Nema, Ashutosh via llvm-dev
2016-Dec-02 04:54 UTC
[llvm-dev] clang error: static_assert failed "Cache the hash code or make functors involved in hash code and bucket index computation default constructible"
Thanks Brian for pointing out. Yes my libstdc++ doesn't have mentioned fix, after applying it worked !. Regards, Ashutosh From: Brian Cain [mailto:bcain at codeaurora.org] Sent: Thursday, December 1, 2016 7:59 PM To: Nema, Ashutosh <Ashutosh.Nema at amd.com>; cfe-dev at lists.llvm.org Subject: RE: [llvm-dev] clang error: static_assert failed "Cache the hash code or make functors involved in hash code and bucket index computation default constructible" Is it related to this libstdc++ bug? https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56278 Does your libstdc++'s hashtable_policy.h have this change? https://gcc.gnu.org/viewcvs/gcc/trunk/libstdc%2B%2B-v3/include/bits/hashtable_policy.h?r1=195935&r2=195934&pathrev=195935 FWIW this test case works on clang 3.6 and 3.9.0 with the libstdc++ at Godbolt https://godbolt.org/g/beq77a -Brian From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of Nema, Ashutosh via llvm-dev Sent: Thursday, December 1, 2016 12:19 AM To: llvm-dev <llvm-dev at lists.llvm.org<mailto:llvm-dev at lists.llvm.org>>; cfe-dev at lists.llvm.org<mailto:cfe-dev at lists.llvm.org> Subject: [llvm-dev] clang error: static_assert failed "Cache the hash code or make functors involved in hash code and bucket index computation default constructible" Hi, Consider below test case: 1 #include <unordered_map> 2 3 using key=const int; 4 struct Myhash { 5 Myhash() = default; 6 std::hash<int> hash_int_t; 7 inline size_t operator()(const key& x) const throw() { 8 return hash_int_t(x); 9 } 10 }; 11 std::unordered_map<key,int, Myhash> mm; It compile with gcc (version 4.8.4) whereas I'm unable to compile same with clang. Clang fails with below errors: $ clang++ fail.cpp -std=c++11 -O0 -c In file included from fail.cpp:1: In file included from /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/unordered_map:47: /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/bits/hashtable.h:268:7: error: static_assert failed "Cache the hash code or make functors involved in hash code and bucket index computation default constructible" static_assert(__if_hash_not_cached< ^ ~~~~~~~~~~~~~~~~~~~~~ /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/bits/unordered_map.h:120:36: error: member 'iterator' found in multiple base classes of different types typedef typename _Hashtable::iterator iterator; ^ In file included from fail.cpp:1: In file included from /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/unordered_map:48: /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/bits/unordered_map.h:121:36: error: member 'const_iterator' found in multiple base classes of different types typedef typename _Hashtable::const_iterator const_iterator; In file included from fail.cpp:1: In file included from /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/unordered_map:48: /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/bits/unordered_map.h:124:36: error: member 'size_type' found in multiple base classes of different types typedef typename _Hashtable::size_type size_type; ^ In file included from fail.cpp:1: In file included from /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/unordered_map:48: /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/bits/unordered_map.h:452:7: error: multiple overloads of 'erase' instantiate to the same signature 'iterator (iterator)' (aka 'int (int)') erase(iterator __it) ^ Is this a known issue, or something I missed here ? Regards, Ashutosh -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20161202/9e8cc5b4/attachment.html>