Reference counted access to a Tp object calling a custom Dispose function when the last AutoDispose handle to it is destroyed or reset. More...

#include <zypp-core/AutoDispose.h>

Inheritance diagram for zypp::AutoDispose< Tp >:

[legend]

Classes
struct	Impl

Public Types
using	param_type = typename boost::call_traits<Tp>::param_type
using	reference = typename boost::call_traits<Tp>::reference
using	const_reference = typename boost::call_traits<Tp>::const_reference
using	value_type = Tp
using	result_type = typename boost::call_traits<Tp>::value_type
using	dispose_param_type = std::conditional_t< std::is_pointer_v<Tp> \|\| std::is_integral_v<Tp>, Tp const, reference >
using	Dispose = function<void ( dispose_param_type )>
	Dispose function signatue.

Public Member Functions
	AutoDispose ()
	Default Ctor using default constructed value and no dispose function.
	AutoDispose (Dispose dispose_r)
	Ctor taking dispose function and using default constructed value.
	AutoDispose (value_type value_r)
	Ctor taking value and no dispose function.
	AutoDispose (value_type value_r, Dispose dispose_r)
	Ctor taking value and dispose function.
	operator reference () const
	Provide implicit conversion to `Tp&`.
reference	value () const
	Reference to the `Tp` object.
reference	operator* () const
	Reference to the `Tp` object.
value_type *	operator-> () const
	Pointer to the `Tp` object (asserted to be != NULL).
void	reset ()
	Reset to default Ctor values.
void	swap (AutoDispose &rhs) noexcept
	Exchange the contents of two AutoDispose objects.
bool	unique () const
	Returns true if this is the only AutoDispose instance managing the current data object.
const Dispose &	getDispose () const
	Return the current dispose function.
void	setDispose (const Dispose &dispose_r)
	Set a new dispose function.
void	resetDispose ()
	Set no dispose function.
void	swapDispose (Dispose &dispose_r)
	Exchange the dispose function.

Private Attributes
shared_ptr< Impl >	_pimpl

Related Symbols
(Note that these are not member symbols.)
template<class Tp>
std::ostream &	operator<< (std::ostream &str, const AutoDispose< Tp > &obj)
	Stream output of the `Tp` object.

Detailed Description

template<class Tp>
class zypp::AutoDispose< Tp >

Reference counted access to a Tp object calling a custom Dispose function when the last AutoDispose handle to it is destroyed or reset.

Note: As with pointers, constness of an AutoDispose object does not apply to the stored Tp object. If the stored Tp object should be immutable, you should use AutoDispose<const Tp>.

Pass a filename to the application and provide the appropriate code to be executed when the file is no longer needed:

struct FileCache
{
  Pathname getFile();
  void     releaseFile( const Pathname & );
};
 
static FileCache cache;
 
void unlink( const Pathname & file_r );
 
AutoDispose<const Pathname> provideFile( ... )
{
  if ( file_is_in_cache )
    {
      // will call 'cache.releaseFile( file )'
      return AutoDispose<const Pathname>( cache.getFile(),
                                          bind( &FileCache::releaseFile, ref(cache), _1 ) );
    }
  else if ( file_is_temporary )
    {
      // will call 'unlink( file )'
      return AutoDispose<const Pathname>( file, unlink );
    }
  else if ( file_is_permanent )
    {
      // will do nothing.
      return AutoDispose<const Pathname>( file );
    }
  else
    {
      // will do nothing.
      return AutoDispose<const Pathname>();
    }
}

Exception safe handling of temporary files:

void provideFileAt( const Pathname & destination )
{
  AutoDispose<const Pathname> guard( destination, unlink );
 
  // Any exception here will lead to 'unlink( destination )'
  // ...
 
  // On success: reset the dispose function to NOOP.
  guard.resetDispose();
}

Definition at line 94 of file AutoDispose.h.

Member Typedef Documentation

◆ param_type

template<class Tp>

using zypp::AutoDispose< Tp >::param_type = typename boost::call_traits<Tp>::param_type

Definition at line 97 of file AutoDispose.h.

◆ reference

template<class Tp>

using zypp::AutoDispose< Tp >::reference = typename boost::call_traits<Tp>::reference

Definition at line 98 of file AutoDispose.h.

◆ const_reference

template<class Tp>

using zypp::AutoDispose< Tp >::const_reference = typename boost::call_traits<Tp>::const_reference

Definition at line 99 of file AutoDispose.h.

◆ value_type

template<class Tp>

using zypp::AutoDispose< Tp >::value_type = Tp

Definition at line 100 of file AutoDispose.h.

◆ result_type

template<class Tp>

using zypp::AutoDispose< Tp >::result_type = typename boost::call_traits<Tp>::value_type

Definition at line 101 of file AutoDispose.h.

◆ dispose_param_type

template<class Tp>

using zypp::AutoDispose< Tp >::dispose_param_type = std::conditional_t< std::is_pointer_v<Tp> || std::is_integral_v<Tp>, Tp const, reference >

Definition at line 104 of file AutoDispose.h.

