June 2002 - Boost-users - lists.preview.boost.org

Problems getting subexpressions in regex_search
by soleani 30 Jun '02

30 Jun '02

Hi all, This is the test program: #include <boost/regex.hpp> #include <iostream> #include <string> int main() { static const boost::regex regexRedirectedSection( "\\[(.+?) \\s*=\\s*<(.+?):(.+?)>\\]", boost::regbase::perl ); std::string input = "[MY_SECTION = <FILE:SECTION>]"; boost::cmatch what; if ( boost::regex_search( input, what, regexRedirectedSection, boost::regbase::perl ) ) { cerr << "Matched new style section redirection!!!! Input is: " << input << endl; cerr << "0 gives: --" << what[0].first << "-- and second: " << what[0].second << endl; cerr << "1 gives: --" << what[1].first << "-- and second: " << what[1].second << endl; cerr << "2 gives: --" << what[2].first << "-- and second: " << what[2].second << endl; cerr << "3 gives: --" << what[3].first << "-- and second: " << what[3].second << endl; } return 0; } This is the output: [anibal@anibal ControlFile]$ ./match Matched new style section redirection!!!! Input is: [MY_SECTION = <FILE:SECTION>] 0 gives: --[MY_SECTION = <FILE:SECTION>]-- and second: 1 gives: --MY_SECTION = <FILE:SECTION>]-- and second: = <FILE:SECTION>] 2 gives: --FILE:SECTION>]-- and second: :SECTION>] 3 gives: --SECTION>]-- and second: >] I don't understand why $1 is not giving my MY_SECTION only. It looks like the non-greedy operator is not working as I expect it. This same expression works in Perl and jakarta's regex engine in Java. I basically need to extract MY_SECTION, FILE, and SECTION from the input string. Any pointers as to what's going on will be greatly appreciated. -Anibal

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RE: [Boost-Users] Win2k / NT Spell Check Wrapper
by Jim.Hyslop 29 Jun '02

29 Jun '02

Jer (yg-boost-users(a)gmane.org) wrote: > Hi all, > > My first time posting or visiting here. Please note that this list is for discussion of the Boost library, not for general programming discussions. In general, it is considered good etiquette to research what is considered "on topic" for a newsgroup or mail list, before you post to it. Please read the information at http://groups.yahoo.com/group/Boost-Users/ Thank you. -- Jim Hyslop moderator, boost-users(a)yahoogroups.com

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Win2k / NT Spell Check Wrapper
by Jer 28 Jun '02

28 Jun '02

Hi all, My first time posting or visiting here. I'm trying to find out if anyone has ever worked with the spell checker .dll and .dic files that come with Win 2k / NT. I'm desiring to wrap / call this via VB or Lotus Script for a web application. I'm a newbie c++ programmer, but I'm learning fairly quickly. Any help or useful suggestions would be greatly appreciated. Kind regards, Jer -- "Proceed with wisdom, humility and honesty."

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Re: [Boost-Users] Re: boost::polymorphic_upcast suggestion
by Sam Partington 28 Jun '02

