gnss-sim/3rdparty/boost/mysql/detail/rows_iterator.hpp

113 lines
3.3 KiB
C++

//
// Copyright (c) 2019-2024 Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef BOOST_MYSQL_DETAIL_ROWS_ITERATOR_HPP
#define BOOST_MYSQL_DETAIL_ROWS_ITERATOR_HPP
#include <boost/mysql/field_view.hpp>
#include <boost/mysql/row.hpp>
#include <boost/mysql/row_view.hpp>
#include <boost/mysql/detail/access.hpp>
#include <cstddef>
#include <cstdint>
#include <iterator>
namespace boost {
namespace mysql {
namespace detail {
inline row_view row_slice(const field_view* fields, std::size_t num_columns, std::size_t offset) noexcept
{
return access::construct<row_view>(fields + num_columns * offset, num_columns);
}
class rows_iterator
{
const field_view* fields_{nullptr};
std::size_t num_columns_{0};
std::size_t row_num_{0};
public:
using value_type = row;
using reference = row_view;
using pointer = row_view;
using difference_type = std::ptrdiff_t;
using iterator_category = std::random_access_iterator_tag;
rows_iterator() = default;
rows_iterator(const field_view* fields, std::size_t num_columns, std::size_t rownum) noexcept
: fields_(fields), num_columns_(num_columns), row_num_(rownum)
{
}
rows_iterator& operator++() noexcept
{
++row_num_;
return *this;
}
rows_iterator operator++(int) noexcept
{
auto res = *this;
++(*this);
return res;
}
rows_iterator& operator--() noexcept
{
--row_num_;
return *this;
}
rows_iterator operator--(int) noexcept
{
auto res = *this;
--(*this);
return res;
}
rows_iterator& operator+=(std::ptrdiff_t n) noexcept
{
row_num_ += n;
return *this;
}
rows_iterator& operator-=(std::ptrdiff_t n) noexcept
{
row_num_ -= n;
return *this;
}
rows_iterator operator+(std::ptrdiff_t n) const noexcept
{
return rows_iterator(fields_, num_columns_, row_num_ + n);
}
rows_iterator operator-(std::ptrdiff_t n) const noexcept
{
return rows_iterator(fields_, num_columns_, row_num_ - n);
}
std::ptrdiff_t operator-(rows_iterator rhs) const noexcept { return row_num_ - rhs.row_num_; }
pointer operator->() const noexcept { return **this; }
reference operator*() const noexcept { return (*this)[0]; }
reference operator[](std::ptrdiff_t i) const noexcept
{
return row_slice(fields_, num_columns_, row_num_ + i);
}
bool operator==(rows_iterator rhs) const noexcept { return row_num_ == rhs.row_num_; }
bool operator!=(rows_iterator rhs) const noexcept { return !(*this == rhs); }
bool operator<(rows_iterator rhs) const noexcept { return row_num_ < rhs.row_num_; }
bool operator<=(rows_iterator rhs) const noexcept { return row_num_ <= rhs.row_num_; }
bool operator>(rows_iterator rhs) const noexcept { return row_num_ > rhs.row_num_; }
bool operator>=(rows_iterator rhs) const noexcept { return row_num_ >= rhs.row_num_; }
};
inline rows_iterator operator+(std::ptrdiff_t n, rows_iterator it) noexcept { return it + n; }
} // namespace detail
} // namespace mysql
} // namespace boost
#endif