mysql/detail/results_iterator.hpp

0001 //
0002 // Copyright (c) 2019-2023 Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
0003 //
0004 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0005 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 //
0007
0008 #ifndef BOOST_MYSQL_DETAIL_RESULTS_ITERATOR_HPP
0009 #define BOOST_MYSQL_DETAIL_RESULTS_ITERATOR_HPP
0010
0011 #include <boost/mysql/resultset.hpp>
0012 #include <boost/mysql/resultset_view.hpp>
0013
0014 #include <boost/mysql/detail/access.hpp>
0015 #include <boost/mysql/detail/execution_processor/results_impl.hpp>
0016
0017 namespace boost {
0018 namespace mysql {
0019 namespace detail {
0020
0021 class results_iterator
0022 {
0023     const results_impl* self_{};
0024     std::size_t index_{};
0025
0026 public:
0027     using value_type = resultset;
0028     using reference = resultset_view;
0029     using pointer = resultset_view;
0030     using difference_type = std::ptrdiff_t;
0031     using iterator_category = std::random_access_iterator_tag;
0032
0033     results_iterator() = default;
0034     results_iterator(const results_impl* self, std::size_t index) noexcept : self_(self), index_(index) {}
0035
0036     results_iterator& operator++() noexcept
0037     {
0038         ++index_;
0039         return *this;
0040     }
0041     results_iterator operator++(int) noexcept
0042     {
0043         auto res = *this;
0044         ++(*this);
0045         return res;
0046     }
0047     results_iterator& operator--() noexcept
0048     {
0049         --index_;
0050         return *this;
0051     }
0052     results_iterator operator--(int) noexcept
0053     {
0054         auto res = *this;
0055         --(*this);
0056         return res;
0057     }
0058     results_iterator& operator+=(std::ptrdiff_t n) noexcept
0059     {
0060         index_ += n;
0061         return *this;
0062     }
0063     results_iterator& operator-=(std::ptrdiff_t n) noexcept
0064     {
0065         index_ -= n;
0066         return *this;
0067     }
0068     results_iterator operator+(std::ptrdiff_t n) const noexcept
0069     {
0070         return results_iterator(self_, index_ + n);
0071     }
0072     results_iterator operator-(std::ptrdiff_t n) const noexcept { return *this + (-n); }
0073     std::ptrdiff_t operator-(results_iterator rhs) const noexcept { return index_ - rhs.index_; }
0074
0075     pointer operator->() const noexcept { return **this; }
0076     reference operator*() const noexcept { return (*this)[0]; }
0077     reference operator[](std::ptrdiff_t i) const noexcept
0078     {
0079         return access::construct<resultset_view>(*self_, index_ + i);
0080     }
0081
0082     bool operator==(results_iterator rhs) const noexcept { return index_ == rhs.index_; }
0083     bool operator!=(results_iterator rhs) const noexcept { return !(*this == rhs); }
0084     bool operator<(results_iterator rhs) const noexcept { return index_ < rhs.index_; }
0085     bool operator<=(results_iterator rhs) const noexcept { return index_ <= rhs.index_; }
0086     bool operator>(results_iterator rhs) const noexcept { return index_ > rhs.index_; }
0087     bool operator>=(results_iterator rhs) const noexcept { return index_ >= rhs.index_; }
0088
0089     std::size_t index() const noexcept { return index_; }
0090     const results_impl* obj() const noexcept { return self_; }
0091 };
0092
0093 inline results_iterator operator+(std::ptrdiff_t n, results_iterator it) noexcept { return it + n; }
0094
0095 }  // namespace detail
0096 }  // namespace mysql
0097 }  // namespace boost
0098
0099 #endif