28 Jun '02

Sorry, don't know what happened then, I'll continue... class A {}; class B {}; class C : public A, public B {}; int main(int argc, char* argv[]) { C c; C* pc = &c; //B* pb = boost::polymorphic_downcast<B*>( pc ); // this cast is unnecessary, the compiler <knows> that C isa B at compile time, // so it can go ahead and upcast it without asking you or the runtime type info: B* pb = pc; // C* pc2 = polymorphic_upcast<C*>( pb); // this is precisely where the boost::polymorphic_downcast is intended to be used, // ie Cast a Base (ptr or ref) to a Derived (ptr or ref) // the compiler doesn't know that a B object is definately a valid C, so it requires you to // qualify it, using some kind of cast. C* pc2 = boost::polymorphic_downcast<C*>(pb); return 0; } So thats downcasting and upcasting, there is no need for a polymorphic_upcast, as it is implicity done and can be tested for at compile time. The only other cast not covered here is cross casting, which is what boost::polymorphic_cast is designed for, but I find that almost everytime I come across a use of a cross cast it is due to a design flaw. (the same could also be said to a lesser extent about downcasting) Hope this clears things up a bit. Sam > > -----Original Message----- > > From: news [mailto:news@main.gmane.org]On Behalf Of Jean Llorca > > Sent: 27 June 2002 15:31 > > To: boost-users(a)yahoogroups.com > > Subject: [Boost-Users] Re: boost::polymorphic_upcast suggestion > > > > > > "Darin Adler" <darin(a)bentspoon.com> a écrit dans le message de news: > > B586F909-89D7-11D6-9349-0003935B80A2(a)bentspoon.com... > > > > > > On Thursday, June 27, 2002, at 06:38 AM, Jean Llorca wrote: > > > > > > > Here upcasting means casting a base class to a derived class, I know > > > > it may seem strange, bust boost offers a downcast > > > > which does the static_cast the language does implicitly > already (check > > > > <boost/cast.hpp>). > > > > > > I think you've got it backwards. Downcasting, in Boost at least, means > > > casting a pointer to a base class part of an object to a pointer to a > > > derived class part of the same object. The polymorphic_downcast is > > > *not* doing a static_cast for a conversion the language already does > > > implicitly. > > > > template <class Target, class Source> > > inline Target polymorphic_downcast(Source* x > > BOOST_EXPLICIT_DEFAULT_TARGET) > > { > > assert( dynamic_cast<Target>(x) == x ); // detect logic error > > return static_cast<Target>(x); > > } > > > > Sorry about it, but it's here in the code. This is in the last > version of > > the CVS. It does a static_cast. The compiler does static_cast > > implicitly in > > some cases. > > For instance a C++ compiler replaces the assert line with: > > assert( dynamic_cast<Target>(x) == static_cast<Target>(x) ); > > > > > > > > Could you give a specific complete example (a file that would compile, > > > with all the declarations) of how one would use what you're proposing > > > to help make this clearer? > > > > I enclosed two files to this reply. Don't scream about chosen > class names > > and stuff in the example ;)

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boost::bind for member functions
by Bill Dozier 27 Jun '02

