- tmp/tmp76h21xbj/{from.md → to.md} +30 -416
tmp/tmp76h21xbj/{from.md → to.md}
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## Execution policies <a id="execpol">[[execpol]]</a>
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### In general <a id="execpol.general">[[execpol.general]]</a>
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object of an execution policy type indicates the kinds of
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allowed in the execution of an algorithm and expresses the
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requirements on the element access functions.
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[*Example 1*:
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``` cpp
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using namespace std;
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class parallel_policy;
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// [execpol.parunseq], parallel and unsequenced execution policy
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class parallel_unsequenced_policy;
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// [execpol.objects], execution policy objects
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inline constexpr sequenced_policy seq{ unspecified };
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inline constexpr parallel_policy par{ unspecified };
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inline constexpr parallel_unsequenced_policy par_unseq{ unspecified };
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}
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```
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### Execution policy type trait <a id="execpol.type">[[execpol.type]]</a>
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`is_execution_policy` can be used to detect execution policies for the
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purpose of excluding function signatures from otherwise ambiguous
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overload resolution participation.
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`is_execution_policy<T>`
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characteristic of `true_type` if `T` is the type of a standard or
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*implementation-defined* execution policy, otherwise `false_type`.
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[*Note 1*: This provision reserves the privilege of creating
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non-standard execution policies to the library
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as a unique type to disambiguate parallel algorithm overloading and
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require that a parallel algorithm’s execution may not be parallelized.
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During the execution of a parallel algorithm with the
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`execution::sequenced_policy` policy, if the invocation of an element
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access function exits via an uncaught exception, `terminate()`
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called.
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### Parallel execution policy <a id="execpol.par">[[execpol.par]]</a>
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``` cpp
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as a unique type to disambiguate parallel algorithm overloading and
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indicate that a parallel algorithm’s execution may be parallelized.
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During the execution of a parallel algorithm with the
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`execution::parallel_policy` policy, if the invocation of an element
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access function exits via an uncaught exception, `terminate()`
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called.
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### Parallel and unsequenced execution policy <a id="execpol.parunseq">[[execpol.parunseq]]</a>
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``` cpp
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parallelized and vectorized.
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During the execution of a parallel algorithm with the
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`execution::parallel_unsequenced_policy` policy, if the invocation of an
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element access function exits via an uncaught exception, `terminate()`
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### Execution policy objects <a id="execpol.objects">[[execpol.objects]]</a>
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``` cpp
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inline constexpr execution::sequenced_policy execution::seq{ unspecified };
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inline constexpr execution::parallel_policy execution::par{ unspecified };
