Hi,
Consider below test case:
1 #include <unordered_map>
2
3 using key=const int;
4 struct Myhash {
5 Myhash() = default;
6 std::hash 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