27 Jun '02

Hi, I'd like to be able to bind an object to to a member function argument, like the example below. NB: if I make not_ok()'s first argument an int and pass an int variable to bind, gcc will buy it. I've tried this every way that makes any sense to me and I have not been able to get it to work. I'm using gcc 2.95.3. Thanks, Bill #include <boost/bind.hpp> #include <boost/function.hpp> class D { private: int _d; public: D() :_d(0) {} int d() const { return _d; } void d(int i) { _d = i; } }; typedef boost::function<int, int> Foo; class A { private: Foo _f; public: A(Foo f) :_f(f) {} int doit(int i) { return _f(i); } }; class B { public: int not_ok(const D *d, int j) { return d->d() + j; } }; class C { public: int ok(int i) { return i * i; } }; int fooBar(int j); static Foo g = fooBar; int fooBar(int j) { B *b = new B; C *c = new C; Foo f1 = boost::bind(&C::ok, c, _1); A a1(f1); int i = 5; D *d = new D; d->d(3); Foo f2 = boost::bind(&B::not_ok, b, _1, d); //<----- A a2(f2); return a1.doit(i) + a2.doit(2); } /usr/local/devl/src/incl/boost/bind.hpp: In method `int boost::_bi::list3<boost::_bi::value<B *>,boost::arg<1>,boost::_bi::value<D *> >::operator ()<int, boost::_mfi::mf2<int,B,const D *,int>, boost::_bi::list1<int &> >(boost::_bi::type<int>, boost::_mfi::mf2<int,B,const D *,int>, boost::_bi::list1<int &> &) const': /usr/local/devl/src/incl/boost/bind/bind_template.hpp:33: instantiated from `boost::_bi::bind_t<int,boost::_mfi::mf2<int,B,const D *,int>,boost::_bi::list3<boost::_bi::value<B *>,boost::arg<1>,boost::_bi::value<D *> > >::operator ()<int>(int &)' /usr/local/devl/src/incl/boost/function/function_template.hpp:110: instantiated from `boost::detail::function::function_obj_invoker1<boost::_bi::bind_t<int,boost::_mfi::mf2<int,B,const D *,int>,boost::_bi::list3<boost::_bi::value<B *>,boost::arg<1>,boost::_bi::value<D *> > >,int,int>::invoke(boost::detail::function::any_pointer, int)' /usr/local/devl/src/incl/boost/function/function_template.hpp:437: instantiated from `boost::function1<int,int,boost::empty_function_policy,boost::empty_function_mixin,allocator<boost::function_base> >::assign_to<boost::_bi::bind_t<int,boost::_mfi::mf2<int,B,const D *,int>,boost::_bi::list3<boost::_bi::value<B *>,boost::arg<1>,boost::_bi::value<D *> > > >(boost::_bi::bind_t<int,boost::_mfi::mf2<int,B,const D *,int>,boost::_bi::list3<boost::_bi::value<B *>,boost::arg<1>,boost::_bi::value<D *> > >, boost::detail::function::function_obj_tag)' /usr/local/devl/src/incl/boost/function/function_template.hpp:388: instantiated from `boost::function1<int,int,boost::empty_function_policy,boost::empty_function_mixin,allocator<boost::function_base> >::assign_to<boost::_bi::bind_t<int,boost::_mfi::mf2<int,B,const D *,int>,boost::_bi::list3<boost::_bi::value<B *>,boost::arg<1>,boost::_bi::value<D *> > > >(boost::_bi::bind_t<int,boost::_mfi::mf2<int,B,const D *,int>,boost::_bi::list3<boost::_bi::value<B *>,boost::arg<1>,boost::_bi::value<D *> > >)' /usr/local/devl/src/incl/boost/function/function_template.hpp:274: instantiated from `boost::function1<int,int,boost::empty_function_policy,boost::empty_function_mixin,allocator<boost::function_base> >::function1<boost::_bi::bind_t<int,boost::_mfi::mf2<int,B,const D *,int>,boost::_bi::list3<boost::_bi::value<B *>,boost::arg<1>,boost::_bi::value<D *> > > >(boost::_bi::bind_t<int,boost::_mfi::mf2<int,B,const D *,int>,boost::_bi::list3<boost::_bi::value<B *>,boost::arg<1>,boost::_bi::value<D *> > >)' /usr/local/devl/src/incl/boost/function.hpp:459: instantiated from `boost::function<int,int,boost::detail::function::unusable,boost::detail::function::unusable,boost::detail::function::unusable,boost::detail::function::unusable,boost::detail::function::unusable,boost::detail::function::unusable,boost::detail::function::unusable,boost::detail::function::unusable,boost::detail::function::unusable>::function<boost::_bi::bind_t<int,boost::_mfi::mf2<int,B,const D *,int>,boost::_bi::list3<boost::_bi::value<B *>,boost::arg<1>,boost::_bi::value<D *> > > >(boost::_bi::bind_t<int,boost::_mfi::mf2<int,B,const D *,int>,boost::_bi::list3<boost::_bi::value<B *>,boost::arg<1>,boost::_bi::value<D *> > >)' testBoost.C:61: instantiated from here /usr/local/devl/src/incl/boost/bind.hpp:263: no match for call to `(boost::_mfi::mf2<int,B,const D *,int>) (B *const &, int &, D *const &)' /usr/local/devl/src/incl/boost/bind/mem_fn_template.hpp:212: candidates are: int boost::_mfi::mf2<int,B,const D *,int>::operator ()(B *, const D *, int) const /usr/local/devl/src/incl/boost/bind/mem_fn_template.hpp:217: int boost::_mfi::mf2<int,B,const D *,int>::operator ()<B *const>(B *const &, const D *, int) const /usr/local/devl/src/incl/boost/bind/mem_fn_template.hpp:222: int boost::_mfi::mf2<int,B,const D *,int>::operator ()(B &, const D *, int) const /usr/local/devl/src/incl/boost/bind.hpp:263: warning: control reaches end of non-void function `boost::_bi::list3<boost::_bi::value<B *>,boost::arg<1>,boost::_bi::value<D *> >::operator ()<int, boost::_mfi::mf2<int,B,const D *,int>, boost::_bi::list1<int &> >(boost::_bi::type<int>, boost::_mfi::mf2<int,B,const D *,int>, boost::_bi::list1<int &> &) const'

