Deduction guides¶
If possible, concurrent_bounded_queue constructors support class template argument deduction (since C++17).
Copy and move constructors, including constructors with an explicit allocator_type argument,
provide implicitly-generated deduction guides.
In addition, the following explicit deduction guide is provided:
template <typename InputIterator,
typename Allocator = tbb::cache_aligned_allocator<iterator_value_t<InputIterator>>
concurrent_bounded_queue( InputIterator, InputIterator,
Allocator = Allocator() )
-> concurrent_bounded_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;
This deduction guides only participate in the overload resolution if the following requirements are met:
The
InputIteratortype meets theInputIteratorrequirements described in the [input.iterators] section of the ISO C++ Standard.The
Allocatortype meets theAllocatorrequirements described in the [allocator.requirements] section of the ISO C++ Standard.
Example
#include <oneapi/tbb/concurrent_queue.h>
#include <vector>
#include <memory>
int main() {
std::vector<int> vec;
// Deduces cq1 as oneapi::tbb::concurrent_bounded_queue<int>
oneapi::tbb::concurrent_bounded_queue cq1(vec.begin(), vec.end());
// Deduces cq2 as oneapi::tbb::concurrent_bounded_queue<int, std::allocator<int>>
oneapi::tbb::concurrent_bounded_queue cq2(vec.begin(), vec.end(), std::allocator<int>{})
}