apt/apt-pkg/cacheset.h

// -*- mode: cpp; mode: fold -*-
// Description								/*{{{*/
/** \file cacheset.h
   Wrappers around std::set to have set::iterators which behave
   similar to the Iterators of the cache structures.

   Provides also a few helper methods which work with these sets */
									/*}}}*/
#ifndef APT_CACHESET_H
#define APT_CACHESET_H
// Include Files							/*{{{*/
#include <fstream>
#include <map>
#include <set>
#if __cplusplus >= 201103L
#include <forward_list>
#include <initializer_list>
#include <unordered_set>
#endif
#include <algorithm>
#include <deque>
#include <iterator>
#include <list>
#include <string>
#include <vector>

#include <stddef.h>

#include <apt-pkg/error.h>
#include <apt-pkg/macros.h>
#include <apt-pkg/pkgcache.h>

#ifndef APT_8_CLEANER_HEADERS
#include <apt-pkg/cachefile.h>
#endif
#ifndef APT_10_CLEANER_HEADERS
#include <iostream>
#endif
									/*}}}*/

class pkgCacheFile;

namespace APT {
class PackageContainerInterface;
class VersionContainerInterface;

class CacheSetHelper {							/*{{{*/
/** \class APT::CacheSetHelper
    Simple base class with a lot of virtual methods which can be overridden
    to alter the behavior or the output of the CacheSets.

    This helper is passed around by the static methods in the CacheSets and
    used every time they hit an error condition or something could be
    printed out.
*/
public:									/*{{{*/
	CacheSetHelper(bool const ShowError = true,
		GlobalError::MsgType ErrorType = GlobalError::ERROR);
	virtual ~CacheSetHelper();

	enum PkgSelector { UNKNOWN, REGEX, TASK, FNMATCH, PACKAGENAME, STRING };

	virtual bool PackageFrom(enum PkgSelector const select, PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string const &pattern);

	virtual bool PackageFromCommandLine(PackageContainerInterface * const pci, pkgCacheFile &Cache, const char **cmdline);

	struct PkgModifier {
		enum Position { NONE, PREFIX, POSTFIX };
		unsigned short ID;
		const char * const Alias;
		Position Pos;
		PkgModifier (unsigned short const &id, const char * const alias, Position const &pos) : ID(id), Alias(alias), Pos(pos) {}
	};
	virtual bool PackageFromModifierCommandLine(unsigned short &modID, PackageContainerInterface * const pci,
					    pkgCacheFile &Cache, const char * cmdline,
					    std::list<PkgModifier> const &mods);

	APT_DEPRECATED_MSG("use .PackageFrom(PACKAGENAME, …) instead") pkgCache::PkgIterator PackageFromName(pkgCacheFile &Cache, std::string const &pattern);

	/** \brief be notified about the package being selected via pattern
	 *
	 * Main use is probably to show a message to the user what happened
	 *
	 * \param pkg is the package which was selected
	 * \param select is the selection method which choose the package
	 * \param pattern is the string used by the selection method to pick the package
	 */
	virtual void showPackageSelection(pkgCache::PkgIterator const &pkg, PkgSelector const select, std::string const &pattern);
	// use the method above instead, react only on the type you need and let the base handle the rest if need be
	// this allows us to add new selection methods without breaking the ABI constantly with new virtual methods
	APT_DEPRECATED_MSG("override .showPackageSelection and select with switch") virtual void showTaskSelection(pkgCache::PkgIterator const &pkg, std::string const &pattern);
	APT_DEPRECATED_MSG("override .showPackageSelection and select with switch") virtual void showRegExSelection(pkgCache::PkgIterator const &pkg, std::string const &pattern);
	APT_DEPRECATED_MSG("override .showPackageSelection and select with switch") virtual void showFnmatchSelection(pkgCache::PkgIterator const &pkg, std::string const &pattern);

