IterStateWrapper< ST, T > Class Template Reference

#include "lib/iter-adapter.hpp"

Description

template<class ST, typename T = iter::CoreYield<ST>>
class lib::IterStateWrapper< ST, T >

Another Lumiera Forward Iterator building block, based on incorporating a state type as »*State Core*«, right into the iterator.

Contrast this to IterAdapter, which refers to a managing container behind the scenes. To the contrary, here all of the state is assumed to live in the custom type embedded into this iterator, accessed and manipulated through a dedicated iteration control API exposed as member functions.

Requirements for a »State Core«

When building iterators with the help of IterStateWrapper or IterableAdapter, it is assumed that the adapted state core type represents a process of state evolution, which reaches a well defined end state eventually, but this end state is also the bottom

• the core is default constructible
• this default state represents the bottom (final, invalid) state.
• copyable, because iterators are passed by value; ideally also assignable
• this type needs to provide an iteration control API with the following operations
  1. checkPoint establishes if the given state element represents a valid active state
  2. iterNext evolves this state by one step (sideeffect)
  3. yield realises the given state, yielding an element of result type T

     Template Parameters

     ST	type of the »state core«, defaults to T. The resulting iterator will hold an instance of ST, which thus needs to be copyable and default constructible to the extent this is required for the iterator as such.
     T	(optional) result type, usually deduced from ST::yield

     See also

     IterableDecorator for variation of the same concept

     iter-explorer-test.hpp

     iter-adaptor-test.cpp

Definition at line 373 of file iter-adapter.hpp.

Public Types
using	pointer = typename meta::RefTraits< T >::Pointer
using	reference = typename meta::RefTraits< T >::Reference
using	value_type = typename meta::RefTraits< T >::Value

Public Member Functions
	IterStateWrapper (ST &&initialState)
	IterStateWrapper (ST const &initialState)
bool	empty () const
	ENABLE_USE_IN_STD_RANGE_FOR_LOOPS (IterStateWrapper)
bool	isValid () const
	operator bool () const
T	operator* () const
IterStateWrapper &	operator++ ()
pointer	operator-> () const

Friends
template<class STX , class T1 , class T2 >
bool	operator== (IterStateWrapper< STX, T1 > const &, IterStateWrapper< STX, T2 > const &)
	comparison is allowed to access state implementation core

Protected Member Functions
void	__throw_if_empty () const
ST &	stateCore ()
	allow derived classes to access state representation
ST const &	stateCore () const

Private Attributes
ST	core_

Inheritance diagram for IterStateWrapper< ST, T >:

Collaboration diagram for IterStateWrapper< ST, T >:

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The documentation for this class was generated from the following file:

• iter-adapter.hpp