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inline constexpr execution::parallel_unsequenced_policy execution::par_unseq{ unspecified };
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```
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The header `<execution>` declares global objects associated with each
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type of execution policy.
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<!-- Link reference definitions -->
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[alg.sorting]: algorithms.md#alg.sorting
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[algorithms]: algorithms.md#algorithms
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[algorithms.general]: algorithms.md#algorithms.general
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[allocator.adaptor]: #allocator.adaptor
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[allocator.adaptor.cnstr]: #allocator.adaptor.cnstr
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[allocator.adaptor.members]: #allocator.adaptor.members
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[allocator.adaptor.types]: #allocator.adaptor.types
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[allocator.globals]: #allocator.globals
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[allocator.members]: #allocator.members
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[allocator.requirements]: library.md#allocator.requirements
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[allocator.requirements.completeness]: library.md#allocator.requirements.completeness
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[allocator.tag]: #allocator.tag
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[allocator.traits]: #allocator.traits
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[allocator.traits.members]: #allocator.traits.members
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[allocator.traits.types]: #allocator.traits.types
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[allocator.uses]: #allocator.uses
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[allocator.uses.construction]: #allocator.uses.construction
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[any]: #any
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[any.class]: #any.class
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[any.cons]: #any.cons
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[any.modifiers]: #any.modifiers
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[any.nonmembers]: #any.nonmembers
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[any.observers]: #any.observers
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[any.synop]: #any.synop
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[arithmetic.operations]: #arithmetic.operations
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[arithmetic.operations.divides]: #arithmetic.operations.divides
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[arithmetic.operations.minus]: #arithmetic.operations.minus
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[arithmetic.operations.modulus]: #arithmetic.operations.modulus
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[arithmetic.operations.multiplies]: #arithmetic.operations.multiplies
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[arithmetic.operations.negate]: #arithmetic.operations.negate
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[arithmetic.operations.plus]: #arithmetic.operations.plus
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[array]: containers.md#array
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[associative]: containers.md#associative
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[atomics.order]: atomics.md#atomics.order
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[atomics.types.operations]: atomics.md#atomics.types.operations
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[basic.align]: basic.md#basic.align
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[basic.compound]: basic.md#basic.compound
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[basic.def.odr]: basic.md#basic.def.odr
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[basic.fundamental]: basic.md#basic.fundamental
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[basic.life]: basic.md#basic.life
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[basic.stc.dynamic.deallocation]: basic.md#basic.stc.dynamic.deallocation
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[basic.stc.dynamic.safety]: basic.md#basic.stc.dynamic.safety
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[basic.types]: basic.md#basic.types
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[bitmask.types]: library.md#bitmask.types
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[bitset]: #bitset
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[bitset.cons]: #bitset.cons
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[bitset.hash]: #bitset.hash
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[bitset.members]: #bitset.members
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[bitset.operators]: #bitset.operators
