Extensions for parallelism
The C++ Extensions for Parallelism, ISO/IEC TS 19570:2015 defines the following new components for the C++ standard library:
Execution policies
The parallelism TS describes three execution policies: sequential, parallel, and parallel+vector, and provides corresponding execution policy types and objects. Users may select an execution policy statically by invoking a parallel algorithm with the an execution policy object of the corresponding type, or dynamically by using the type-erasing execution_policy class.
Implementations may define additional execution policies as an extension. The semantics of parallel algorithms invoked with an execution policy object of implementation-defined type is implementation-defined.
| Defined in header
<experimental/execution_policy> | |
| execution policy types (class) | |
| global execution policy objects (constant) | |
| dynamic execution policy (class) | |
| test whether a class represents an execution policy (class template) | |
Exception lists
| Defined in header
<experimental/exception_list> | |
| exceptions raised during parallel executions (class) | |
Parallelized versions of existing algorithms
The TS provides parallelized versions of the following 69 algorithms from <algorithm>, <numeric> and <memory>:
New algorithms
| Defined in header
<experimental/algorithm> | |
| similar to std::for_each except returns void (function template) | |
| applies a function object to the first n elements of a sequence (function template) | |
| Defined in header
<experimental/numeric> | |
| (parallelism TS) |
similar to std::accumulate, except out of order (function template) |
| similar to std::partial_sum, excludes the ith input element from the ith sum (function template) | |
| similar to std::partial_sum, includes the ith input element in the ith sum (function template) | |
| (parallelism TS) |
applies a functor, then reduces out of order (function template) |
| applies a functor, then calculates exclusive scan (function template) | |
| applies a functor, then calculates inclusive scan (function template) | |