	/** \brief be notified if a package can't be found via pattern
	 *
	 * Can be used to show a message as well as to try something else to make it match
	 *
	 * \param select is the method tried for selection
	 * \param pci is the container the package should be inserted in
	 * \param Cache is the package universe available
	 * \param pattern is the string not matching anything
	 */
	virtual void canNotFindPackage(enum PkgSelector const select, PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string const &pattern);
	// same as above for showPackageSelection
	APT_DEPRECATED_MSG("override .canNotFindPackage and select with switch") virtual void canNotFindTask(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string pattern);
	APT_DEPRECATED_MSG("override .canNotFindPackage and select with switch") virtual void canNotFindRegEx(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string pattern);
	APT_DEPRECATED_MSG("override .canNotFindPackage and select with switch") virtual void canNotFindFnmatch(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string pattern);
	APT_DEPRECATED_MSG("override .canNotFindPackage and select with switch") virtual void canNotFindPackage(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string const &str);

	/** \brief specifies which version(s) we want to refer to */
	enum VerSelector {
		/** by release string */
		RELEASE,
		/** by version number string */
		VERSIONNUMBER,
		/** All versions */
		ALL,
		/** Candidate and installed version */
		CANDANDINST,
		/** Candidate version */
		CANDIDATE,
		/** Installed version */
		INSTALLED,
		/** Candidate or if non installed version */
		CANDINST,
		/** Installed or if non candidate version */
		INSTCAND,
		/** Newest version */
		NEWEST
	};

	/** \brief be notified about the version being selected via pattern
	 *
	 * Main use is probably to show a message to the user what happened
	 * Note that at the moment this method is only called for RELEASE
	 * and VERSION selections, not for the others.
	 *
	 * \param Pkg is the package which was selected for
	 * \param Ver is the version selected
	 * \param select is the selection method which choose the version
	 * \param pattern is the string used by the selection method to pick the version
	 */
	virtual void showVersionSelection(pkgCache::PkgIterator const &Pkg, pkgCache::VerIterator const &Ver,
	      enum VerSelector const select, std::string const &pattern);
	APT_DEPRECATED_MSG("use .showVersionSelection instead, similar to .showPackageSelection") virtual void showSelectedVersion(pkgCache::PkgIterator const &Pkg, pkgCache::VerIterator const Ver,
				 std::string const &ver, bool const verIsRel);

	/** \brief be notified if a version can't be found for a package
	 *
	 * Main use is probably to show a message to the user what happened
	 *
	 * \param select is the method tried for selection
	 * \param vci is the container the version should be inserted in
	 * \param Cache is the package universe available
	 * \param Pkg is the package we wanted a version from
	 */
	virtual void canNotFindVersion(enum VerSelector const select, VersionContainerInterface * const vci, pkgCacheFile &Cache, pkgCache::PkgIterator const &Pkg);
	APT_DEPRECATED_MSG("override .canNotFindVersion and select via switch") virtual void canNotFindAllVer(VersionContainerInterface * const vci, pkgCacheFile &Cache, pkgCache::PkgIterator const &Pkg);
	APT_DEPRECATED_MSG("override .canNotFindVersion and select via switch") virtual void canNotFindInstCandVer(VersionContainerInterface * const vci, pkgCacheFile &Cache,
				pkgCache::PkgIterator const &Pkg);
	APT_DEPRECATED_MSG("override .canNotFindVersion and select via switch") virtual void canNotFindCandInstVer(VersionContainerInterface * const vci,
				pkgCacheFile &Cache,
				pkgCache::PkgIterator const &Pkg);