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RE: [Boost-Users] boost::polymorphic_upcast suggestion
by Jim.Hyslop 27 Jun '02

27 Jun '02

Jean Llorca (yg-boost-users(a)gmane.org) wrote: > I would like to propose, in the spirit of Bjarne Stroustrup book, > an upcast (where target inherits source). Upcasting is already directly supported by the language. Given classes Base and Derived, with the public inheritance implied by their names, then: Derived d; Base * b=&d; Base & br = d; will work without any casting whatsoever. When the compiler compiles this code, it has the definitions of classes Base and Derived available, so all the work can be performed at compile time. > template <class Target, class Source> > inline Target polymorphic_upcast(Source* x > BOOST_EXPLICIT_DEFAULT_TARGET) > { > > typedef unsigned int uint; > > > uint offset = reinterpret_cast<uint>( static_cast<Source*>( > reinterpret_cast<Target>(1) ) ) - 1; > Target res = reinterpret_cast<Target>( > reinterpret_cast<uint>( x ) - > offset ); > > assert( res == dynamic_cast<Target>(x) ); > > return res; > } I don't understand this - how is casting a Target to an unsigned int going to help? Did you perhaps mean Target * in the above example, or have I missed something? -- Jim

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boost::polymorphic_upcast suggestion
by Jean Llorca 27 Jun '02

27 Jun '02

Hi, I would like to propose, in the spirit of Bjarne Stroustrup book, an upcast (where target inherits source). template <class Target, class Source> inline Target polymorphic_upcast(Source* x BOOST_EXPLICIT_DEFAULT_TARGET) { typedef unsigned int uint; uint offset = reinterpret_cast<uint>( static_cast<Source*>( reinterpret_cast<Target>(1) ) ) - 1; Target res = reinterpret_cast<Target>( reinterpret_cast<uint>( x ) - offset ); assert( res == dynamic_cast<Target>(x) ); return res; } It would be faster to use the polymorphic_upcast, since it doesn't use dynamic_cast in NDEBUG. Regards, Jean Llorca.

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RegEx++ and vc7 heap/memory error
by john_p_osborn 26 Jun '02

26 Jun '02

When executing the following code I get an _CrtIsValidHeapPointer error in dbgheap.c: boost::RegEx r; std:string sTmp; std:string sExp = "\\bContent-Type:":\\s*([^; ]{1,16})""; r.SetExpression(sExp, true); if (!r.Search((LPCTSTR)(pInputBytes))) { ... error } else { sTmp = r2[1]; } If I change sExp to specify {1,15} it works. Anybody know what's going on? I'm using 1_28_0 with Visual Studio .NET

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Regex problems with HP aCC
by dufr0017 26 Jun '02

26 Jun '02

I am trying to build the Regex library for hp_ux 11.0 using aCC version 3.33. I have tried both the current CVS version and version 1.28 of Boost. With either one, I get the same errors. Below is the full text of my error message. I have been able to build successfully on many other platforms. I found a message in the archives, accessible at http://lists.boost.org/MailArchives/boost/msg29179.php, where another user has experienced a similar problem. Has anyone solved this problem, or could any offer a possible fix? Is anyone using Regex on HP_UX? If so, any tips on configuration, etc, would be greatly appreciated. I am stumped by this one. Thanks in advance for your help, Mark Dufresne Here is the error: aCC -o hp_ux/boost_regex/cregex.o -c -I../../../ +Z -AA -mt +DAportable -g0 +W749 ../src/cregex.cpp Error 619: "../../../boost/regex/detail/regex_match.hpp", line 1781 # The definition of template iterator_traits<boost::detail::allocator_adapter<char,boost::detail::s imple_alloc> > contains typename qualification '_Iterator::iterator_category', yet generation of specialization struct iterator_traits<boost::detail::allocator_adapter<char,boost::detail::s imple_alloc> > implies that '_Iterator' is 'class allocator_adapter<char,boost::detail::simple_alloc>', which does not contain a type named 'iterator_category'. return re_detail::reg_grep(re_detail::grep_search_predicate<iterator, ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Error 618: Exact position unknown; near ["../../../boost/regex/detail/regex_match.hpp", line 1781]. # The definition of template iterator_traits<template#0> contains typename qualification '_Iterator::value_type', yet generation of specialization struct iterator_traits<template#0> implies that '_Iterator' is 'tentative class template#0', which is incomplete. Error 445: "../../../boost/regex/detail/regex_match.hpp", line 1781 # Cannot recover from earlier errors. return re_detail::reg_grep(re_detail::grep_search_predicate<iterator, ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ *** Error exit code 2

