Станд :: basic_regex , Кто-то уже пытается это сделать?

2:

#include <iostream>
#include <string>
#include <regex>
int main() {
 std::u32string lines[] = {U"Roses are #ff0000",
 U"violets are #0000ff",
 U"all of my base are belong to you"};

 std::basic_regex<char32_t> color_regex(U"#([a-f0-9]{2})([a-f0-9]{2})([a-f0-9]{2})");
 /*
 for (const auto &line : lines) {
 std::cout << line << ": " 
 << std::regex_search(line, color_regex) << '\n';
 }
 std::smatch color_match;
 for (const auto &line : lines) {
 std::regex_search(line, color_match, color_regex);
 std::cout << "matches for '" << line << "'\n";
 for (size_t i = 0; i < color_match.size(); ++i) {
 std::ssub_match sub_match = color_match[i];
 std::string sub_match_str = sub_match.str();
 std::cout << i << ": " << sub_match_str << '\n';
 }
 }
 */
 return 0;
}
</char32_t></regex></string></iostream>

скомпилировать с gcc: он работает:

g++ -g -O0 -std=c++11 regexp.cpp -o executable

компилировать с clang: он вообще не работает:

clang++ -g -O0 -std=c++11 regexp.cpp -o executable

выполнить с gcc сгенерированным файлом:

terminate called after throwing an instance of 'std::bad_cast'
 what(): std::bad_cast
Abandon (core dumped)

ошибка в компиляции clang:

In file included from regexp.cpp:3:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/regex:60:
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/regex_compiler.h:413:20: error: non-type template argument is not a constant expression
 std::bitset<1 << (8 * sizeof(_CharT))>,
 ^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/regex_compiler.tcc:398:53: note: in instantiation of template class 'std::__detail::_BracketMatcher<std::regex_traits<char32_t>, false, false>' requested here
 _BracketMatcher<_TraitsT, __icase, __collate> __matcher
 ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/regex_compiler.tcc:316:25: note: in instantiation of function template specialization 'std::__detail::_Compiler<std::regex_traits<char32_t>
 >::_M_insert_character_class_matcher<false, false="">' requested here
 __INSERT_REGEX_MATCHER(_M_insert_character_class_matcher);
 ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/regex_compiler.tcc:288:8: note: expanded from macro '__INSERT_REGEX_MATCHER'
 __func<false, false="">(args);\
 ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/regex_compiler.tcc:136:17: note: in instantiation of member function 'std::__detail::_Compiler<std::regex_traits<char32_t> >::_M_atom' requested here
 if (this->_M_atom())
 ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/regex_compiler.tcc:118:17: note: in instantiation of member function 'std::__detail::_Compiler<std::regex_traits<char32_t> >::_M_term' requested here
 if (this->_M_term())
 ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/regex_compiler.tcc:97:13: note: in instantiation of member function 'std::__detail::_Compiler<std::regex_traits<char32_t> >::_M_alternative' requested here
 this->_M_alternative();
 ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/regex_compiler.tcc:82:13: note: in instantiation of member function 'std::__detail::_Compiler<std::regex_traits<char32_t> >::_M_disjunction' requested here
 this->_M_disjunction();
 ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/regex_compiler.h:155:14: note: in instantiation of member function 'std::__detail::_Compiler<std::regex_traits<char32_t> >::_Compiler' requested here
 return _Cmplr(__first, __last, __traits, __flags)._M_get_nfa();
 ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/regex.h:524:27: note: in instantiation of function template specialization 'std::__detail::__compile_nfa<std::regex_traits<char32_t> >' requested here
 _M_automaton(__detail::__compile_nfa(_M_original_str.c_str(),
 ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/regex.h:452:9: note: in instantiation of function template specialization 'std::basic_regex<char32_t, std::regex_traits<char32_t=""> >::basic_regex<const char32_t="" *="">' requested here
 : basic_regex(__p, __p + _Rx_traits::length(__p), __f)
 ^
regexp.cpp:10:29: note: in instantiation of member function 'std::basic_regex<char32_t, std::regex_traits<char32_t=""> >::basic_regex' requested here
 std::basic_regex<char32_t> color_regex(U"#([a-f0-9]{2})([a-f0-9]{2})([a-f0-9]{2})");
 ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.9/../../../../include/c++/4.9/bits/regex_compiler.h:413:22: note: shift count 32 >= width of type 'int' (32 bits)
 std::bitset<1 << (8 * sizeof(_CharT))>,
 ^
...
...
...
...
</char32_t></char32_t,></const></char32_t,></std::regex_traits<char32_t></std::regex_traits<char32_t></std::regex_traits<char32_t></std::regex_traits<char32_t></std::regex_traits<char32_t></std::regex_traits<char32_t></false,></false,></std::regex_traits<char32_t></std::regex_traits<char32_t>

Попросите кого-нибудь попробовать?

$ clang --version
Ubuntu clang version 3.4-1ubuntu3 (tags/RELEASE_34/final) (based on LLVM 3.4)
Target: x86_64-pc-linux-gnu
Thread model: posix

$ g++ --version
g++ (Ubuntu 4.9.1-3ubuntu2~14.04.1) 4.9.1
1 ответ

Согласно этой ссылке

Две специализации std::regex_traits определяются стандартной библиотекой:

std::regex_traits<char>
std::regex_traits</char>

Эти специализации позволяют использовать std::basic_regex (aka std::regex) и std::basic_regex (aka std::wregex), но для использования, например, std::basic_regex, необходимо std::regex_traits предоставленную пользователем std::regex_traits.

std::regex_traits не предоставляется стандартом. Вы должны реализовать его самостоятельно, чтобы использовать std::basic_regex.

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