ArrayIterator< ArrayType, ValueType > Class Template Reference

Generic iterator class for arrays, allowing use of STL algorithms, range-based for etc. More...

#include <ArrayIterator.h>

Public Types
using	iterator_category = std::forward_iterator_tag
	Iterator category.
using	difference_type = std::ptrdiff_t
	Difference type.
using	value_type = ValueType
	Value type.
using	pointer = ValueType *
	Pointer.
using	reference = ValueType &
	Reference.

Public Member Functions
	ArrayIterator ()
	Default constructor (not that you can dereference these).
	ArrayIterator (const ArrayType *array, int index)
	Constructor.
ArrayIterator< ArrayType, ValueType > &	operator++ ()
	Prefix increment.
ArrayIterator< ArrayType, ValueType >	operator++ (int)
	Postfix increment.
bool	operator== (const ArrayIterator< ArrayType, ValueType > &rhs) const
	Check equality.
bool	operator!= (const ArrayIterator< ArrayType, ValueType > &rhs) const
	Check inequality.
ValueType &	operator* () const
	Dereference.
ValueType *	operator-> () const
	Dereference.

Static Private Member Functions
static ValueType &	deref_if_needed (ValueType &t)
	Dereference if argument is a pointer to ValueType.
static ValueType &	deref_if_needed (ValueType *t)
	Dereference if argument is a pointer to ValueType.

Private Attributes
const ArrayType *	m_array
	Array to iterate over.
int	m_index
	Current index.

Detailed Description

template<class ArrayType, class ValueType>
class Belle2::ArrayIterator< ArrayType, ValueType >

Generic iterator class for arrays, allowing use of STL algorithms, range-based for etc.

Implements all operations required for a forward iterator. Note that wether objects can actually be added (i.e. extending the array) depends on the implementation of operator[].

It only requires that ArrayType provides operator[int] returning pointers or references to ValueType, you can then return ArrayIterator objects * with indices 0 and size() from begin() and end(). You should also define iterator and const_iterator typedefs as part of ArrayType. See StoreArray for examples.

Note that dereferencing an iterator via * returns a reference to ValueType, regardless of wether ArrayType::operator[] returns ValueType* or ValueType&.

Definition at line 102 of file ArrayIterator.h.

Member Typedef Documentation

difference_type

using difference_type = std::ptrdiff_t

Difference type.

Definition at line 110 of file ArrayIterator.h.

iterator_category

using iterator_category = std::forward_iterator_tag

Iterator category.

Definition at line 107 of file ArrayIterator.h.

pointer

using pointer = ValueType*

Pointer.

Definition at line 116 of file ArrayIterator.h.

reference

using reference = ValueType&

Reference.

Definition at line 119 of file ArrayIterator.h.

value_type

using value_type = ValueType

Value type.

Definition at line 113 of file ArrayIterator.h.

Constructor & Destructor Documentation

ArrayIterator() [1/2]

ArrayIterator ( )

inline

Default constructor (not that you can dereference these).

Definition at line 124 of file ArrayIterator.h.

                   : m_array(nullptr), m_index(-1)
    {
    }

ArrayIterator() [2/2]

ArrayIterator ( const ArrayType *  array, int  index  )

inlineexplicit

Constructor.

Definition at line 129 of file ArrayIterator.h.

                                                             :
      m_array(array), m_index(index)
    {
    }

Member Function Documentation

deref_if_needed() [1/2]

static ValueType & deref_if_needed ( ValueType &  t )

inlinestaticprivate

Dereference if argument is a pointer to ValueType.

Definition at line 176 of file ArrayIterator.h.

    {
      return t;
    }

deref_if_needed() [2/2]

static ValueType & deref_if_needed ( ValueType *  t )

inlinestaticprivate

Dereference if argument is a pointer to ValueType.

Definition at line 182 of file ArrayIterator.h.

    {
      return *t;
    }

operator!=()

bool operator!= ( const ArrayIterator< ArrayType, ValueType > &  rhs ) const

inline

Check inequality.

Definition at line 156 of file ArrayIterator.h.

    {
      return !(*this == rhs);
    }

operator*()

ValueType & operator* ( ) const

inline

Dereference.

Definition at line 162 of file ArrayIterator.h.

    {
      return deref_if_needed((*m_array)[m_index]);
    }

operator++() [1/2]

ArrayIterator< ArrayType, ValueType > & operator++ ( )

inline

Prefix increment.

Definition at line 135 of file ArrayIterator.h.

    {
      ++m_index;
      return *this;
    }

operator++() [2/2]

ArrayIterator< ArrayType, ValueType > operator++ ( int  )

inline

Postfix increment.

Definition at line 142 of file ArrayIterator.h.

    {
      ArrayIterator<ArrayType, ValueType> old(*this);
      ++(*this);
      return old;
    }

operator->()

ValueType * operator-> ( ) const

inline

Dereference.

Definition at line 168 of file ArrayIterator.h.

    {
      return &(operator*());
    }

operator==()

bool operator== ( const ArrayIterator< ArrayType, ValueType > &  rhs ) const

inline

Check equality.

Definition at line 150 of file ArrayIterator.h.

    {
      return m_index == rhs.m_index && m_array == rhs.m_array;
    }

Member Data Documentation

m_array

const ArrayType* m_array

private

Array to iterate over.

Definition at line 188 of file ArrayIterator.h.

m_index

int m_index

private

Current index.

Definition at line 191 of file ArrayIterator.h.

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

• framework/utilities/include/ArrayIterator.h