SIGFPE ao acessar unordered_map
eu tenho umunordered_map<Block, int>
com o Block sendo uma estrutura simples definida da seguinte forma:
struct Block {
size_t start;
size_t end;
bool operator==(const Block& b) const {
return start == b.start && end == b.end;
}
};
namespace std {
template<>
struct hash<Block> {
size_t operator()(const Block& b) const {
return b.start;
}
};
}
Ao tentar acessar o mapa, recebo a seguinte mensagem de erro no gdb (o mesmo para ambos g ++ 4.7.1 e clang ++ 3.1):
Program received signal SIGFPE, Arithmetic exception.
0x0000000000401e0b in std::__detail::_Mod_range_hashing::operator() (this=0x7fffffffd8e0, __num=0, __den=0)
at /usr/include/c++/4.7/bits/hashtable_policy.h:245
245 { return __num % __den; }
Minha versão do libstdc ++ é 3.4.17 (ou seja, a versão do GCC 4.7)
Backtrace relevante:
#0 0x0000000000401e0b in std::__detail::_Mod_range_hashing::operator() (this=0x7fffffffd8e0, __num=0, __den=0)
at /usr/include/c++/4.7/bits/hashtable_policy.h:245
#1 0x0000000000407199 in std::__detail::_Hash_code_base<Block, std::pair<Block const, int>, std::_Select1st<std::pair<Block const, int> >, std::hash<Block>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::_M_bucket_index (this=0x7fffffffd8e0, __c=0, __n=0) at /usr/include/c++/4.7/bits/hashtable_policy.h:787
#2 0x0000000000405230 in std::_Hashtable<Block, std::pair<Block const, int>, std::allocator<std::pair<Block const, int> >, std::_Select1st<std::pair<Block const, int> >, std::equal_to<Block>, std::hash<Block>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, true, false, true>::_M_bucket_index
(this=0x7fffffffd8e0, __k=..., __c=0) at /usr/include/c++/4.7/bits/hashtable.h:466
#3 0x00000000004038de in std::__detail::_Map_base<Block, std::pair<Block const, int>, std::_Select1st<std::pair<Block const, int> >, true, std::_Hashtable<Block, std::pair<Block const, int>, std::allocator<std::pair<Block const, int> >, std::_Select1st<std::pair<Block const, int> >, std::equal_to<Block>, std::hash<Block>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, true, false, true> >::at (
this=0x7fffffffd8e0, __k=...) at /usr/include/c++/4.7/bits/hashtable_policy.h:474
#4 0x0000000000403001 in SplicedAlignment::FindOptimalEndBlock() const::{lambda(Block const&)#1}::operator()(Block const&) const (__closure=0x7fffffffd990, block=...) at splicing.cpp:151
#5 0x00000000004040b3 in std::for_each<__gnu_cxx::__normal_iterator<Block const*, std::vector<Block, std::allocator<Block> > >, SplicedAlignment::FindOptimalEndBlock() const::{lambda(Block const&)#1}>(__gnu_cxx::__normal_iterator<Block const*, std::vector<Block, std::allocator<Block> > >, SplicedAlignment::FindOptimalEndBlock() const::{lambda(Block const&)#1}, SplicedAlignment::FindOptimalEndBlock() const::{lambda(Block const&)#1}) (__first=..., __last=..., __f=...)
at /usr/include/c++/4.7/bits/stl_algo.h:4442
Edit: Eu não acho que seria realmente fazer a diferençaOnde Eu chamo a função desde que eu apresente os mesmos argumentos, mas parece que sim:
std::for_each(blocks.begin(), blocks.end(), [&](const Block& block) {
map.at(block);
}
leva ao erro, enquanto apenas tendo:
const Block& block = blocks[0];
map.at(block);
funciona perfeitamente bemblocks
sendo um simplesvector<Block>&
)