Deduction guides

Where possible, constructors of tbb::concurrent_queue support class template argument deduction (since C++17):

template <typename InputIterator,
          typename Allocator = cache_aligned_allocator<iterator_value_t<InputIterator>>
concurrent_queue( InputIterator, InputIterator, const Allocator& = Allocator() )
-> concurrent_queue<iterator_value_t<InputIterator>, Allocator>;

Where the type alias iterator_value_t is defined as follows:

template <typename InputIterator>
using iterator_value_t = typename std::iterator_traits<InputIterator>::value_type;

Example

#include <tbb/concurrent_queue.h>
#include <vector>
#include <memory>

int main() {
    std::vector<int> vec;

    // Deduces cq1 as tbb::concurrent_queue<int>
    tbb::concurrent_queue cq1(vec.begin(), vec.end());

    // Deduces cq2 as tbb::concurrent_queue<int, std::allocator<int>>
    tbb::concurrent_queue cq2(vec.begin(), vec.end(), std::allocator<int>{})
}