forked from boostorg/iterator
56 lines
1.2 KiB
Plaintext
56 lines
1.2 KiB
Plaintext
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[section:traits Iterator Traits]
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`std::iterator_traits` provides access to five associated types
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of any iterator: its `value_type`, `reference`, `pointer`,
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`iterator_category`, and `difference_type`. Unfortunately,
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such a "multi-valued" traits template can be difficult to use in a
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metaprogramming context. `<boost/iterator/iterator_traits.hpp>`
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provides access to these types using a standard metafunctions_.
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[h2 Synopsis]
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Header `<boost/iterator/iterator_traits.hpp>`:
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template <class Iterator>
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struct iterator_value
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{
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typedef typename
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std::iterator_traits<Iterator>::value_type
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type;
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};
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template <class Iterator>
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struct iterator_reference
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{
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typedef typename
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std::iterator_traits<Iterator>::reference
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type;
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};
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template <class Iterator>
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struct iterator_pointer
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{
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typedef typename
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std::iterator_traits<Iterator>::pointer
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type;
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};
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template <class Iterator>
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struct iterator_difference
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{
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typedef typename
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detail::iterator_traits<Iterator>::difference_type
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type;
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};
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template <class Iterator>
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struct iterator_category
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{
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typedef typename
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detail::iterator_traits<Iterator>::iterator_category
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type;
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};
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[endsect]
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