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[bitset.syn]: #bitset.syn
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[bitwise.operations]: #bitwise.operations
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[bitwise.operations.and]: #bitwise.operations.and
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[bitwise.operations.not]: #bitwise.operations.not
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[bitwise.operations.xor]: #bitwise.operations.xor
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[comparisons]: #comparisons
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[comparisons.less_equal]: #comparisons.less_equal
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[comparisons.not_equal_to]: #comparisons.not_equal_to
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[conv.array]: conv.md#conv.array
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[conv.func]: conv.md#conv.func
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[conv.lval]: conv.md#conv.lval
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[conv.rank]: conv.md#conv.rank
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[csignal.syn]: language.md#csignal.syn
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[cstdlib.syn]: language.md#cstdlib.syn
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[ctime.syn]: #ctime.syn
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[dcl.array]: dcl.md#dcl.array
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[dcl.constexpr]: dcl.md#dcl.constexpr
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[dcl.ref]: dcl.md#dcl.ref
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[declval]: #declval
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[default.allocator]: #default.allocator
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[defns.const.subexpr]: library.md#defns.const.subexpr
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[defns.referenceable]: library.md#defns.referenceable
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[execpol]: #execpol
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[execpol.general]: #execpol.general
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[execpol.objects]: #execpol.objects
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[execpol.par]: #execpol.par
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[execpol.parunseq]: #execpol.parunseq
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[execpol.seq]: #execpol.seq
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[execpol.type]: #execpol.type
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[execution.syn]: #execution.syn
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[expr]: expr.md#expr
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[expr.xor]: expr.md#expr.xor
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[forward]: #forward
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[forward.iterators]: iterators.md#forward.iterators
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[func.bind.bind]: #func.bind.bind
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[func.wrap]: #func.wrap
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[function.objects]: #function.objects
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[functional.syn]: #functional.syn
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[hash.requirements]: library.md#hash.requirements
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[input.iterators]: iterators.md#input.iterators
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[intro.multithread]: intro.md#intro.multithread
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[intseq]: #intseq
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[intseq.general]: #intseq.general
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[intseq.intseq]: #intseq.intseq
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[intseq.make]: #intseq.make
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[invalid.argument]: diagnostics.md#invalid.argument
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[iostate.flags]: input.md#iostate.flags
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[istream.formatted]: input.md#istream.formatted
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[locale.codecvt]: localization.md#locale.codecvt
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[mem.res.monotonic.buffer.mem]: #mem.res.monotonic.buffer.mem
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[mem.res.pool.ctor]: #mem.res.pool.ctor
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[memory]: #memory
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[memory.general]: #memory.general
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[meta]: #meta
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[meta.logical]: #meta.logical
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[meta.trans.cv]: #meta.trans.cv
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[meta.trans.ptr]: #meta.trans.ptr
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[meta.trans.ref]: #meta.trans.ref
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[meta.trans.sign]: #meta.trans.sign
