() causing lots of failures
by Douglas Gregor 14 Jul '05

14 Jul '05

Lines like this: keyword<name_>& name = instance(); are causing failures on lots of compilers. It looks like the workaround is simple, but we need to apply it to the platforms that are still failing... Doug

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