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boost.python and g++ 3.1 - Help needed
by jfo60540 26 Jun '02

26 Jun '02

Hi - I am trying to recompile code that compiles cleanly with g++ 3.0.4 with g++ 3.1. I get the following error messages, which, I am affraid, I cannot decipher. Any hints would be greatly appreciated. -Francois g++ -c -g -fPIC -DBOOST -I/usr/local/ap/include/python2.2 -I/usr/local/ap/PLplot/include -I/usr/local/ap/galib/include -o pymathlib.o pymathlib.cc/usr/local/ap/include/boost/python/cross_module.hpp: In instantiation of `SuperCode::Vector<Real>& boost::python::from_python(PyObject*, boost::python::type<SuperCode::Vector<Real>&>, bool)': /usr/local/ap/include/boost/python/caller.hpp:1093: instantiated from `static PyObject* boost::python::caller<void>::call(void (*)(A1, A2, A3), PyObject*, PyObject*) [with A1 = SuperCode::Vector<Real>&, A2 = const SuperCode::Vector<Real>&, A3 = const SuperCode::Vector<Real>&]' /usr/local/ap/include/boost/python/detail/functions.hpp:73: instantiated from `PyObject* boost::python::detail::wrapped_function_pointer<R, F>::do_call(PyObject*, PyObject*) const [with R = Void, F = Void (*)(SuperCode::Vector<Real>&, const SuperCode::Vector<Real>&, const SuperCode::Vector<Real>&)]' /usr/local/ap/include/boost/function/function_base.hpp:153: instantiated from here /usr/local/ap/include/boost/python/cross_module.hpp:91: default argument given for parameter 3 of `SuperCode::Vector<Real>& boost::python::from_python(PyObject*, boost::python::type<SuperCode::Vector<Real>&>, bool = false)' /usr/local/ap/include/boost/python/cross_module.hpp:91: after previous specification in `SuperCode::Vector<Real>& boost::python::from_python(PyObject*, boost::python::type<SuperCode::Vector<Real>&>, bool = false)' /usr/local/ap/include/boost/python/cross_module.hpp: In instantiation of `const SuperCode::Vector<Real>& boost::python::from_python(PyObject*, boost::python::type<const SuperCode::Vector<Real>&>, bool)': /usr/local/ap/include/boost/python/caller.hpp:1093: instantiated from `static PyObject* boost::python::caller<void>::call(void (*)(A1, A2, A3), PyObject*, PyObject*) [with A1 = SuperCode::Vector<Real>&, A2 = const SuperCode::Vector<Real>&, A3 = const SuperCode::Vector<Real>&]' /usr/local/ap/include/boost/python/detail/functions.hpp:73: instantiated from `PyObject* boost::python::detail::wrapped_function_pointer<R, F>::do_call(PyObject*, PyObject*) const [with R = Void, F = Void (*)(SuperCode::Vector<Real>&, const SuperCode::Vector<Real>&, const SuperCode::Vector<Real>&)]' /usr/local/ap/include/boost/function/function_base.hpp:153: instantiated from here /usr/local/ap/include/boost/python/cross_module.hpp:94: default argument given for parameter 3 of `const SuperCode::Vector<Real>& boost::python::from_python(PyObject*, boost::python::type<const SuperCode::Vector<Real>&>, bool = false)' /usr/local/ap/include/boost/python/cross_module.hpp:94: after previous specification in `const SuperCode::Vector<Real>& boost::python::from_python(PyObject*, boost::python::type<const SuperCode::Vector<Real>&>, bool = false)'

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