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[meta.type.synop]: #meta.type.synop
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[meta.unary.prop.query]: #meta.unary.prop.query
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[multibyte.strings]: library.md#multibyte.strings
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[namespace.std]: library.md#namespace.std
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[new.delete]: language.md#new.delete
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[nullablepointer.requirements]: library.md#nullablepointer.requirements
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[numeric.requirements]: numerics.md#numeric.requirements
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[operators]: #operators
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[optional]: #optional
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[optional.assign]: #optional.assign
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[optional.bad.access]: #optional.bad.access
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[optional.comp_with_t]: #optional.comp_with_t
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[optional.ctor]: #optional.ctor
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[optional.dtor]: #optional.dtor
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[optional.general]: #optional.general
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[optional.hash]: #optional.hash
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[optional.mod]: #optional.mod
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[optional.nullops]: #optional.nullops
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[optional.nullopt]: #optional.nullopt
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[optional.observe]: #optional.observe
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[optional.optional]: #optional.optional
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[optional.relops]: #optional.relops
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[optional.specalg]: #optional.specalg
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[optional.swap]: #optional.swap
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[optional.syn]: #optional.syn
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[ostream.formatted]: input.md#ostream.formatted
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[out.of.range]: diagnostics.md#out.of.range
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[over.match.call]: over.md#over.match.call
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[over.match.class.deduct]: over.md#over.match.class.deduct
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[overflow.error]: diagnostics.md#overflow.error
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[pair.piecewise]: #pair.piecewise
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[pairs]: #pairs
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[pairs.general]: #pairs.general
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[pairs.spec]: #pairs.spec
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[pointer.traits]: #pointer.traits
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[pointer.traits.functions]: #pointer.traits.functions
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[pointer.traits.types]: #pointer.traits.types
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[ptr.align]: #ptr.align
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[ratio]: #ratio
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[ratio.arithmetic]: #ratio.arithmetic
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[ratio.comparison]: #ratio.comparison
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[ratio.general]: #ratio.general
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[ratio.ratio]: #ratio.ratio
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[ratio.si]: #ratio.si
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[ratio.syn]: #ratio.syn
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[refwrap]: #refwrap
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[refwrap.access]: #refwrap.access
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[refwrap.assign]: #refwrap.assign
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[refwrap.const]: #refwrap.const
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[refwrap.helpers]: #refwrap.helpers
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[refwrap.invoke]: #refwrap.invoke
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[res.on.data.races]: library.md#res.on.data.races
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| 379 |
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[scoped.adaptor.operators]: #scoped.adaptor.operators
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| 380 |
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[smartptr]: #smartptr
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[special]: special.md#special
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[specialized.addressof]: #specialized.addressof
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[specialized.algorithms]: #specialized.algorithms
