Fix gcc 9 deprecated copy warnings.

[Romain-Geissler-1A]

Hi,

When building with gcc 9, we get some of these new deprecated copy warnings. Explicitly defining the copy constructors silences them.

Cheers,
Romain

[orivej]

It seems that operator=(); is meant to prohibit assignment and should be deleted instead: simple_repeat_matcher &operator =(simple_repeat_matcher const &) = delete;. The same applies to all matchers, and probably to other declarations of operator=(); without definition.

[Romain-Geissler-1A]

@orivej Indeed I made this PR too quickly...

I have updated it. I grepped for all "operator=" calls, and explicitly deleted it if it was a private non implemented one.

[Romain-Geissler-1A]

Ping

[arghness]

I'm having what seem to be related warnings. ( Boost 1.78, gcc 11.2.1 compiling with -Wextra ). I tried applying this pull request but still got warnings with the following code:

#include <boost/xpressive/xpressive_static.hpp>

int
main(int /*argc*/, char * /*argv*/ [])
{
  return 0;
}

In file included from /opt/boost/include/boost/xpressive/xpressive_static.hpp:24,
                 from test.cpp:1:
/opt/boost/include/boost/xpressive/regex_primitives.hpp: In static member function 'static boost::xpressive::detail::basic_mark_tag boost::xpressive::mark_tag::make_tag(int)':
/opt/boost/include/boost/xpressive/regex_primitives.hpp:548:16: warning: implicitly-declared 'constexpr boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::xpressive::detail::mark_placeholder>, 0>::expr(const boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::xpressive::detail::mark_placeholder>, 0>&)' is deprecated [-Wdeprecated-copy]
  548 |         return mark;
      |                ^~~~
In file included from /opt/boost/include/boost/proto/detail/expr.hpp:4,
                 from /opt/boost/include/boost/proto/expr.hpp:145,
                 from /opt/boost/include/boost/proto/core.hpp:17,
                 from /opt/boost/include/boost/xpressive/regex_primitives.hpp:28,
                 from /opt/boost/include/boost/xpressive/xpressive_static.hpp:24,
                 from test.cpp:1:
/opt/boost/include/boost/proto/detail/preprocessed/expr_variadic.hpp:96:9: note: because 'boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::xpressive::detail::mark_placeholder>, 0>' has user-provided 'const boost::proto::exprns_::expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::expr<Tag, boost::proto::argsns_::term<Arg>, 0>&, const boost::proto::exprns_::expr<Tag, boost::proto::argsns_::term<Arg>, 0>&>, 2> boost::proto::exprns_::expr<Tag, boost::proto::argsns_::term<Arg>, 0>::operator=(const boost::proto::exprns_::expr<Tag, boost::proto::argsns_::term<Arg>, 0>&) [with Tag = boost::proto::tagns_::tag::terminal; Arg0 = boost::xpressive::detail::mark_placeholder]'
   96 |         operator =(expr const &a)
      |         ^~~~~~~~
...
...
...

The proto expr::operator=() is actually defined and required. I tried adding a copy constructor, as a test, but that led to another issue where the class is being list initialized and so that wasn't possible with a copy constructor.

I think the only workaround is to disable that warning for now.