	// the difference between canNotFind and canNotGet is that the later is more low-level
	// and called from other places: In this case looking into the code is the only real answer…
	virtual pkgCache::VerIterator canNotGetVersion(enum VerSelector const select, pkgCacheFile &Cache, pkgCache::PkgIterator const &Pkg);
	APT_DEPRECATED_MSG("override .canNotGetVersion and select via switch") virtual pkgCache::VerIterator canNotFindNewestVer(pkgCacheFile &Cache,
				pkgCache::PkgIterator const &Pkg);
	APT_DEPRECATED_MSG("override .canNotGetVersion and select via switch") virtual pkgCache::VerIterator canNotFindCandidateVer(pkgCacheFile &Cache,
				pkgCache::PkgIterator const &Pkg);
	APT_DEPRECATED_MSG("override .canNotGetVersion and select via switch") virtual pkgCache::VerIterator canNotFindInstalledVer(pkgCacheFile &Cache,
				pkgCache::PkgIterator const &Pkg);

	virtual pkgCache::PkgIterator canNotFindPkgName(pkgCacheFile &Cache, std::string const &str);

	bool showErrors() const { return ShowError; }
	bool showErrors(bool const newValue) { if (ShowError == newValue) return ShowError; else return ((ShowError = newValue) == false); }
	GlobalError::MsgType errorType() const { return ErrorType; }
	GlobalError::MsgType errorType(GlobalError::MsgType const &newValue)
	{
		if (ErrorType == newValue) return ErrorType;
		else {
			GlobalError::MsgType const &oldValue = ErrorType;
			ErrorType = newValue;
			return oldValue;
		}
	}

									/*}}}*/
protected:
	bool ShowError;
	GlobalError::MsgType ErrorType;

	pkgCache::VerIterator canNotGetInstCandVer(pkgCacheFile &Cache,
		pkgCache::PkgIterator const &Pkg);
	pkgCache::VerIterator canNotGetCandInstVer(pkgCacheFile &Cache,
		pkgCache::PkgIterator const &Pkg);

	bool PackageFromTask(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string pattern);
	bool PackageFromRegEx(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string pattern);
	bool PackageFromFnmatch(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string pattern);
	bool PackageFromPackageName(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string pattern);
	bool PackageFromString(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string const &pattern);
private:
	void * const d;
};									/*}}}*/
// Iterator templates for our Containers				/*{{{*/
template<typename Interface, typename Master, typename iterator_type, typename container_iterator, typename container_value> class Container_iterator_base :
   public std::iterator<typename std::iterator_traits<container_iterator>::iterator_category, container_value>,
   public Interface::template iterator_base<iterator_type>
{
protected:
	container_iterator _iter;
public:
	explicit Container_iterator_base(container_iterator i) : _iter(i) {}
	inline container_value operator*(void) const { return static_cast<iterator_type const*>(this)->getType(); };
	operator container_iterator(void) const { return _iter; }
	inline iterator_type& operator++() { ++_iter; return static_cast<iterator_type&>(*this); }
	inline iterator_type operator++(int) { iterator_type tmp(*this); operator++(); return tmp; }
	inline iterator_type operator+(typename container_iterator::difference_type const &n) { return iterator_type(_iter + n); }
	inline iterator_type operator+=(typename container_iterator::difference_type const &n) { _iter += n; return static_cast<iterator_type&>(*this); }
	inline iterator_type& operator--() { --_iter;; return static_cast<iterator_type&>(*this); }
	inline iterator_type operator--(int) { iterator_type tmp(*this); operator--(); return tmp; }
	inline iterator_type operator-(typename container_iterator::difference_type const &n) { return iterator_type(_iter - n); }
	inline typename container_iterator::difference_type operator-(iterator_type const &b) { return (_iter - b._iter); }
	inline iterator_type operator-=(typename container_iterator::difference_type const &n) { _iter -= n; return static_cast<iterator_type&>(*this); }
	inline bool operator!=(iterator_type const &i) const { return _iter != i._iter; }
	inline bool operator==(iterator_type const &i) const { return _iter == i._iter; }
	inline bool operator<(iterator_type const &i) const { return _iter < i._iter; }
	inline bool operator>(iterator_type const &i) const { return _iter > i._iter; }
	inline bool operator<=(iterator_type const &i) const { return _iter <= i._iter; }
	inline bool operator>=(iterator_type const &i) const { return _iter >= i._iter; }
	inline typename container_iterator::reference operator[](typename container_iterator::difference_type const &n) const { return _iter[n]; }