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| 384 |
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[specialized.destroy]: #specialized.destroy
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| 385 |
-
[stmt.dcl]: stmt.md#stmt.dcl
|
| 386 |
-
[string.classes]: strings.md#string.classes
|
| 387 |
-
[support.dynamic]: language.md#support.dynamic
|
| 388 |
-
[swappable.requirements]: library.md#swappable.requirements
|
| 389 |
-
[tab:copyassignable]: #tab:copyassignable
|
| 390 |
-
[tab:copyconstructible]: #tab:copyconstructible
|
| 391 |
-
[tab:defaultconstructible]: #tab:defaultconstructible
|
| 392 |
-
[tab:destructible]: #tab:destructible
|
| 393 |
-
[tab:equalitycomparable]: #tab:equalitycomparable
|
| 394 |
-
[tab:lessthancomparable]: #tab:lessthancomparable
|
| 395 |
-
[tab:moveassignable]: #tab:moveassignable
|
| 396 |
-
[tab:moveconstructible]: #tab:moveconstructible
|
| 397 |
-
[tab:optional.assign.copy]: #tab:optional.assign.copy
|
| 398 |
-
[tab:optional.assign.copy.templ]: #tab:optional.assign.copy.templ
|
| 399 |
-
[tab:optional.assign.move]: #tab:optional.assign.move
|
| 400 |
-
[tab:optional.assign.move.templ]: #tab:optional.assign.move.templ
|
| 401 |
-
[tab:optional.swap]: #tab:optional.swap
|
| 402 |
-
[tab:ratio.arithmetic]: #tab:ratio.arithmetic
|
| 403 |
-
[tab:time.clock]: #tab:time.clock
|
| 404 |
-
[tab:util.lib.summary]: #tab:util.lib.summary
|
| 405 |
-
[temp.deduct]: temp.md#temp.deduct
|
| 406 |
-
[template.bitset]: #template.bitset
|
| 407 |
-
[time]: #time
|
| 408 |
-
[time.clock]: #time.clock
|
| 409 |
-
[time.clock.hires]: #time.clock.hires
|
| 410 |
-
[time.clock.req]: #time.clock.req
|
| 411 |
-
[time.clock.steady]: #time.clock.steady
|
| 412 |
-
[time.clock.system]: #time.clock.system
|
| 413 |
-
[time.duration]: #time.duration
|
| 414 |
-
[time.duration.alg]: #time.duration.alg
|
| 415 |
-
[time.duration.arithmetic]: #time.duration.arithmetic
|
| 416 |
-
[time.duration.cast]: #time.duration.cast
|
| 417 |
-
[time.duration.comparisons]: #time.duration.comparisons
|
| 418 |
-
[time.duration.cons]: #time.duration.cons
|
| 419 |
-
[time.duration.literals]: #time.duration.literals
|
| 420 |
-
[time.duration.nonmember]: #time.duration.nonmember
|
| 421 |
-
[time.duration.observer]: #time.duration.observer
|
| 422 |
-
[time.duration.special]: #time.duration.special
|
| 423 |
-
[time.general]: #time.general
|
| 424 |
-
[time.point]: #time.point
|
| 425 |
-
[time.point.arithmetic]: #time.point.arithmetic
|
| 426 |
-
[time.point.cast]: #time.point.cast
|
| 427 |
-
[time.point.comparisons]: #time.point.comparisons
|
| 428 |
-
[time.point.cons]: #time.point.cons
|
| 429 |
-
[time.point.nonmember]: #time.point.nonmember
|
| 430 |
-
[time.point.observer]: #time.point.observer
|
| 431 |
-
[time.point.special]: #time.point.special
|
| 432 |
-
[time.syn]: #time.syn
|
| 433 |
-
[time.traits]: #time.traits
|
| 434 |
-
[time.traits.duration_values]: #time.traits.duration_values
|
| 435 |
-
[time.traits.is_fp]: #time.traits.is_fp
|
| 436 |
-
[time.traits.specializations]: #time.traits.specializations
|
| 437 |
-
[tuple]: #tuple
|
| 438 |
-
[tuple.apply]: #tuple.apply
|
| 439 |
-
[tuple.assign]: #tuple.assign
|
| 440 |
-
[tuple.cnstr]: #tuple.cnstr
|
| 441 |
-
[tuple.creation]: #tuple.creation
|
| 442 |
-
[tuple.elem]: #tuple.elem
|
| 443 |
-
[tuple.general]: #tuple.general
|
| 444 |
-
[tuple.helper]: #tuple.helper
|
| 445 |
-
[tuple.rel]: #tuple.rel
|
| 446 |
-
[tuple.special]: #tuple.special
|
| 447 |
-
[tuple.swap]: #tuple.swap
|
| 448 |
-
[tuple.syn]: #tuple.syn
|
| 449 |
-
[tuple.traits]: #tuple.traits
|
| 450 |
-
[tuple.tuple]: #tuple.tuple
|
| 451 |
-
[type.index]: #type.index
|
| 452 |
-
[type.index.hash]: #type.index.hash
|
| 453 |
-
[type.index.members]: #type.index.members
|
| 454 |
-
[type.index.overview]: #type.index.overview
|
| 455 |
-
[type.index.synopsis]: #type.index.synopsis
|
| 456 |
-
[uninitialized.construct.default]: #uninitialized.construct.default
|
| 457 |
-
[uninitialized.construct.value]: #uninitialized.construct.value
|
| 458 |
-
[uninitialized.copy]: #uninitialized.copy
|
| 459 |
-
[uninitialized.fill]: #uninitialized.fill
|
| 460 |
-
[uninitialized.move]: #uninitialized.move
|
| 461 |
-
[unique.ptr]: #unique.ptr
|
| 462 |
-
[unique.ptr.create]: #unique.ptr.create
|
| 463 |
-
[unique.ptr.dltr]: #unique.ptr.dltr
|
| 464 |
-
[unique.ptr.dltr.dflt]: #unique.ptr.dltr.dflt
|
| 465 |
-
[unique.ptr.dltr.dflt1]: #unique.ptr.dltr.dflt1
|
| 466 |
-
[unique.ptr.dltr.general]: #unique.ptr.dltr.general
|
| 467 |
-
[unique.ptr.runtime]: #unique.ptr.runtime
|
| 468 |
-
[unique.ptr.runtime.asgn]: #unique.ptr.runtime.asgn
|
| 469 |
-
[unique.ptr.runtime.ctor]: #unique.ptr.runtime.ctor
|
| 470 |
-
[unique.ptr.runtime.modifiers]: #unique.ptr.runtime.modifiers
|
| 471 |
-
[unique.ptr.runtime.observers]: #unique.ptr.runtime.observers
|
| 472 |
-
[unique.ptr.single]: #unique.ptr.single
|
| 473 |
-
[unique.ptr.single.asgn]: #unique.ptr.single.asgn
|
| 474 |
-
[unique.ptr.single.ctor]: #unique.ptr.single.ctor
|
| 475 |
-
[unique.ptr.single.dtor]: #unique.ptr.single.dtor
|
| 476 |
-
[unique.ptr.single.modifiers]: #unique.ptr.single.modifiers
|
| 477 |
-
