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item_iterator.hpp
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#ifndef OSMIUM_MEMORY_ITEM_ITERATOR_HPP
#define OSMIUM_MEMORY_ITEM_ITERATOR_HPP
/*
This file is part of Osmium (https://osmcode.org/libosmium).
Copyright 2013-2025 Jochen Topf <jochen@topf.org> and others (see README).
Boost Software License - Version 1.0 - August 17th, 2003
Permission is hereby granted, free of charge, to any person or organization
obtaining a copy of the software and accompanying documentation covered by
this license (the "Software") to use, reproduce, display, distribute,
execute, and transmit the Software, and to prepare derivative works of the
Software, and to permit third-parties to whom the Software is furnished to
do so, all subject to the following:
The copyright notices in the Software and this entire statement, including
the above license grant, this restriction and the following disclaimer,
must be included in all copies of the Software, in whole or in part, and
all derivative works of the Software, unless such copies or derivative
works are solely in the form of machine-executable object code generated by
a source language processor.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
*/
#include <osmium/memory/item.hpp>
#include <osmium/osm/item_type.hpp>
#include <cassert>
#include <cstddef>
#include <iosfwd>
#include <iterator>
#include <type_traits>
namespace osmium {
namespace memory {
namespace detail {
template <typename T>
constexpr bool type_is_compatible(const osmium::item_type t) noexcept {
return T::is_compatible_to(t);
}
} // namespace detail
template <typename TMember>
class ItemIterator {
// This data_type is either 'unsigned char*' or 'const unsigned char*' depending
// on whether TMember is const. This allows this class to be used as an iterator and
// as a const_iterator.
using data_type = std::conditional_t<std::is_const<TMember>::value, const unsigned char*, unsigned char*>;
data_type m_data;
data_type m_end;
void advance_to_next_item_of_right_type() noexcept {
while (m_data != m_end &&
!detail::type_is_compatible<TMember>(reinterpret_cast<const osmium::memory::Item*>(m_data)->type())) {
m_data = reinterpret_cast<TMember*>(m_data)->next();
}
}
public:
using iterator_category = std::forward_iterator_tag;
using value_type = TMember;
using difference_type = std::ptrdiff_t;
using pointer = value_type*;
using reference = value_type&;
ItemIterator() noexcept :
m_data(nullptr),
m_end(nullptr) {
}
ItemIterator(data_type data, data_type end) noexcept :
m_data(data),
m_end(end) {
advance_to_next_item_of_right_type();
}
template <typename T>
ItemIterator<T> cast() const noexcept {
return ItemIterator<T>(m_data, m_end);
}
ItemIterator<TMember>& operator++() noexcept {
assert(m_data);
assert(m_data != m_end);
m_data = reinterpret_cast<TMember*>(m_data)->next();
advance_to_next_item_of_right_type();
return *static_cast<ItemIterator<TMember>*>(this);
}
ItemIterator<TMember>& advance_once() noexcept {
assert(m_data);
assert(m_data != m_end);
m_data = reinterpret_cast<TMember*>(m_data)->next();
return *static_cast<ItemIterator<TMember>*>(this);
}
ItemIterator<TMember> operator++(int) noexcept {
ItemIterator<TMember> tmp{*this};
operator++();
return tmp;
}
bool operator==(const ItemIterator<TMember>& rhs) const noexcept {
return m_data == rhs.m_data && m_end == rhs.m_end;
}
bool operator!=(const ItemIterator<TMember>& rhs) const noexcept {
return !(*this == rhs);
}
data_type data() noexcept {
assert(m_data);
return m_data;
}
const unsigned char* data() const noexcept {
assert(m_data);
return m_data;
}
TMember& operator*() const noexcept {
assert(m_data);
assert(m_data != m_end);
return *reinterpret_cast<TMember*>(m_data);
}
TMember* operator->() const noexcept {
assert(m_data);
assert(m_data != m_end);
return reinterpret_cast<TMember*>(m_data);
}
explicit operator bool() const noexcept {
return (m_data != nullptr) && (m_data != m_end);
}
template <typename TChar, typename TTraits>
void print(std::basic_ostream<TChar, TTraits>& out) const {
out << static_cast<const void*>(m_data);
}
}; // class ItemIterator
template <typename TChar, typename TTraits, typename TMember>
inline std::basic_ostream<TChar, TTraits>& operator<<(std::basic_ostream<TChar, TTraits>& out, const ItemIterator<TMember>& iter) {
iter.print(out);
return out;
}
template <typename T>
class ItemIteratorRange {
// This data_type is either 'unsigned char*' or
// 'const unsigned char*' depending on whether T is const.
