[Boost-bugs] [Boost C++ Libraries] #12645: error: no match for call to ‘(const hash) (const boost::recursive_variant_&)’

Subject: [Boost-bugs] [Boost C++ Libraries] #12645: error: no match for call to ‘(const hash) (const boost::recursive_variant_&)’
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2016-12-03 11:39:50

#12645: error: no match for call to ‘(const hash) (const
boost::recursive_variant_&)’
------------------------------+------------------------
 Reporter:  mike.gresens@…    |      Owner:  ebf
     Type:  Bugs              |     Status:  new
Milestone:  To Be Determined  |  Component:  variant
  Version:  Boost 1.63.0      |   Severity:  Regression
 Keywords:                    |
------------------------------+------------------------
 Since boost 1.62 the recursive variant is not able to find the hash
 function.[[BR]]
 Same for boost 1.63 beta.[[BR]]
 Compiler stops with error: no match for call to ‘(const hash) (const
 boost::recursive_variant_&)’

 code:
 {{{
 #include <boost/variant.hpp>
 #include <unordered_set>

 struct hash;

 using int_t = int;

 template <typename T>
 using basic_set_t = std::unordered_set<T, hash>;

 using value_t = boost::make_recursive_variant<
                 int_t,
                 basic_set_t<boost::recursive_variant_>
 >::type;

 using set_t = basic_set_t<value_t>;

 struct hash
 {
         // since boost 1.62 ... error: no match for call to ‘(const hash)
 (const boost::recursive_variant_&)’
         size_t operator()(const value_t& value) const
         {
                 return 0;
         }
 };

 int main()
 {
         set_t s;
         int_t i = 3;
         value_t v = i;
         s.emplace(v); // raises error above
         v = s;
         return 0;
 }
 }}}

 gcc 6.2.0 on Linux[[BR]]
 clang 7.0.2 on Mac

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/12645>
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