- Boost - lists.boost.org

RE: [boost] Re: On bind::operator==, again
by Powell, Gary 10 Mar '04

10 Mar '04

> but my recent >attempts to use Lambda have been a dismal failure, mostly because of >subtle (and sometimes not-so-subtle) differences with Bind. For >example, Lambda doesn't seem to support get_pointer to dereference >through smart pointers. Yeah, in the past I've had to bind the operator->() to the smart pointer argument and that looks plain ugly! Plus its not good for generic programming, you end up having to do some template magic to get it to call the right version, (native pointer * -> vs smart_ptr::operator->() ) >I'm rather discouraged with how difficult it is to use standard >algorithms -- or even algorithms over sequences as opposed to >iterators -- to write something that could be coded quickly using dumb >loops. Yep, me too. That's why we wrote lambda in the first place. And that's why I'm promoting decltype and auto, and varidac templates, and why its imperative we figure out how to do anonymous functions. >I hold out some hope that the long-promised integration of >Lambda and Phoenix will help to solve these problems, but it's hard >to tell when (or if) that's actually coming. That's the trouble with day jobs and mortgages vs free coding. Just not enough time in the day to do everything. >Glum in Somerville, >Dave Don't be glum soon you will be in Sunny Australia! Yours, -Gary-

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Re: [serialization17] demo_fast_binary_archive.cpp CANNOT compile in gcc 3.3.3
by Krishna Achuthan (TT) 10 Mar '04

10 Mar '04

David Abrahams wrote: >"Allen Yao" <yaozhen(a)ustc.edu> writes: > > > It seems that gcc does not allow this kind of template argument deduction: > > > > template <int N> > > void f(int a[N]) > > { > > for (int i = 0; i < N; i++) > > cout << a[i] << " "; > > cout << endl; > > } > > > > int main() > > { > > int a[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; > > > > f(a); > > } > > > > The error message is: > > > > error: no matching function for call to `f(int[10])' > > > > I would like to know how to fix this. Is there any workaround? > > Or if I am missing something? > > You're missing something. Your declaration of f is equivalent to: > > template <int N> > void f(int* a); > > try: > > template <int N> > void f(int a(&)[N]) > ^^^ > instead. > I tried both the original problem and the proposed solution on VC 7.1 For the original problem I got the following error messages: c:\Krishna\Console\Console7.cpp(242) : error C2784: 'void f(int [N])' : could not deduce template argument for 'int [N]' from 'int [10]' c:\Krishna\Console\Console7.cpp(207) : see declaration of 'f' And when I tried the proposed solution, I got the following error messages: c:\Krishna\Console\Console7.cpp(209) : error C2988: unrecognizable template declaration/definition c:\Krishna\Console\Console7.cpp(209) : error C2059: syntax error : '&' c:\Krishna\Console\Console7.cpp(209) : error C2090: function returns array c:\Krishna\Console\Console7.cpp(241) : error C2783: 'void f(int *(__cdecl *)(void))' : could not deduce template argument for 'N' c:\Krishna\Console\Console7.cpp(209) : see declaration of 'f' I did manage to find a work-around, which goes like this: template<class T> struct F; template<class T, int N> struct F<T[N]> { void operator()(T a[N]) { for (int i = 0; i < N; i++) cout << a[i] << " "; cout << endl; } }; template<class T> void f(T& a) { F<T>()(a); } int main() { int a[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; f(a); } Does it help? - Krishna Achuthan

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Implementing WaitForMultipleObjects using boost
by M Shetty 10 Mar '04

10 Mar '04

Hi, Is it possible to simulate a behaviour like WaitForMultipleObjects using boost? If yes, kindly let me know. Thanks and Regards, M Shetty ___________________________________________________ Check-out GO.com GO get your free GO E-Mail account with expanded storage of 6 MB! http://mail.go.com

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RE: Re: [boost] Implementing WaitForMultipleObjects using boost
by David Turner 10 Mar '04

