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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>Is it related to this libstdc++ bug?<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><a href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56278">https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56278</a><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Does your libstdc++’s hashtable_policy.h have this change?<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><a href="https://gcc.gnu.org/viewcvs/gcc/trunk/libstdc%2B%2B-v3/include/bits/hashtable_policy.h?r1=195935&r2=195934&pathrev=195935">https://gcc.gnu.org/viewcvs/gcc/trunk/libstdc%2B%2B-v3/include/bits/hashtable_policy.h?r1=195935&r2=195934&pathrev=195935</a><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>FWIW this test case works on clang 3.6 and 3.9.0 with the libstdc++ at Godbolt https://godbolt.org/g/beq77a<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>-Brian<o:p></o:p></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>From:</b> llvm-dev [mailto:llvm-dev-bounces@lists.llvm.org] <b>On Behalf Of </b>Nema, Ashutosh via llvm-dev<br><b>Sent:</b> Thursday, December 1, 2016 12:19 AM<br><b>To:</b> llvm-dev <llvm-dev@lists.llvm.org>; cfe-dev@lists.llvm.org<br><b>Subject:</b> [llvm-dev] clang error: static_assert failed "Cache the hash code or make functors involved in hash code and bucket index computation default constructible"<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Hi,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Consider below test case:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> 1 #include <unordered_map><o:p></o:p></p><p class=MsoNormal> 2<o:p></o:p></p><p class=MsoNormal> 3 using key=const int;<o:p></o:p></p><p class=MsoNormal> 4 struct Myhash {<o:p></o:p></p><p class=MsoNormal> 5 Myhash() = default;<o:p></o:p></p><p class=MsoNormal> 6 std::hash<int> hash_int_t;<o:p></o:p></p><p class=MsoNormal> 7 inline size_t operator()(const key& x) const throw() {<o:p></o:p></p><p class=MsoNormal> 8 return hash_int_t(x);<o:p></o:p></p><p class=MsoNormal> 9 }<o:p></o:p></p><p class=MsoNormal> 10 };<o:p></o:p></p><p class=MsoNormal> 11 std::unordered_map<key,int, Myhash> mm;<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>It compile with gcc (version 4.8.4) whereas I’m unable to compile same with clang.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Clang fails with below errors:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>$ clang++ fail.cpp -std=c++11 -O0 –c<o:p></o:p></p><p class=MsoNormal><i>In file included from fail.cpp:1:<o:p></o:p></i></p><p class=MsoNormal><i>In file included from /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/unordered_map:47:<o:p></o:p></i></p><p class=MsoNormal><i>/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/bits/hashtable.h:268:7: <b>error</b>: static_assert failed "Cache the hash code or make functors involved in hash code and bucket index computation default constructible"<o:p></o:p></i></p><p class=MsoNormal><i> static_assert(__if_hash_not_cached<<o:p></o:p></i></p><p class=MsoNormal><i> ^ ~~~~~~~~~~~~~~~~~~~~~<o:p></o:p></i></p><p class=MsoNormal><i>/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/bits/unordered_map.h:120:36: <b>error</b>: member 'iterator' found in multiple base classes of different types<o:p></o:p></i></p><p class=MsoNormal><i> typedef typename _Hashtable::iterator iterator;<o:p></o:p></i></p><p class=MsoNormal><i> ^<o:p></o:p></i></p><p class=MsoNormal><i>In file included from fail.cpp:1:<o:p></o:p></i></p><p class=MsoNormal><i>In file included from /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/unordered_map:48:<o:p></o:p></i></p><p class=MsoNormal><i>/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/bits/unordered_map.h:121:36: <b>error</b>: member 'const_iterator' found in multiple base classes of different types<o:p></o:p></i></p><p class=MsoNormal><i> typedef typename _Hashtable::const_iterator const_iterator;<o:p></o:p></i></p><p class=MsoNormal><i><o:p> </o:p></i></p><p class=MsoNormal><i>In file included from fail.cpp:1:<o:p></o:p></i></p><p class=MsoNormal><i>In file included from /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/unordered_map:48:<o:p></o:p></i></p><p class=MsoNormal><i>/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/bits/unordered_map.h:124:36: <b>error</b>: member 'size_type' found in multiple base classes of different types<o:p></o:p></i></p><p class=MsoNormal><i> typedef typename _Hashtable::size_type size_type;<o:p></o:p></i></p><p class=MsoNormal><i> ^<o:p></o:p></i></p><p class=MsoNormal><i><o:p> </o:p></i></p><p class=MsoNormal><i>In file included from fail.cpp:1:<o:p></o:p></i></p><p class=MsoNormal><i>In file included from /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/unordered_map:48:<o:p></o:p></i></p><p class=MsoNormal><i>/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/bits/unordered_map.h:452:7: <b>error</b>: multiple overloads of 'erase' instantiate to the same signature 'iterator (iterator)' (aka 'int (int)')<o:p></o:p></i></p><p class=MsoNormal><i> erase(iterator __it)<o:p></o:p></i></p><p class=MsoNormal><i> ^<o:p></o:p></i></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Is this a known issue, or something I missed here ?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Regards,<o:p></o:p></p><p class=MsoNormal>Ashutosh<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>