	friend std::ostream& operator<<(std::ostream& out, iterator_type i) { return operator<<(out, *i); }
	friend Master;
};
template<class Interface, class Container, class Master> class Container_const_iterator :
   public Container_iterator_base<Interface, Master, Container_const_iterator<Interface, Container, Master>, typename Container::const_iterator, typename Container::value_type>
{
	typedef Container_const_iterator<Interface, Container, Master> iterator_type;
	typedef typename Container::const_iterator container_iterator;
public:
	explicit Container_const_iterator(container_iterator i) :
	   Container_iterator_base<Interface, Master, iterator_type, container_iterator, typename Container::value_type>(i) {}

	inline typename Container::value_type getType(void) const { return *this->_iter; }
};
template<class Interface, class Container, class Master> class Container_iterator :
   public Container_iterator_base<Interface, Master, Container_iterator<Interface, Container, Master>, typename Container::iterator, typename Container::value_type>
{
	typedef Container_iterator<Interface, Container, Master> iterator_type;
	typedef typename Container::iterator container_iterator;
public:
	explicit Container_iterator(container_iterator i) :
	   Container_iterator_base<Interface, Master, iterator_type, container_iterator, typename Container::value_type>(i) {}

	operator typename Master::const_iterator() { return typename Master::const_iterator(this->_iter); }
	inline iterator_type& operator=(iterator_type const &i) { this->_iter = i._iter; return static_cast<iterator_type&>(*this); }
	inline iterator_type& operator=(container_iterator const &i) { this->_iter = i; return static_cast<iterator_type&>(*this); }
	inline typename Container::iterator::reference operator*(void) const { return *this->_iter; }

	inline typename Container::value_type getType(void) const { return *this->_iter; }
};
template<class Interface, class Container, class Master> class Container_const_reverse_iterator :
   public Container_iterator_base<Interface, Master, Container_const_reverse_iterator<Interface, Container, Master>, typename Container::const_reverse_iterator, typename Container::value_type>
{
	typedef Container_const_reverse_iterator<Interface, Container, Master> iterator_type;
	typedef typename Container::const_reverse_iterator container_iterator;
public:
	explicit Container_const_reverse_iterator(container_iterator i) :
	   Container_iterator_base<Interface, Master, iterator_type, container_iterator, typename Container::value_type>(i) {}

	inline typename Container::value_type getType(void) const { return *this->_iter; }
};
template<class Interface, class Container, class Master> class Container_reverse_iterator :
   public Container_iterator_base<Interface, Master, Container_reverse_iterator<Interface, Container, Master>, typename Container::reverse_iterator, typename Container::value_type>
{
	typedef Container_reverse_iterator<Interface, Container, Master> iterator_type;
	typedef typename Container::reverse_iterator container_iterator;
public:
	explicit Container_reverse_iterator(container_iterator i) :
	   Container_iterator_base<Interface, Master, iterator_type, container_iterator, typename Container::value_type>(i) {}

	operator typename Master::const_iterator() { return typename Master::const_iterator(this->_iter); }
	inline iterator_type& operator=(iterator_type const &i) { this->_iter = i._iter; return static_cast<iterator_type&>(*this); }
	inline iterator_type& operator=(container_iterator const &i) { this->_iter = i; return static_cast<iterator_type&>(*this); }
	inline typename Container::reverse_iterator::reference operator*(void) const { return *this->_iter; }

	inline typename Container::value_type getType(void) const { return *this->_iter; }
};
									/*}}}*/
class PackageContainerInterface {					/*{{{*/
/** \class PackageContainerInterface

 * Interface ensuring that all operations can be executed on the yet to
 * define concrete PackageContainer - access to all methods is possible,
 * but in general the wrappers provided by the PackageContainer template
 * are nicer to use.