◆ Dispose

template<class Tp>

using zypp::AutoDispose< Tp >::Dispose = function<void ( dispose_param_type )>

Dispose function signatue.

Definition at line 108 of file AutoDispose.h.

Constructor & Destructor Documentation

◆ AutoDispose() [1/4]

template<class Tp>

zypp::AutoDispose< Tp >::AutoDispose ( )

inline

Default Ctor using default constructed value and no dispose function.

Definition at line 112 of file AutoDispose.h.

◆ AutoDispose() [2/4]

template<class Tp>

zypp::AutoDispose< Tp >::AutoDispose ( Dispose dispose_r )

inlineexplicit

Ctor taking dispose function and using default constructed value.

Definition at line 117 of file AutoDispose.h.

◆ AutoDispose() [3/4]

template<class Tp>

zypp::AutoDispose< Tp >::AutoDispose ( value_type value_r )

inlineexplicit

Ctor taking value and no dispose function.

Definition at line 122 of file AutoDispose.h.

◆ AutoDispose() [4/4]

template<class Tp>

zypp::AutoDispose< Tp >::AutoDispose	(	value_type	value_r,
		Dispose	dispose_r )

inline

Ctor taking value and dispose function.

Definition at line 127 of file AutoDispose.h.

Member Function Documentation

◆ operator reference()

template<class Tp>

zypp::AutoDispose< Tp >::operator reference ( ) const

inline

Provide implicit conversion to Tp&.

Definition at line 134 of file AutoDispose.h.

◆ value()

template<class Tp>

reference zypp::AutoDispose< Tp >::value ( ) const

inline

Reference to the Tp object.

Definition at line 138 of file AutoDispose.h.

◆ operator*()

template<class Tp>

reference zypp::AutoDispose< Tp >::operator* ( ) const

inline

Reference to the Tp object.

Definition at line 142 of file AutoDispose.h.

◆ operator->()

template<class Tp>

value_type * zypp::AutoDispose< Tp >::operator-> ( ) const

inline

Pointer to the Tp object (asserted to be != NULL).

Definition at line 146 of file AutoDispose.h.

◆ reset()

template<class Tp>

void zypp::AutoDispose< Tp >::reset ( )

inline

Reset to default Ctor values.

Definition at line 150 of file AutoDispose.h.

◆ swap()

template<class Tp>

void zypp::AutoDispose< Tp >::swap ( AutoDispose< Tp > & rhs )

inlinenoexcept

Exchange the contents of two AutoDispose objects.

Definition at line 154 of file AutoDispose.h.

◆ unique()

template<class Tp>

bool zypp::AutoDispose< Tp >::unique ( ) const

inline

Returns true if this is the only AutoDispose instance managing the current data object.

Definition at line 158 of file AutoDispose.h.

◆ getDispose()

template<class Tp>

const Dispose & zypp::AutoDispose< Tp >::getDispose ( ) const

inline

Return the current dispose function.

Definition at line 163 of file AutoDispose.h.

◆ setDispose()

template<class Tp>

void zypp::AutoDispose< Tp >::setDispose ( const Dispose & dispose_r )

inline

Set a new dispose function.

Definition at line 167 of file AutoDispose.h.

◆ resetDispose()

template<class Tp>

void zypp::AutoDispose< Tp >::resetDispose ( )

inline

Set no dispose function.

Definition at line 171 of file AutoDispose.h.

◆ swapDispose()

template<class Tp>

void zypp::AutoDispose< Tp >::swapDispose ( Dispose & dispose_r )

inline

Exchange the dispose function.

Definition at line 175 of file AutoDispose.h.

◆ operator<<()

template<class Tp>

std::ostream & operator<<	(	std::ostream &	str,
		const AutoDispose< Tp > &	obj )

Stream output of the Tp object.

Definition at line 300 of file AutoDispose.h.

Member Data Documentation

◆ _pimpl

template<class Tp>

shared_ptr<Impl> zypp::AutoDispose< Tp >::_pimpl

private

Definition at line 199 of file AutoDispose.h.

The documentation for this class was generated from the following file:

zypp-core/AutoDispose.h

Classes

Public Types

Public Member Functions

Private Attributes

Related Symbols

Detailed Description

Member Typedef Documentation

◆ param_type

◆ reference

◆ const_reference

◆ value_type

◆ result_type

◆ dispose_param_type

◆ Dispose

Constructor & Destructor Documentation

◆ AutoDispose() [1/4]

◆ AutoDispose() [2/4]

◆ AutoDispose() [3/4]

◆ AutoDispose() [4/4]

Member Function Documentation

◆ operator reference()

◆ value()

◆ operator*()

◆ operator->()

◆ reset()

◆ swap()

◆ unique()

◆ getDispose()

◆ setDispose()

◆ resetDispose()

◆ swapDispose()

Friends And Related Symbol Documentation

◆ operator<<()

Member Data Documentation

◆ _pimpl