Boost C++ Libraries: Ticket #13561: boost::detail::nullary_function causes stack overflow when copied

jeff — Wed, 06 Jun 2018 23:36:09 GMT

From the history, it seems the bug in nullary_function has been there for a couple of years. A simple way to fix is to add another overload

      nullary_function(nullary_function& other) BOOST_NOEXCEPT :
      impl(other.impl)
      {
      }

Or to add enable_if to

      template<typename F, typename = typename boost::enable_if<!boost::is_same<typename decay<F>::type, this_type>::value>::type>
      nullary_function(BOOST_THREAD_RV_REF(F) f):
      impl(new impl_type<typename decay<F>::type>(thread_detail::decay_copy(boost::forward<F>(f))))
      {}

jeff — Thu, 07 Jun 2018 02:13:27 GMT

Fix a typo in the second code block: it should be enable_if_c instead of enable_if. also this_type is nullary_function<void()> or nullary_function<R()> (depending on the specialization).

      using this_type = nullary_function<void()>;
      template<typename F, typename = typename boost::enable_if_c<!boost::is_same<typename decay<F>::type, this_type>::value>::type>
      nullary_function(BOOST_THREAD_RV_REF(F) f):
      impl(new impl_type<typename decay<F>::type>(thread_detail::decay_copy(boost::forward<F>(f))))
      {}

owner, status changed

viboes — Tue, 07 Aug 2018 07:01:04 GMT

owner changed from Anthony Williams to viboes
status new → assigned

Thanks for the report. I'll try to fix it soon but a PR on github would help as well.

viboes — Tue, 07 Aug 2018 08:45:58 GMT

I've some trouble identifying where there is recursion

      template<typename F>
      nullary_function(BOOST_THREAD_RV_REF(F) f):
      impl(new impl_type<typename decay<F>::type>(thread_detail::decay_copy(boost::forward<F>(f))))
      {}

impl_type is not nullary_function, isn't it? Could you clarify?

viboes — Tue, 07 Aug 2018 08:50:10 GMT

Oh, I believe I see it now.

The problem is on the open overloads

#ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
      template<typename F>
      explicit nullary_function(F& f);
#endif
      template<typename F>
      nullary_function(BOOST_THREAD_RV_REF(F) f);

milestone changed

viboes — Tue, 07 Aug 2018 12:07:51 GMT

milestone To Be Determined → Boost 1.69

https://github.com/boostorg/thread/commit/d8d549cf3e01fe74779cd421d88d7079c3a25b49

status changed; resolution set

viboes — Tue, 11 Sep 2018 21:32:04 GMT

status assigned → closed
resolution → fixed

Please reopen if you believe the fix is not good enough.