 * This class mostly protects use from the need to write all implementation
 * of the methods working on containers in the template */
public:
	template<class Itr> class iterator_base {			/*{{{*/
		pkgCache::PkgIterator getType() const { return static_cast<Itr const*>(this)->getType(); };
	public:
		operator pkgCache::PkgIterator(void) const { return getType(); }

		inline const char *Name() const {return getType().Name(); }
		inline std::string FullName(bool const Pretty) const { return getType().FullName(Pretty); }
		inline std::string FullName() const { return getType().FullName(); }
		APT_DEPRECATED_MSG("Use the .Section method of VerIterator instead") inline const char *Section() const {
		   APT_IGNORE_DEPRECATED_PUSH
		      return getType().Section();
		   APT_IGNORE_DEPRECATED_POP
		}
		inline bool Purge() const {return getType().Purge(); }
		inline const char *Arch() const {return getType().Arch(); }
		inline pkgCache::GrpIterator Group() const { return getType().Group(); }
		inline pkgCache::VerIterator VersionList() const { return getType().VersionList(); }
		inline pkgCache::VerIterator CurrentVer() const { return getType().CurrentVer(); }
		inline pkgCache::DepIterator RevDependsList() const { return getType().RevDependsList(); }
		inline pkgCache::PrvIterator ProvidesList() const { return getType().ProvidesList(); }
		inline pkgCache::PkgIterator::OkState State() const { return getType().State(); }
		APT_DEPRECATED_MSG("This method does not respect apt_preferences! Use pkgDepCache::GetCandidateVersion(Pkg)") inline const char *CandVersion() const { return getType().CandVersion(); }
		inline const char *CurVersion() const { return getType().CurVersion(); }
		inline pkgCache *Cache() const { return getType().Cache(); }
		inline unsigned long Index() const {return getType().Index();}
		// we have only valid iterators here
		inline bool end() const { return false; }

		inline pkgCache::Package const * operator->() const {return &*getType();}
	};
									/*}}}*/

	virtual bool insert(pkgCache::PkgIterator const &P) = 0;
	virtual bool empty() const = 0;
	virtual void clear() = 0;
	virtual size_t size() const = 0;

	enum APT_DEPRECATED_MSG("Use CacheSetHelper::PkgSelector instead") Constructor { UNKNOWN = CacheSetHelper::UNKNOWN,
		REGEX = CacheSetHelper::REGEX,
		TASK = CacheSetHelper::TASK,
		FNMATCH = CacheSetHelper::FNMATCH };
APT_IGNORE_DEPRECATED_PUSH
	void setConstructor(Constructor const by) { ConstructedBy = (CacheSetHelper::PkgSelector)by; }
APT_IGNORE_DEPRECATED_POP

	void setConstructor(CacheSetHelper::PkgSelector const by) { ConstructedBy = by; }
	CacheSetHelper::PkgSelector getConstructor() const { return ConstructedBy; }
	PackageContainerInterface();
	explicit PackageContainerInterface(CacheSetHelper::PkgSelector const by);
	PackageContainerInterface& operator=(PackageContainerInterface const &other);
	virtual ~PackageContainerInterface();

