Hash support classes to use with associative containers provided by Intel® Threading Building Blocks (Intel® TBB).
template<typename Key> struct tbb_hash_compare; template<typename Key> struct tbb_hash;
A tbb_hash_compare<Key> is the default for the HashCompare argument of template class concurrent_hash_map. A tbb_hash<Key> is the default for the Hasher argument of template classes concurrent_unordered_[multi]map, concurrent_unordered_[multi]set. The built-in definitions rely on operator== and tbb_hasher as shown in the Members description. For your own types, you can define template specializations of tbb_hash_compare or tbb_hash, or define an overload of tbb_hasher.
There are built-in definitions of tbb_hasher for the following Key types:
Types that are convertible to a size_t by static_cast<T>
Pointer types
std::basic_string
std::pair<K1,K2> where K1 and K2 are hashed using tbb_hasher.
namespace tbb {
template<typename T>
size_t tbb_hasher(const T&);
template<typename T>
size_t tbb_hasher(T*);
template<typename T, typename Traits, typename Alloc>
size_t tbb_hasher(const std::basic_string<T, Traits,Alloc>&);
template<typename T1, typename T2>
size_t tbb_hasher(const std::pair<T1,T2>& );
template<typename Key>
struct tbb_hash_compare {
static size_t hash(const Key& k) {
return tbb_hasher(k);
}
static bool equal(const Key& k1, const Key& k2) {
return k1==k2;
}
};
template<typename Key>
struct tbb_hash {
tbb_hash() {}
size_t operator()(const Key& k) const {
return tbb_hasher(k);
}
};
}