[Boost-users] xpressive: set vs standard alternation compile problems

From: Zachary (unceldrot_at_[hidden])
Date: 2008-02-19 11:15:50

Hi,
  I'm a new user of xpresssive and I'd like to first give a big thank 
you for this wonderful tool.

 I'm having problems with the syntax for static regexes.  The cheat 
sheet in the documentation says that |(set= 'a','b','c')| and 
|as_xpr('a') | 'b' |'c'| are equivalent yet the example

    sregex parentheses;

    parentheses = '(' >> *(keep(+~(boost::xpressive::set='(',')'))|by_ref(parentheses)) >> ')';

compiles while

    sregex parentheses;

    parentheses = '(' >> *(keep(+~(as_xpr('(')|')'))|by_ref(parentheses)) >> ')';

fails to do so (code and abbreviated errors attached).  Additionally, 
combining the original lines into one construction, like so:

    sregex parentheses = '(' >> *(keep(+~(boost::xpressive::set='(',')'))|by_ref(parentheses)) >> ')';

compiles but running the code fails with:

    regnestest: /usr/include/boost/xpressive/detail/utility/tracking_ptr.hpp:457:
     const boost::shared_ptr<T>& boost::xpressive::detail::tracking_ptr<Type>::get_(bool) const [with Type = boost::xpressive::detail::regex_impl<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >]:
     Assertion `!this->has_deps_()' failed.
      

and using as_xpr for the first term:

    sregex parentheses = as_xpr('(') >> *(keep(+~(boost::xpressive::set='(',')'))|by_ref(parentheses)) >> ')';
      

also compiles but causes a seg fault when run!

All this is using g++ 4.2.3 and boost 1.34 as packaged with Debian 
testing.  These seem like library errors to me, but like I said, I'm new 
to xpressive, and I'd be even happier to have my understanding improved.

Zachary


g++ -MMD    regnestest.cpp   -o regnestest
/usr/include/boost/xpressive/detail/static/productions/complement_compiler.hpp: In instantiation of ‘boost::xpressive::detail::complement<boost::proto::binary_op<boost::proto::unary_op<boost::xpressive::detail::literal_placeholder<char, false>, boost::proto::noop_tag>, boost::proto::unary_op<char, boost::proto::noop_tag>, boost::proto::bitor_tag>, boost::xpressive::detail::xpression_visitor<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, mpl_::bool_<false>, boost::xpressive::cpp_regex_traits<char> > >’:
/usr/include/boost/xpressive/detail/static/productions/complement_compiler.hpp:227:   instantiated from ‘boost::xpressive::detail::complement_transform::apply<boost::proto::unary_op<boost::proto::binary_op<boost::proto::unary_op<boost::xpressive::detail::literal_placeholder<char, false>, boost::proto::noop_tag>, boost::proto::unary_op<char, boost::proto::noop_tag>, boost::proto::bitor_tag>, boost::proto::complement_tag>, boost::xpressive::detail::static_xpression<boost::xpressive::detail::true_matcher, boost::xpressive::detail::no_next>, boost::xpressive::detail::xpression_visitor<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, mpl_::bool_<false>, boost::xpressive::cpp_regex_traits<char> > >’
/usr/include/boost/xpressive/proto/compiler/transform.hpp:65:   instantiated from ‘boost::proto::transform_compiler<boost::xpressive::detail::complement_transform, boost::xpressive::detail::seq_tag, void>::apply<boost::proto::unary_op<boost::proto::binary_op<boost::proto::unary_op<boost::xpressive::detail::literal_placeholder<char, false>, boost::proto::noop_tag>, boost::proto::unary_op<char, boost::proto::noop_tag>, boost::proto::bitor_tag>, boost::proto::complement_tag>, boost::xpressive::detail::static_xpression<boost::xpressive::detail::true_matcher, boost::xpressive::detail::no_next>, boost::xpressive::detail::xpression_visitor<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, mpl_::bool_<false>, boost::xpressive::cpp_regex_traits<char> > >’
/usr/include/boost/xpressive/proto/compiler/transform.hpp:74:   instantiated from ‘boost::proto::transform_compiler<boost::proto::arg_transform, boost::xpressive::detail::seq_tag, void>::apply<boost::proto::unary_op<boost::proto::unary_op<boost::proto::binary_op<boost::proto::unary_op<boost::xpressive::detail::literal_placeholder<char, false>, boost::proto::noop_tag>, boost::proto::unary_op<char, boost::proto::noop_tag>, boost::proto::bitor_tag>, boost::proto::complement_tag>, boost::proto::unary_plus_tag>, boost::xpressive::detail::static_xpression<boost::xpressive::detail::true_matcher, boost::xpressive::detail::no_next>, boost::xpressive::detail::xpression_visitor<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, mpl_::bool_<false>, boost::xpressive::cpp_regex_traits<char> > >’
/usr/include/boost/xpressive/proto/compiler/branch.hpp:37:   instantiated from ‘boost::proto::branch_compiler<boost::xpressive::detail::simple_repeat_branch<true, 1u, 4294967294u>, boost::xpressive::detail::ind_tag>::apply<boost::proto::unary_op<boost::proto::unary_op<boost::proto::binary_op<boost::proto::unary_op<boost::xpressive::detail::literal_placeholder<char, false>, boost::proto::noop_tag>, boost::proto::unary_op<char, boost::proto::noop_tag>, boost::proto::bitor_tag>, boost::proto::complement_tag>, boost::proto::unary_plus_tag>, boost::xpressive::detail::static_xpression<boost::xpressive::detail::true_matcher, boost::xpressive::detail::no_next>, boost::xpressive::detail::xpression_visitor<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, mpl_::bool_<false>, boost::xpressive::cpp_regex_traits<char> > >’
/usr/include/boost/xpressive/proto/compiler/conditional.hpp:40:   instantiated from ‘boost::proto::conditional_compiler<boost::xpressive::detail::use_simple_repeat_predicate, boost::proto::branch_compiler<boost::xpressive::detail::simple_repeat_branch<true, 1u, 4294967294u>, boost::xpressive::detail::ind_tag>, boost::proto::transform_compiler<boost::proto::compose_transforms<boost::proto::arg_transform, boost::xpressive::detail::repeater_if_transform<true, 1u, 4294967294u> >, boost::xpressive::detail::seq_tag, void> >::apply<boost::proto::unary_op<boost::proto::unary_op<boost::proto::binary_op<boost::proto::unary_op<boost::xpressive::detail::literal_placeholder<char, false>, boost::proto::noop_tag>, boost::proto::unary_op<char, boost::proto::noop_tag>, boost::proto::bitor_tag>, boost::proto::complement_tag>, boost::proto::unary_plus_tag>, boost::xpressive::detail::static_xpression<boost::xpressive::detail::true_matcher, boost::xpressive::detail::no_next>, boost::xpressive::detail::xpression_visitor<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, mpl_::bool_<false>, boost::xpressive::cpp_regex_traits<char> > >’

--snipped for brevity--

regnestest.cpp:10:   instantiated from here

--subsequent errors omitted for brevity--