[unique.ptr.single.observers]: #unique.ptr.single.observers
|
| 478 |
-
[unique.ptr.special]: #unique.ptr.special
|
| 479 |
-
[unord]: containers.md#unord
|
| 480 |
-
[unord.hash]: #unord.hash
|
| 481 |
-
[util.dynamic.safety]: #util.dynamic.safety
|
| 482 |
-
[util.smartptr]: #util.smartptr
|
| 483 |
-
[util.smartptr.enab]: #util.smartptr.enab
|
| 484 |
-
[util.smartptr.getdeleter]: #util.smartptr.getdeleter
|
| 485 |
-
[util.smartptr.hash]: #util.smartptr.hash
|
| 486 |
-
[util.smartptr.ownerless]: #util.smartptr.ownerless
|
| 487 |
-
[util.smartptr.shared]: #util.smartptr.shared
|
| 488 |
-
[util.smartptr.shared.assign]: #util.smartptr.shared.assign
|
| 489 |
-
[util.smartptr.shared.atomic]: #util.smartptr.shared.atomic
|
| 490 |
-
[util.smartptr.shared.cast]: #util.smartptr.shared.cast
|
| 491 |
-
[util.smartptr.shared.cmp]: #util.smartptr.shared.cmp
|
| 492 |
-
[util.smartptr.shared.const]: #util.smartptr.shared.const
|
| 493 |
-
[util.smartptr.shared.create]: #util.smartptr.shared.create
|
| 494 |
-
[util.smartptr.shared.dest]: #util.smartptr.shared.dest
|
| 495 |
-
[util.smartptr.shared.io]: #util.smartptr.shared.io
|
| 496 |
-
[util.smartptr.shared.mod]: #util.smartptr.shared.mod
|
| 497 |
-
[util.smartptr.shared.obs]: #util.smartptr.shared.obs
|
| 498 |
-
[util.smartptr.shared.spec]: #util.smartptr.shared.spec
|
| 499 |
-
[util.smartptr.weak]: #util.smartptr.weak
|
| 500 |
-
[util.smartptr.weak.assign]: #util.smartptr.weak.assign
|
| 501 |
-
[util.smartptr.weak.bad]: #util.smartptr.weak.bad
|
| 502 |
-
[util.smartptr.weak.const]: #util.smartptr.weak.const
|
| 503 |
-
[util.smartptr.weak.dest]: #util.smartptr.weak.dest
|
| 504 |
-
[util.smartptr.weak.mod]: #util.smartptr.weak.mod
|
| 505 |
-
[util.smartptr.weak.obs]: #util.smartptr.weak.obs
|
| 506 |
-
[util.smartptr.weak.spec]: #util.smartptr.weak.spec
|
| 507 |
-
[utilities]: #utilities
|
| 508 |
-
[utilities.general]: #utilities.general
|
| 509 |
-
[utility]: #utility
|
| 510 |
-
[utility.as_const]: #utility.as_const
|
| 511 |
-
[utility.exchange]: #utility.exchange
|
| 512 |
-
[utility.from.chars]: #utility.from.chars
|
| 513 |
-
[utility.swap]: #utility.swap
|
| 514 |
-
[utility.syn]: #utility.syn
|
| 515 |
-
[utility.to.chars]: #utility.to.chars
|
| 516 |
-
[variant]: #variant
|
| 517 |
-
[variant.assign]: #variant.assign
|
| 518 |
-
[variant.bad.access]: #variant.bad.access
|
| 519 |
-
[variant.ctor]: #variant.ctor
|
| 520 |
-
[variant.dtor]: #variant.dtor
|
| 521 |
-
[variant.general]: #variant.general
|
| 522 |
-
[variant.get]: #variant.get
|
| 523 |
-
[variant.hash]: #variant.hash
|
| 524 |
-
[variant.helper]: #variant.helper
|
| 525 |
-
[variant.mod]: #variant.mod
|
| 526 |
-
[variant.monostate]: #variant.monostate
|
| 527 |
-
[variant.monostate.relops]: #variant.monostate.relops
|
| 528 |
-
[variant.relops]: #variant.relops
|
| 529 |
-
[variant.specalg]: #variant.specalg
|
| 530 |
-
[variant.status]: #variant.status
|
| 531 |
-
[variant.swap]: #variant.swap
|
| 532 |
-
[variant.syn]: #variant.syn
|
| 533 |
-
[variant.traits]: #variant.traits
|
| 534 |
-
[variant.variant]: #variant.variant
|
| 535 |
-
[variant.visit]: #variant.visit
|
| 536 |
-
|
| 537 |
-
[^1]: `pointer_safety::preferred` might be returned to indicate that a
|
| 538 |
-
leak detector is running so that the program can avoid spurious leak
|
| 539 |
-
reports.
|
| 540 |
-
|
| 541 |
-
[^2]: Such a type is a function pointer or a class type which has a
|
| 542 |
-
member `operator()` or a class type which has a conversion to a
|
| 543 |
-
pointer to function.
|
| 544 |
-
|
| 545 |
-
[^3]: `strftime` supports the C conversion specifiers `C`, `D`, `e`,
|
| 546 |
-
`F`, `g`, `G`, `h`, `r`, `R`, `t`, `T`, `u`, `V`, and `z`, and the
|
| 547 |
-
modifiers `E` and `O`.
|
|
|
|
| 1 |
## Execution policies <a id="execpol">[[execpol]]</a>
|
| 2 |
|
| 3 |
### In general <a id="execpol.general">[[execpol.general]]</a>
|
| 4 |
|
| 5 |
+
Subclause [[execpol]] describes classes that are *execution policy*
|
| 6 |
+
types. An object of an execution policy type indicates the kinds of
|
| 7 |
+
parallelism allowed in the execution of an algorithm and expresses the
|
| 8 |
+
consequent requirements on the element access functions.
|
| 9 |
|
| 10 |
[*Example 1*:
|
| 11 |
|
| 12 |
``` cpp
|
| 13 |
using namespace std;
|
|
|
|
| 50 |
class parallel_policy;
|
| 51 |
|
| 52 |
// [execpol.parunseq], parallel and unsequenced execution policy
|
| 53 |
class parallel_unsequenced_policy;
|
| 54 |
|
| 55 |
+
// [execpol.unseq], unsequenced execution policy
|
| 56 |
+
class unsequenced_policy;
|
| 57 |
+
|
| 58 |
// [execpol.objects], execution policy objects
|
| 59 |
inline constexpr sequenced_policy seq{ unspecified };
|
| 60 |
inline constexpr parallel_policy par{ unspecified };
|
| 61 |
inline constexpr parallel_unsequenced_policy par_unseq{ unspecified };
|
| 62 |
+
inline constexpr unsequenced_policy unseq{ unspecified };
|
| 63 |
}
|
| 64 |
```
|
| 65 |
|
| 66 |
### Execution policy type trait <a id="execpol.type">[[execpol.type]]</a>
|
| 67 |
|
|
|
|
| 71 |
|
| 72 |
`is_execution_policy` can be used to detect execution policies for the
|
| 73 |
purpose of excluding function signatures from otherwise ambiguous
|
| 74 |
overload resolution participation.
