circular_iterator
20.34.0
An iterator wrapper where increments and decrements will roll around the boundaries of an iterator range.
It is constructed with the begin and end of the range, plus an optional start position.
May be used with forward, bidirectional and random access iterators.
template <typename TIterator>
etl::circular_iterator final;
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Types
value_type
difference_type
pointer
reference
iterator_category
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Constructors
ETL_CONSTEXPR14 circular_iterator()
Default constructor.
ETL_CONSTEXPR14 circular_iterator(TIterator itr_begin, TIterator itr_end)
Construct from iterators.
ETL_CONSTEXPR14 circular_iterator(TIterator itr_begin, TIterator itr_end, TIterator itr_start)
Construct from iterators and start position
ETL_CONSTEXPR14 circular_iterator(const circular_iterator& other)
Copy constructor
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Member functions
ETL_CONSTEXPR14 circular_iterator& operator =(const circular_iterator& other)
Assignment operator
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ETL_CONSTEXPR14 size_t size() const
Returns the length of the range.
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ETL_CONSTEXPR14 bool empty() const
Returns true if the range is empty.
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ETL_CONSTEXPR14 value_type operator *()
Dereference operator
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ETL_CONSTEXPR14 const value_type operator *() const
Dereference operator
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ETL_CONSTEXPR14 TIterator operator ->()
-> operator
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ETL_CONSTEXPR14 const TIterator operator ->() const
-> operator
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ETL_CONSTEXPR14 operator TIterator() const
Conversion operator
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ETL_CONSTEXPR14 TIterator current() const
Conversion to the base iterator type
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ETL_CONSTEXPR14 circular_iterator& operator ++()
Increment
Forward iterator
Bidirectional iterator
Random access iterator
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ETL_CONSTEXPR14 circular_iterator operator ++(int)
Increment
Forward iterator
Bidirectional iterator
Random access iterator
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ETL_CONSTEXPR14 circular_iterator& operator --()
Decrement
Bidirectional iterator
Random access iterator
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ETL_CONSTEXPR14 circular_iterator operator --(int)
Decrement
Bidirectional iterator
Random access iterator
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ETL_CONSTEXPR14 circular_iterator& operator +=(difference_type offset)
+= operator
Random access iterator
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ETL_CONSTEXPR14 circular_iterator& operator -=(typename
etl::iterator_traits<TIterator>::difference_type
offset)
-= operator
Random access iterator
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Non-member functions
template <typename TIterator>
ETL_CONSTEXPR14
typename etl::iterator_traits<TIterator>::difference_type
operator - (etl::circular_iterator<TIterator>& lhs, etl::circular_iterator<TIterator>& rhs)
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template <typename TIterator>
ETL_CONSTEXPR14
bool operator ==(const etl::circular_iterator<TIterator>& lhs,
const etl::circular_iterator<TIterator>& rhs)
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template <typename TIterator>
ETL_CONSTEXPR14 bool operator ==(const etl::circular_iterator<TIterator>& lhs,
TIterator rhs)
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template <typename TIterator>
ETL_CONSTEXPR14 bool operator ==(TIterator lhs,
const etl::circular_iterator<TIterator>& rhs)
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template <typename TIterator>
ETL_CONSTEXPR14 bool operator !=(const etl::circular_iterator<TIterator>& lhs,
const etl::circular_iterator<TIterator>& rhs)
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template <typename TIterator>
ETL_CONSTEXPR14 bool operator !=(const etl::circular_iterator<TIterator>& lhs,
TIterator rhs)
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template <typename TIterator>
ETL_CONSTEXPR14 bool operator !=(TIterator& lhs,
const etl::circular_iterator<TIterator>& rhs)
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Example
std::list<int> data{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
// The start position to loop from.
std::list<int>::const_iterator> start = data.begin();
std::advance(start, 2);
// Create circular iterators.
etl::circular_iterator<std::list<int>::const_iterator>> cli(data.begin(), data.end(), start);
etl::circular_iterator<std::list<int>::const_reverse_iterator>> clri(data.rbegin(), data.rend);
// Loop 10 times, taking every third value, starting from the third element for the forward iterator and
from the end for the reverse iterator.
for (int = 0; i < 10; ++i)
{
std::cout << "(" << *cli << "," << *clrl << ")";
std::advance(cli, 3);
std::advance(clri, 3);
}
Prints the following
(2,9)(5,6)(8,3)(1,0)(4,7)(7,4)(0,1)(3,8)(6,5)(9,2)