	APT_DEPRECATED_MSG("Use helper.PackageFrom(CacheSetHelper::TASK, …) instead") static bool FromTask(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string pattern, CacheSetHelper &helper) {
	   return helper.PackageFrom(CacheSetHelper::TASK, pci, Cache, pattern); }
	APT_DEPRECATED_MSG("Use helper.PackageFrom(CacheSetHelper::REGEX, …) instead") static bool FromRegEx(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string pattern, CacheSetHelper &helper) {
	   return helper.PackageFrom(CacheSetHelper::REGEX, pci, Cache, pattern); }
	APT_DEPRECATED_MSG("Use helper.PackageFrom(CacheSetHelper::FNMATCH, …) instead") static bool FromFnmatch(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string pattern, CacheSetHelper &helper) {
	   return helper.PackageFrom(CacheSetHelper::FNMATCH, pci, Cache, pattern); }
	APT_DEPRECATED_MSG("Use helper.PackageFrom(CacheSetHelper::PACKAGENAME, …) instead") static bool FromGroup(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string pattern, CacheSetHelper &helper) {
	   return helper.PackageFrom(CacheSetHelper::PACKAGENAME, pci, Cache, pattern); }
	APT_DEPRECATED_MSG("Use helper.PackageFrom(CacheSetHelper::STRING, …) instead") static bool FromString(PackageContainerInterface * const pci, pkgCacheFile &Cache, std::string const &pattern, CacheSetHelper &helper) {
	   return helper.PackageFrom(CacheSetHelper::STRING, pci, Cache, pattern); }
	APT_DEPRECATED_MSG("Use helper.PackageFromCommandLine instead") static bool FromCommandLine(PackageContainerInterface * const pci, pkgCacheFile &Cache, const char **cmdline, CacheSetHelper &helper) {
	   return helper.PackageFromCommandLine(pci, Cache, cmdline); }

	APT_DEPRECATED_MSG("enum moved to CacheSetHelper::PkgModifier") typedef CacheSetHelper::PkgModifier Modifier;

APT_IGNORE_DEPRECATED_PUSH
	APT_DEPRECATED_MSG("Use helper.PackageFromName instead") static pkgCache::PkgIterator FromName(pkgCacheFile &Cache, std::string const &pattern, CacheSetHelper &helper) {
	   return helper.PackageFromName(Cache, pattern); }
	APT_DEPRECATED_MSG("Use helper.PackageFromModifierCommandLine instead") static bool FromModifierCommandLine(unsigned short &modID, PackageContainerInterface * const pci,
	      pkgCacheFile &Cache, const char * cmdline,
	      std::list<Modifier> const &mods, CacheSetHelper &helper) {
	   return helper.PackageFromModifierCommandLine(modID, pci, Cache, cmdline, mods); }
APT_IGNORE_DEPRECATED_POP

private:
	CacheSetHelper::PkgSelector ConstructedBy;
	void * const d;
};
									/*}}}*/
template<class Container> class PackageContainer : public PackageContainerInterface {/*{{{*/
/** \class APT::PackageContainer

    Simple wrapper around a container class like std::set to provide a similar
    interface to a set of packages as to the complete set of all packages in the
    pkgCache. */
	Container _cont;
public:									/*{{{*/
	/** \brief smell like a pkgCache::PkgIterator */
	typedef Container_const_iterator<PackageContainerInterface, Container, PackageContainer> const_iterator;
	typedef Container_iterator<PackageContainerInterface, Container, PackageContainer> iterator;
	typedef Container_const_reverse_iterator<PackageContainerInterface, Container, PackageContainer> const_reverse_iterator;
	typedef Container_reverse_iterator<PackageContainerInterface, Container, PackageContainer> reverse_iterator;
	typedef typename Container::value_type value_type;
	typedef typename Container::pointer pointer;
	typedef typename Container::const_pointer const_pointer;
	typedef typename Container::reference reference;
	typedef typename Container::const_reference const_reference;
	typedef typename Container::difference_type difference_type;
	typedef typename Container::size_type size_type;
	typedef typename Container::allocator_type allocator_type;

	bool insert(pkgCache::PkgIterator const &P) APT_OVERRIDE { if (P.end() == true) return false; _cont.insert(P); return true; }
	template<class Cont> void insert(PackageContainer<Cont> const &pkgcont) { _cont.insert((typename Cont::const_iterator)pkgcont.begin(), (typename Cont::const_iterator)pkgcont.end()); }
	void insert(const_iterator begin, const_iterator end) { _cont.insert(begin, end); }