10 Mar '04

Hi > I was checking out if I could use Boost to port code written > for Windows to Unix. > > The code has calls to WaitForMultipleObject which I would > need to replace. You can always do the same thing by means of conditions and signals. The paradigm is slightly different, though. //... boost::condition cond; object1.signal.connect(boost::bind(&boost::condition::notify_all, &cond)); object2.signal.connect(boost::bind(&boost::condition::notify_all, &cond)); cond.wait(mutex_lock); //... In this case, the objects have explicit signals (consider the parallel to windows kernel objects, which have an implicit "signal", i.e. their wait state). Regards David Turner

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[serialization17] demo_fast_binary_archive.cpp CANNOT compile in gcc 3.3.3
by Allen Yao 10 Mar '04

10 Mar '04

It seems that gcc does not allow this kind of template argument deduction: template <int N> void f(int a[N]) { for (int i = 0; i < N; i++) cout << a[i] << " "; cout << endl; } int main() { int a[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}; f(a); } The error message is: error: no matching function for call to `f(int[10])' I would like to know how to fix this. Is there any workaround? Or if I am missing something?

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vcapp & sgi regressions (string_algo)
by Pavol Droba 10 Mar '04

10 Mar '04

Hi, There are several problems reported by regression tests with the string_algo library on vcpp and mipspro compilers. I have no experience with these compilers and I wasn't able to figure out where the problem is from the error messages. 1. VCPP Following message is outputed: "/usr/vacpp/include/xmemory", line 120.23: 1540-0401 (S) The member "std::allocator<const char>::address(const_reference) const" is already declared. "/usr/vacpp/include/xmemory", line 118.17: 1540-0425 (I) "address" is defined on line 118 of "/usr/vacpp/include/xmemory". "/usr/vacpp/include/set", line 70.26: 1540-0700 (I) The previous message was produced while processing "class std::allocator<const char>". xlC -c -I/home/tk/boost_regression/boost -qNOOPTimize -qnoinline -g -qfullpath -qnotempinc -qfuncsect -qeh -qrtti -I"../bin/boost/libs/algorithm/string/test" -I"/home/tk/boost_regression/boost" -o "../bin/boost/libs/algorithm/string/test/find.test/vacpp/debug/find_test.o" "../libs/algorithm/string/test/find_test.cpp" It seems that the problem is triggered in my code by calling std::set<char>( char*, char* ) constructor. 2. MIPSPro In addtion to the following error in test framework: cc-1040 CC: ERROR File = /disk2/home/tk/boost_regression/boost/libs/test/src/test_tools.cpp, Line = 195 An identifier is expected. if( std::isprint( t ) ) ^ I'm getting similar error as with vcpp: cc-1377 CC: ERROR File = /usr/include/CC/stl_alloc.h, Line = 593 Member function function "std::allocator<const char>::address(std::allocator<const char>::reference) const" has already been declared. const_pointer address(const_reference __x) const { return &__x; } ^ A template was detected during header processing. instantiation of class "std::allocator<const char>" at line 92 of "/usr/include/CC/stl_set.h" instantiation of "std::set<const char, std::less<const char>, std::allocator<const char>>::set(const char *, const char *)" at line 74 of "/disk2/home/tk/boost_regression/boost/boost/algorithm/st ring/detail/classification.hpp" instantiation of "boost::algorithm::detail::is_any_ofF<const char>::is_any_ofF(const char (&)[4])" at line 201 of "/disk2/home/tk/boost_regression/boost/boost/algorithm/st ring/classification.hpp" instantiation of "boost::algorithm::detail::is_any_ofF<const char> boost::algorithm::is_any_of(const char (&)[4])" at line 143 of "../libs/algorithm/string/test/find_test.cpp" Can anybody help? Thanks, Pavol.

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What header is transform_iterator in?
by John Maddock 10 Mar '04

10 Mar '04

OK, I know the answer, but the doc page for transform_iterator doesn't say, even the example doesn't include any headers - I had to follow the link to the example source to double check. Other doc pages may have the same issue, I haven't checked. John.

