C++ named requirements: RandomNumberEngineAdaptor (since C++11)

 

C++

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Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Diagnostics library

Memory management library

Metaprogramming library (C++11)

General utilities library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

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Technical specifications

Symbols index

External libraries

 

C++ named requirements

Basic DefaultConstructible MoveConstructible (C++11) CopyConstructible CopyAssignable MoveAssignable (C++11) Destructible Type properties ScalarType PODType TriviallyCopyable (C++11) TrivialType (C++11) StandardLayoutType (C++11)   ImplicitLifetimeType Library-wide BooleanTestable EqualityComparable LessThanComparable Swappable ValueSwappable (C++11) NullablePointer (C++11) Hash (C++11) Allocator FunctionObject Callable Predicate BinaryPredicate Compare

Container Container ReversibleContainer AllocatorAwareContainer SequenceContainer ContiguousContainer (C++17) AssociativeContainer UnorderedAssociativeContainer (C++11)   Container element DefaultInsertable (C++11) CopyInsertable (C++11) MoveInsertable (C++11) EmplaceConstructible (C++11) Erasable (C++11) Iterator LegacyIterator LegacyInputIterator LegacyOutputIterator LegacyForwardIterator LegacyBidirectionalIterator LegacyRandomAccessIterator LegacyContiguousIterator (C++17) ConstexprIterator (C++20) Stream I/O FormattedInputFunction UnformattedInputFunction FormattedOutputFunction UnformattedOutputFunction Formatters BasicFormatter (C++20) Formatter (C++20)

Random Numbers SeedSequence (C++11) RandomNumberEngine (C++11) RandomNumberDistribution (C++11) UniformRandomBitGenerator (C++11) RandomNumberEngineAdaptor (C++11) Concurrency BasicLockable (C++11) Lockable (C++11) TimedLockable (C++11) SharedLockable (C++14) SharedTimedLockable (C++14) Mutex (C++11) TimedMutex (C++11) SharedMutex (C++17) SharedTimedMutex (C++14) Ranges RangeAdaptorObject (C++20) RangeAdaptorClosureObject (C++20) Multidimensional View LayoutMapping (C++23) LayoutMappingPolicy (C++23) AccessorPolicy (C++23) Other CharTraits RegexTraits (C++11)   BitmaskType LiteralType (C++11) NumericType UnaryTypeTrait (C++11) BinaryTypeTrait (C++11) TransformationTrait (C++11) Clock (C++11) TrivialClock (C++11)

 

A RandomNumberEngineAdaptor is a RandomNumberEngine that transforms the output of another RandomNumberEngine, the latter of which is termed a base engine.

Requirements

Given

• B, a RandomNumberEngine
• b, an object of type B
• A, a RandomNumberEngineAdaptor, adapting B as a base engine
• a, an object of type A

function	semantics
A::A();	The base engine is initialized as if by its default constructor.
bool operator==(const A& lhs, const A& rhs);	Returns whether lhs's base engine is equal to rhs's base engine or not.
A::A(result_type s);	The base engine is initialized with s.
template<class Sseq> A::A(Sseq& q);	The base engine is initialized with q.
void seed();	Invokes b.seed().
void seed(result_type s);	Invokes b.seed(s).
template<class Sseq> void seed(Sseq& q);	Invokes b.seed(q).

Furthermore

• The complexity of each function of A does not exceed the complexity of the function of B
• The state of A includes the state of B
• The size of A's state is no less than the size of b
• Copying A's state includes copying B's state
• The textual representation of A includes the textual representation of B

Standard library

The following standard library facilities satisfy RandomNumberEngineAdaptor:

discard_block_engine (C++11)	discards some output of a random number engine (class template)
independent_bits_engine (C++11)	packs the output of a random number engine into blocks of a specified number of bits (class template)
shuffle_order_engine (C++11)	delivers the output of a random number engine in a different order (class template)