	bool empty() const APT_OVERRIDE { return _cont.empty(); }
	void clear() APT_OVERRIDE { return _cont.clear(); }
	size_t size() const APT_OVERRIDE { return _cont.size(); }
#if __GNUC__ >= 5 || (__GNUC_MINOR__ >= 9 && __GNUC__ >= 4)
	iterator erase( const_iterator pos ) { return iterator(_cont.erase(pos._iter)); }
	iterator erase( const_iterator first, const_iterator last ) { return iterator(_cont.erase(first._iter, last._iter)); }
#else
	iterator erase( iterator pos ) { return iterator(_cont.erase(pos._iter)); }
	iterator erase( iterator first, iterator last ) { return iterator(_cont.erase(first._iter, last._iter)); }
#endif
	const_iterator begin() const { return const_iterator(_cont.begin()); }
	const_iterator end() const { return const_iterator(_cont.end()); }
	const_reverse_iterator rbegin() const { return const_reverse_iterator(_cont.rbegin()); }
	const_reverse_iterator rend() const { return const_reverse_iterator(_cont.rend()); }
#if __cplusplus >= 201103L
	const_iterator cbegin() const { return const_iterator(_cont.cbegin()); }
	const_iterator cend() const { return const_iterator(_cont.cend()); }
	const_reverse_iterator crbegin() const { return const_reverse_iterator(_cont.crbegin()); }
	const_reverse_iterator crend() const { return const_reverse_iterator(_cont.crend()); }
#endif
	iterator begin() { return iterator(_cont.begin()); }
	iterator end() { return iterator(_cont.end()); }
	reverse_iterator rbegin() { return reverse_iterator(_cont.rbegin()); }
	reverse_iterator rend() { return reverse_iterator(_cont.rend()); }
	const_iterator find(pkgCache::PkgIterator const &P) const { return const_iterator(_cont.find(P)); }

	PackageContainer() : PackageContainerInterface(CacheSetHelper::UNKNOWN) {}
	explicit PackageContainer(CacheSetHelper::PkgSelector const &by) : PackageContainerInterface(by) {}
APT_IGNORE_DEPRECATED_PUSH
	APT_DEPRECATED_MSG("Construct with a CacheSetHelper::PkgSelector instead") explicit PackageContainer(Constructor const &by) : PackageContainerInterface((CacheSetHelper::PkgSelector)by) {}
APT_IGNORE_DEPRECATED_POP
	template<typename Itr> PackageContainer(Itr first, Itr last) : PackageContainerInterface(CacheSetHelper::UNKNOWN), _cont(first, last) {}
#if __cplusplus >= 201103L
	PackageContainer(std::initializer_list<value_type> list) : PackageContainerInterface(CacheSetHelper::UNKNOWN), _cont(list) {}
	void push_back(value_type&& P) { _cont.emplace_back(std::move(P)); }
	template<typename... Args> void emplace_back(Args&&... args) { _cont.emplace_back(std::forward<Args>(args)...); }
#endif
	void push_back(const value_type& P) { _cont.push_back(P); }

	/** \brief sort all included versions with given comparer

	    Some containers are sorted by default, some are not and can't be,
	    but a few like std::vector can be sorted if need be, so this can be
	    specialized in later on. The default is that this will fail though.
	    Specifically, already sorted containers like std::set will return
	    false as well as there is no easy way to check that the given comparer
	    would sort in the same way the set is currently sorted

	    \return \b true if the set was sorted, \b false if not. */
	template<class Compare> bool sort(Compare /*Comp*/) { return false; }

