algorithm/string -- find_all_regex() gives a compiler error when the result container is vector<iterator_range<string::iterator>>

まず、std::vector<boost::iterator_rangestd::string::iterator> を使用した、提供されている boost::find_all_regex の呼び出しを再現し、std::vectorstd::string の場合と比較します。リンクされている find_all_regex のドキュメントと関数の実装を読みます。完了の条件は、文書化されているコンテナの不一致を解消するか、ドキュメントを明確に修正し、テストが利用可能な場合は報告された例をカバーすることです。

The doc says that the container we should pass to this function can be std::vector<boost::iterator_rangestd::string::iterator>. But when I run the program it gives a compile error. But when the result container passed, is a std::vectorstd::string, everything works fine.

First code snippet is using std::vector<boost::iterator_rangestd::string::iterator> as the result.

#include "boost/algorithm/string/split.hpp"
#include "boost/range/iterator_range_core.hpp"
#include <iostream>
#include <boost/algorithm/string.hpp>
#include <boost/algorithm/string/regex.hpp>
#include <vector>

int main(int, char**) {
    
    std::string s("Hello world");
    boost::regex regex("\\w");

    std::vector<boost::iterator_range<std::string::iterator>> result;
    boost::find_all_regex(result, s, regex);

}

Following is the last 3 lines of the compiler error. The whole error is too long.

c:\mingw\include\c++\9.2.0\bits\stl_iterator.h:787:11: note: no known conversion for argument 1 from '__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string >' to 'const __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string >&'

c:\mingw\include\c++\9.2.0\bits\stl_iterator.h:787:11: note: candidate: 'constexpr __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string >::__normal_iterator(__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string >&&)'

c:\mingw\include\c++\9.2.0\bits\stl_iterator.h:787:11: note: no known conversion for argument 1 from '__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string >' to '__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string >&&'

Also I ran the same program in Clang compiler too. Still the same result.

But when I run the following program with the container as std::vectorstd::string everything works without a hitch.

#include "boost/algorithm/string/split.hpp"
#include "boost/range/iterator_range_core.hpp"
#include <iostream>
#include <boost/algorithm/string.hpp>
#include <boost/algorithm/string/regex.hpp>
#include <string>
#include <vector>

int main(int, char**) {
    
    std::string s("Hello world");
    boost::regex regex("\\w");

    std::vector<std::string> result;
    boost::find_all_regex(result, s, regex);

}