C++ named requirements: RandomNumberEngineAdaptor

 

C++

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Named requirements

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Concepts library (C++20)

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Technical Specifications

 

C++ named requirements

Basic
DefaultConstructible CopyAssignable CopyConstructible	MoveAssignable (C++11) MoveConstructible (C++11) Destructible
Layout
TrivialType (C++11) TriviallyCopyable (C++11)	StandardLayoutType (C++11) PODType
Library-Wide
EqualityComparable LessThanComparable Swappable (C++11) ValueSwappable (C++11) NullablePointer (C++11) Hash (C++11)	Allocator FunctionObject Callable Predicate BinaryPredicate Compare
Container
Container SequenceContainer ContiguousContainer (C++17) ReversibleContainer	AssociativeContainer AllocatorAwareContainer UnorderedAssociativeContainer (C++11)
Container Elements
DefaultInsertable (C++11) CopyInsertable (C++11) MoveInsertable (C++11)	EmplaceConstructible (C++11) Erasable (C++11)
Iterator
LegacyIterator LegacyOutputIterator LegacyInputIterator LegacyForwardIterator	LegacyBidirectionalIterator LegacyRandomAccessIterator LegacyContiguousIterator (C++17) ConstexprIterator (C++20)
Stream I/O
FormattedInputFunction UnformattedInputFunction	FormattedOutputFunction UnformattedOutputFunction
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)	Mutex (C++11) TimedMutex (C++11) SharedMutex (C++17) SharedTimedMutex (C++14)
Other
CharTraits RegexTraits (C++11) BitmaskType NumericType LiteralType (C++11)	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)