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Re: Re: [boost] Implementing WaitForMultipleObjects using boost
by M Shetty 10 Mar '04

10 Mar '04

Hi, I was checking out if I could use Boost to port code written for Windows to Unix. The code has calls to WaitForMultipleObject which I would need to replace. Thanks and Regards, M Shetty -----Original Message----- From: "Jeremy Maitin-Shepard"<jbms(a)attbi.com> To: boost(a)lists.boost.org Date: Tue Mar 09 17:57:04 PST 2004 Subject: Re: [boost] Implementing WaitForMultipleObjects using boost >No, but why would you want to simulate it? > >-- >Jeremy Maitin-Shepard >_______________________________________________ >Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost ___________________________________________________ Check-out GO.com GO get your free GO E-Mail account with expanded storage of 6 MB! http://mail.go.com

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_POSIX_C_SOURCE redefinition warning with python 2.3 and boost-1.31.0
by Peter Hornby 10 Mar '04

10 Mar '04

Sorry if this has been mentioned before. the following patch against boost-1.31.0 silences the warnings on linux, but I have not tested that there are no side-effects on other compilers. --------------------------------START PATCH------------------------ Index: boost/python/detail/wrap_python.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/python/detail/wrap_python.hpp,v retrieving revision 1.17 diff -p -r1.17 wrap_python.hpp *** boost/python/detail/wrap_python.hpp 1 May 2003 05:19:47 -0000 1.17 --- boost/python/detail/wrap_python.hpp 1 Mar 2004 05:36:49 -0000 *************** *** 23,28 **** --- 23,29 ---- // // Python's LongObject.h helpfully #defines ULONGLONG_MAX for us, // which confuses Boost's config + // Also kill any definition of _POSIX_C_SOURCE so Python.h can determine it. // #include <limits.h> #ifndef ULONG_MAX *************** *** 34,39 **** --- 35,44 ---- #ifndef ULONGLONG_MAX # define BOOST_PYTHON_ULONGLONG_MAX_UNDEFINED #endif + #ifdef _POSIX_C_SOURCE + # undef _POSIX_C_SOURCE + #endif + // // Get ahold of Python's version number --------------------------------END PATCH------------------------ Index: boost/python/detail/wrap_python.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/python/detail/wrap_python.hpp,v retrieving revision 1.17 diff -p -r1.17 wrap_python.hpp *** boost/python/detail/wrap_python.hpp 1 May 2003 05:19:47 -0000 1.17 --- boost/python/detail/wrap_python.hpp 1 Mar 2004 05:36:49 -0000 *************** *** 23,28 **** --- 23,29 ---- // // Python's LongObject.h helpfully #defines ULONGLONG_MAX for us, // which confuses Boost's config + // Also kill any definition of _POSIX_C_SOURCE so Python.h can determine it. // #include <limits.h> #ifndef ULONG_MAX *************** *** 34,39 **** --- 35,44 ---- #ifndef ULONGLONG_MAX # define BOOST_PYTHON_ULONGLONG_MAX_UNDEFINED #endif + #ifdef _POSIX_C_SOURCE + # undef _POSIX_C_SOURCE + #endif + // // Get ahold of Python's version number

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Re:Re: [boost]Re: Re: [serialization] non-conformance
by Robert Ramey 10 Mar '04

10 Mar '04

>Robert Ramey wrote: >> This exchange illustrates the problem rather nicely. Its not clear >> to me from the name "aligned_storage" that its meant to do the same >> job as "stack_allocate" and in fact is easily confused with other >> boost functions. I've been able to find no documentation nor test >> nor other information. The only place its used is in variant.hpp but >> its not mentioned in the documentation of that either. There is no >> statement in the header itself as to what it does and the code is >> sufficiently non-trivial that it's not obvious what its supposed to >> do. The fact that it has a parameter than stack_allocate doesn't >> need also suggests that it's intended purpose is different from that >> of stack_allocate. The previous post referred to alignment_of rather than aligned_storage which seems to me to unrelated. Are they related in some non-obvious (to me) way? What's incorrect about my statement above? >It doesn't, see aligned_storage's "Rationale" subsection in >http://tinyurl.com/39asx. Is this part of boost documentation and tests? Robert Ramey

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