|
| 75 |
|
| 76 |
+
`is_execution_policy<T>` is a *Cpp17UnaryTypeTrait* with a base
|
| 77 |
characteristic of `true_type` if `T` is the type of a standard or
|
| 78 |
*implementation-defined* execution policy, otherwise `false_type`.
|
| 79 |
|
| 80 |
[*Note 1*: This provision reserves the privilege of creating
|
| 81 |
non-standard execution policies to the library
|
|
|
|
| 94 |
as a unique type to disambiguate parallel algorithm overloading and
|
| 95 |
require that a parallel algorithm’s execution may not be parallelized.
|
| 96 |
|
| 97 |
During the execution of a parallel algorithm with the
|
| 98 |
`execution::sequenced_policy` policy, if the invocation of an element
|
| 99 |
+
access function exits via an uncaught exception, `terminate()` is
|
| 100 |
called.
|
| 101 |
|
| 102 |
### Parallel execution policy <a id="execpol.par">[[execpol.par]]</a>
|
| 103 |
|
| 104 |
``` cpp
|
|
|
|
| 109 |
as a unique type to disambiguate parallel algorithm overloading and
|
| 110 |
indicate that a parallel algorithm’s execution may be parallelized.
|
| 111 |
|
| 112 |
During the execution of a parallel algorithm with the
|
| 113 |
`execution::parallel_policy` policy, if the invocation of an element
|
| 114 |
+
access function exits via an uncaught exception, `terminate()` is
|
| 115 |
called.
|
| 116 |
|
| 117 |
### Parallel and unsequenced execution policy <a id="execpol.parunseq">[[execpol.parunseq]]</a>
|
| 118 |
|
| 119 |
``` cpp
|
|
|
|
| 126 |
parallelized and vectorized.
|
| 127 |
|
| 128 |
During the execution of a parallel algorithm with the
|
| 129 |
`execution::parallel_unsequenced_policy` policy, if the invocation of an
|
| 130 |
element access function exits via an uncaught exception, `terminate()`
|
| 131 |
+
is called.
|
| 132 |
+
|
| 133 |
+
### Unsequenced execution policy <a id="execpol.unseq">[[execpol.unseq]]</a>
|
| 134 |
+
|
| 135 |
+
``` cpp
|
| 136 |
+
class execution::unsequenced_policy { unspecified };
|
| 137 |
+
```
|
| 138 |
+
|
| 139 |
+
The class `unsequenced_policy` is an execution policy type used as a
|
| 140 |
+
unique type to disambiguate parallel algorithm overloading and indicate
|
| 141 |
+
that a parallel algorithm’s execution may be vectorized, e.g., executed
|
| 142 |
+
on a single thread using instructions that operate on multiple data
|
| 143 |
+
items.
|
| 144 |
+
|
| 145 |
+
During the execution of a parallel algorithm with the
|
| 146 |
+
`execution::unsequenced_policy` policy, if the invocation of an element
|
| 147 |
+
access function exits via an uncaught exception, `terminate()` is
|
| 148 |
+
called.
|
| 149 |
|
| 150 |
### Execution policy objects <a id="execpol.objects">[[execpol.objects]]</a>
|
| 151 |
|
| 152 |
``` cpp
|
| 153 |
inline constexpr execution::sequenced_policy execution::seq{ unspecified };
|
| 154 |
inline constexpr execution::parallel_policy execution::par{ unspecified };
|
| 155 |
inline constexpr execution::parallel_unsequenced_policy execution::par_unseq{ unspecified };
|
| 156 |
+
inline constexpr execution::unsequenced_policy execution::unseq{ unspecified };
|
| 157 |
```
|
| 158 |
|
| 159 |
The header `<execution>` declares global objects associated with each
|
| 160 |
type of execution policy.
|
| 161 |
|
|
|
|
|
|
|
|
|
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