Chapter 18. Parallel Mode (original) (raw)

The libstdc++ parallel mode is an experimental parallel implementation of many algorithms of the C++ Standard Library.

Several of the standard algorithms, for instancestd::sort, are made parallel using OpenMP annotations. These parallel mode constructs can be invoked by explicit source declaration or by compiling existing sources with a specific compiler flag.

Note

The parallel mode has not been kept up to date with recent C++ standards and so it only conforms to the C++03 requirements. That means that move-only predicates may not work with parallel mode algorithms, and for C++20 most of the algorithms cannot be used inconstexpr functions.

For C++17 and above there are new overloads of the standard algorithms which take an execution policy argument. You should consider using those instead of the non-standard parallel mode extensions.

Intro

The following library components in the includenumeric are included in the parallel mode:

std::accumulate
std::adjacent_difference
std::inner_product
std::partial_sum

The following library components in the includealgorithm are included in the parallel mode:

std::adjacent_find
std::count
std::count_if
std::equal
std::find
std::find_if
std::find_first_of
std::for_each
std::generate
std::generate_n
std::lexicographical_compare
std::mismatch
std::search
std::search_n
std::transform
std::replace
std::replace_if
std::max_element
std::merge
std::min_element
std::nth_element
std::partial_sort
std::partition
std::random_shuffle
std::set_union
std::set_intersection
std::set_symmetric_difference
std::set_difference
std::sort
std::stable_sort
std::unique_copy

Chapter 18. Parallel Mode (original) (raw)

Note

Intro

Bibliography