using data_type = std::conditional_t<std::is_const<T>::value, const unsigned char*, unsigned char*>;
data_type m_begin;
data_type m_end;
public:
using iterator = ItemIterator<T>;
using const_iterator = ItemIterator<const T>;
ItemIteratorRange(data_type first, data_type last) noexcept :
m_begin(first),
m_end(last) {
}
iterator begin() noexcept {
return iterator{m_begin, m_end};
}
iterator end() noexcept {
return iterator{m_end, m_end};
}
const_iterator cbegin() const noexcept {
return const_iterator{m_begin, m_end};
}
const_iterator cend() const noexcept {
return const_iterator{m_end, m_end};
}
const_iterator begin() const noexcept {
return cbegin();
}
const_iterator end() const noexcept {
return cend();
}
std::size_t size() const noexcept {
if (m_begin == m_end) {
return 0;
}
return std::distance(cbegin(), cend());
}
bool empty() const noexcept {
return size() == 0;
}
}; // class ItemIteratorRange
} // namespace memory
} // namespace osmium
#endif // OSMIUM_MEMORY_ITEM_ITERATOR_HPP
osmium::memory::ItemIteratorRange
Definition item_iterator.hpp:175
osmium::memory::ItemIteratorRange::size
std::size_t size() const noexcept
Definition item_iterator.hpp:224
osmium::memory::ItemIteratorRange::empty
bool empty() const noexcept
Definition item_iterator.hpp:236
osmium::memory::ItemIteratorRange::end
const_iterator end() const noexcept
Definition item_iterator.hpp:215
osmium::memory::ItemIteratorRange::end
iterator end() noexcept
Definition item_iterator.hpp:199
osmium::memory::ItemIteratorRange::begin
const_iterator begin() const noexcept
Definition item_iterator.hpp:211
osmium::memory::ItemIteratorRange::cbegin
const_iterator cbegin() const noexcept
Definition item_iterator.hpp:203
osmium::memory::ItemIteratorRange::m_end
data_type m_end
Definition item_iterator.hpp:183
osmium::memory::ItemIteratorRange::data_type
std::conditional_t< std::is_const< T >::value, const unsigned char *, unsigned char * > data_type
Definition item_iterator.hpp:180
osmium::memory::ItemIteratorRange::m_begin
data_type m_begin
Definition item_iterator.hpp:182
osmium::memory::ItemIteratorRange::ItemIteratorRange
ItemIteratorRange(data_type first, data_type last) noexcept
Definition item_iterator.hpp:190
osmium::memory::ItemIteratorRange::begin
iterator begin() noexcept
Definition item_iterator.hpp:195
osmium::memory::ItemIteratorRange::cend
const_iterator cend() const noexcept
Definition item_iterator.hpp:207
osmium::memory::ItemIterator
Definition item_iterator.hpp:59
osmium::memory::ItemIterator::difference_type
std::ptrdiff_t difference_type
Definition item_iterator.hpp:81
osmium::memory::ItemIterator::data
const unsigned char * data() const noexcept
Definition item_iterator.hpp:140
osmium::memory::ItemIterator::ItemIterator
ItemIterator() noexcept
Definition item_iterator.hpp:85
osmium::memory::ItemIterator::operator==
bool operator==(const ItemIterator< TMember > &rhs) const noexcept
Definition item_iterator.hpp:127
osmium::memory::ItemIterator::m_end
data_type m_end
Definition item_iterator.hpp:68
osmium::memory::ItemIterator::ItemIterator
ItemIterator(data_type data, data_type end) noexcept
Definition item_iterator.hpp:90
osmium::memory::ItemIterator::operator*
TMember & operator*() const noexcept
Definition item_iterator.hpp:145
osmium::memory::ItemIterator::operator++
ItemIterator< TMember > operator++(int) noexcept
Definition item_iterator.hpp:121
osmium::memory::ItemIterator::operator!=
bool operator!=(const ItemIterator< TMember > &rhs) const noexcept
Definition item_iterator.hpp:131
osmium::memory::ItemIterator::operator->
TMember * operator->() const noexcept
Definition item_iterator.hpp:151
osmium::memory::ItemIterator::cast
ItemIterator< T > cast() const noexcept
Definition item_iterator.hpp:97
osmium::memory::ItemIterator::reference
value_type & reference
Definition item_iterator.hpp:83
osmium::memory::ItemIterator::operator++
ItemIterator< TMember > & operator++() noexcept
Definition item_iterator.hpp:101
osmium::memory::ItemIterator::value_type
TMember value_type
Definition item_iterator.hpp:80
osmium::memory::ItemIterator::print
void print(std::basic_ostream< TChar, TTraits > &out) const
Definition item_iterator.hpp:162
osmium::memory::ItemIterator::data_type
std::conditional_t< std::is_const< TMember >::value, const unsigned char *, unsigned char * > data_type
Definition item_iterator.hpp:65
osmium::memory::ItemIterator::m_data
data_type m_data
Definition item_iterator.hpp:67
osmium::memory::ItemIterator::advance_once
ItemIterator< TMember > & advance_once() noexcept
Definition item_iterator.hpp:114
osmium::memory::ItemIterator::pointer
value_type * pointer
Definition item_iterator.hpp:82
osmium::memory::ItemIterator::advance_to_next_item_of_right_type
void advance_to_next_item_of_right_type() noexcept
Definition item_iterator.hpp:70
osmium::memory::ItemIterator::iterator_category
std::forward_iterator_tag iterator_category
Definition item_iterator.hpp:79
osmium::memory::ItemIterator::data
data_type data() noexcept
Definition item_iterator.hpp:135
osmium::memory::Item
Definition item.hpp:105
item.hpp
item_type.hpp
detail
Definition attr.hpp:342
osmium::memory::operator<<
std::basic_ostream< TChar, TTraits > & operator<<(std::basic_ostream< TChar, TTraits > &out, const CollectionIterator< TMember > &iter)
Definition collection.hpp:111
osmium
Namespace for everything in the Osmium library.
Definition assembler.hpp:53
osmium::item_type
item_type
Definition item_type.hpp:45