Deduction guides¶
Where possible, constructors of concurrent_multimap support class template argument
deduction (since C++17):
template <typename InputIterator,
typename Compare = std::less<iterator_key_t<InputIterator>>,
typename Allocator = tbb_allocator<iterator_alloc_value_t<InputIterator>>>
concurrent_multimap( InputIterator, InputIterator, Compare = Compare(), Allocator = Allocator() )
-> concurrent_multimap<iterator_key_t<InputIterator>,
iterator_mapped_t<InputIterator>,
Compare,
Allocator>;
template <typename InputIterator,
typename Allocator>
concurrent_multimap( InputIterator, InputIterator, Allocator )
-> concurrent_multimap<iterator_key_t<InputIterator>,
iterator_mapped_t<InputIterator>,
std::less<iterator_key_t<InputIterator>>,
Allocator>;
template <typename Key,
typename T,
typename Compare = std::less<Key>,
typename Allocator = tbb_allocator<std::pair<const Key, T>>>
concurrent_multimap( std::initializer_list<std::pair<Key, T>>, Compare = Compare(), Allocator = Allocator() )
-> concurrent_multimap<Key, T, Compare, Allocator>;
template <typename Key,
typename T,
typename Allocator>
concurrent_multimap( std::initializer_list<std::pair<Key, T>>, Allocator )
-> concurrent_multimap<Key, T, std::less<Key>, Allocator>;
where the type aliases iterator_key_t, iterator_mapped_t, iterator_alloc_value_t are defined as follows:
template <typename InputIterator>
using iterator_key_t = std::remove_const_t<typename std::iterator_traits<InputIterator>::value_type::first_type>;
template <typename InputIterator>
using iterator_mapped_t = typename std::iterator_traits<InputIterator>::value_type::second_type;
template <typename InputIterator>
using iterator_alloc_value_t = std::pair<std::add_const_t<iterator_key_t<InputIterator>>,
iterator_mapped_t<InputIterator>>;
Example
#include <tbb/concurrent_map.h>
#include <vector>
int main() {
std::vector<std::pair<int, float>> v;
// Deduces cm1 as concurrent_multimap<int, float>
tbb::concurrent_multimap cm1(v.begin(), v.end());
// Deduces cm2 as concurrent_multimap<int, float>
tbb::concurrent_multimap cm2({std::pair(1, 2f), std::pair(2, 3f)});
}