boost::regex_match should delete the rvalue reference overload

[supernun]

https://github.com/boostorg/regex/blob/develop/include/boost/regex/v5/regex_match.hpp#L65

The const-ref overload gets picked up in this code-snippet:

std::string GetStr();

boost::smatch m;
if (boost::regex_match(GetStr(), m, boost::regex{"f(o)o"}) {
    m.str(1);  // dangling reference
}

Issue sneaks up on you when GetStr used to return a const std::string & but now returns it by value.

Notably: the std::regex implementation deletes the rvalue reference overload: https://en.cppreference.com/w/cpp/regex/regex_match.html

Boost should probably do the same here.

BOOST_REGEX_MODULE_EXPORT template <class ST, class SA, class Allocator, class charT, class traits>
inline bool regex_match(std::basic_string<charT, ST, SA>&&, 
                 match_results<typename std::basic_string<charT, ST, SA>::const_iterator, Allocator>& m, 
                 const basic_regex<charT, traits>& e, 
                 match_flag_type flags = match_default) = delete;