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Some build bots have not been updated to the new minimal CMake version.
Reverting for now and ping the buildbot owners.
This reverts commit 44c6b905f8.
Parallel STL
Parallel STL is an implementation of the C++ standard library algorithms with support for execution policies, as specified in ISO/IEC 14882:2017 standard, commonly called C++17. The implementation also supports the unsequenced execution policy specified in Parallelism TS version 2 and proposed for the next version of the C++ standard in the C++ working group paper P1001. Parallel STL offers efficient support for both parallel and vectorized execution of algorithms. For sequential execution, it relies on an available implementation of the C++ standard library.
Prerequisites
To use Parallel STL, you must have the following software installed:
- C++ compiler with:
- Support for C++11
- Support for OpenMP* 4.0 SIMD constructs
- Threading Building Blocks (TBB) which is available for download at https://github.com/01org/tbb/
Known issues and limitations
unseqandpar_unseqpolicies only have effect with compilers that support#pragma omp simdor#pragma simd.- Parallel and vector execution is only supported for the algorithms if random access iterators are provided, while for other iterator types the execution will remain serial.
- The following algorithms do not allow efficient SIMD execution:
includes,inplace_merge,merge,nth_element,partial_sort,partial_sort_copy,set_difference,set_intersection,set_symmetric_difference,set_union,sort,stable_partition,stable_sort,unique. - The initial value type for
exclusive_scan,inclusive_scan,transform_exclusive_scan,transform_inclusive_scanshall be DefaultConstructible. A default constructed-instance of the initial value type shall be the identity element for the specified binary operation. - For
max_element,min_element,minmax_element,partial_sort,partial_sort_copy,sort,stable_sortthe dereferenced value type of the provided iterators shall be DefaultConstructible. - For
remove,remove_if,uniquethe dereferenced value type of the provided iterators shall be MoveConstructible. - The following algorithms require additional O(n) memory space for parallel execution:
copy_if,inplace_merge,partial_sort,partial_sort_copy,partition_copy,remove,remove_if,rotate,sort,stable_sort,unique,unique_copy.