	/** \brief returns all packages in the cache who belong to the given task

	    A simple helper responsible for search for all members of a task
	    in the cache. Optional it prints a notice about the
	    packages chosen cause of the given task.
	    \param Cache the packages are in
	    \param pattern name of the task
	    \param helper responsible for error and message handling */
	static PackageContainer FromTask(pkgCacheFile &Cache, std::string const &pattern, CacheSetHelper &helper) {
		PackageContainer cont(CacheSetHelper::TASK);
		helper.PackageFrom(CacheSetHelper::TASK, &cont, Cache, pattern);
		return cont;
	}
	static PackageContainer FromTask(pkgCacheFile &Cache, std::string const &pattern) {
		CacheSetHelper helper;
		return FromTask(Cache, pattern, helper);
	}

	/** \brief returns all packages in the cache whose name matchs a given pattern

	    A simple helper responsible for executing a regular expression on all
	    package names in the cache. Optional it prints a notice about the
	    packages chosen cause of the given package.
	    \param Cache the packages are in
	    \param pattern regular expression for package names
	    \param helper responsible for error and message handling */
	static PackageContainer FromRegEx(pkgCacheFile &Cache, std::string const &pattern, CacheSetHelper &helper) {
		PackageContainer cont(CacheSetHelper::REGEX);
		helper.PackageFrom(CacheSetHelper::REGEX, &cont, Cache, pattern);
		return cont;
	}

	static PackageContainer FromRegEx(pkgCacheFile &Cache, std::string const &pattern) {
		CacheSetHelper helper;
		return FromRegEx(Cache, pattern, helper);
	}

	static PackageContainer FromFnmatch(pkgCacheFile &Cache, std::string const &pattern, CacheSetHelper &helper) {
		PackageContainer cont(CacheSetHelper::FNMATCH);
		helper.PackageFrom(CacheSetHelper::FNMATCH, &cont, Cache, pattern);
		return cont;
	}
	static PackageContainer FromFnMatch(pkgCacheFile &Cache, std::string const &pattern) {
		CacheSetHelper helper;
		return FromFnmatch(Cache, pattern, helper);
	}

APT_IGNORE_DEPRECATED_PUSH
	/** \brief returns a package specified by a string

	    \param Cache the package is in
	    \param pattern String the package name should be extracted from
	    \param helper responsible for error and message handling */
	APT_DEPRECATED_MSG("Use helper.PackageFromName instead") static pkgCache::PkgIterator FromName(pkgCacheFile &Cache, std::string const &pattern, CacheSetHelper &helper) {
		return helper.PackageFromName(Cache, pattern);
	}
	APT_DEPRECATED_MSG("Use helper.PackageFromName instead") static pkgCache::PkgIterator FromName(pkgCacheFile &Cache, std::string const &pattern) {
		CacheSetHelper helper;
		return FromName(Cache, pattern, helper);
	}
APT_IGNORE_DEPRECATED_POP

	/** \brief returns all packages specified by a string

	    \param Cache the packages are in
	    \param pattern String the package name(s) should be extracted from
	    \param helper responsible for error and message handling */
	static PackageContainer FromString(pkgCacheFile &Cache, std::string const &pattern, CacheSetHelper &helper) {
		PackageContainer cont;
		helper.PackageFrom(CacheSetHelper::PACKAGENAME, &cont, Cache, pattern);
		return cont;
	}
	static PackageContainer FromString(pkgCacheFile &Cache, std::string const &pattern) {
		CacheSetHelper helper;
		return FromString(Cache, pattern, helper);
	}

	/** \brief returns all packages specified on the commandline

	    Get all package names from the commandline and executes regex's if needed.
	    No special package command is supported, just plain names.
	    \param Cache the packages are in
	    \param cmdline Command line the package names should be extracted from
	    \param helper responsible for error and message handling */
	static PackageContainer FromCommandLine(pkgCacheFile &Cache, const char **cmdline, CacheSetHelper &helper) {
		PackageContainer cont;
		helper.PackageFromCommandLine(&cont, Cache, cmdline);
		return cont;
	}
	static PackageContainer FromCommandLine(pkgCacheFile &Cache, const char **cmdline) {
		CacheSetHelper helper;
		return FromCommandLine(Cache, cmdline, helper);