boost::attributes::mutable_constant< T, MutexT, ScopedWriteLockT, ScopedReadLockT > Class Template Reference

A class of an attribute that holds a single constant value with ability to change it. More...

#include <mutable_constant.hpp>

Inheritance diagram for boost::attributes::mutable_constant< T, MutexT, ScopedWriteLockT, ScopedReadLockT >:

Collaboration diagram for boost::attributes::mutable_constant< T, MutexT, ScopedWriteLockT, ScopedReadLockT >:

Classes
class	impl
	Factory implementation. More...

Public Types
typedef T	value_type
	The attribute value type. More...

Public Member Functions
	mutable_constant (value_type const &value)
	Constructor with the stored value initialization. More...
	mutable_constant (BOOST_RV_REF(value_type) value)
	Constructor with the stored value initialization. More...
	mutable_constant (cast_source const &source)
	Constructor for casting support. More...
void	set (value_type const &value)
	The method sets a new attribute value. More...
void	set (BOOST_RV_REF(value_type) value)
	The method sets a new attribute value. More...
value_type	get () const
	The method acquires the current attribute value. More...
bool	operator! () const BOOST_NOEXCEPT
	Verifies that the factory is not in empty state. More...
attribute_value	get_value () const
void	swap (attribute &that) BOOST_NOEXCEPT
	The method swaps two factories (i.e. More...

Protected Member Functions
impl *	get_impl () const
void	set_impl (intrusive_ptr< impl > p) BOOST_NOEXCEPT
	Sets the pointer to the factory implementation. More...

Detailed Description

template<typename T, typename MutexT = void, typename ScopedWriteLockT = typename mpl::if_c< boost::log::aux::is_exclusively_lockable< MutexT >::value, boost::log::aux::exclusive_lock_guard< MutexT >, void >::type, typename ScopedReadLockT = typename mpl::if_c< boost::log::aux::is_shared_lockable< MutexT >::value, boost::log::aux::shared_lock_guard< MutexT >, ScopedWriteLockT >::type>
class boost::attributes::mutable_constant< T, MutexT, ScopedWriteLockT, ScopedReadLockT >

A class of an attribute that holds a single constant value with ability to change it.

The mutable_constant attribute stores a single value of type, specified as the first template argument. This value is returned on each attribute value acquisition.

The attribute also allows to modify the stored value, even if the attribute is registered in an attribute set. In order to ensure thread safety of such modifications the mutable_constant class is also parametrized with three additional template arguments: mutex type, scoped write and scoped read lock types. If not specified, the lock types are automatically deduced based on the mutex type.

The implementation may avoid using these types to actually create and use the mutex, if a more efficient synchronization method is available (such as atomic operations on the value type). By default no synchronization is done.

Member Typedef Documentation

template<typename T, typename MutexT = void, typename ScopedWriteLockT = typename mpl::if_c< boost::log::aux::is_exclusively_lockable< MutexT >::value, boost::log::aux::exclusive_lock_guard< MutexT >, void >::type, typename ScopedReadLockT = typename mpl::if_c< boost::log::aux::is_shared_lockable< MutexT >::value, boost::log::aux::shared_lock_guard< MutexT >, ScopedWriteLockT >::type>

typedef T boost::attributes::mutable_constant< T, MutexT, ScopedWriteLockT, ScopedReadLockT >::value_type

The attribute value type.

Constructor & Destructor Documentation

template<typename T, typename MutexT = void, typename ScopedWriteLockT = typename mpl::if_c< boost::log::aux::is_exclusively_lockable< MutexT >::value, boost::log::aux::exclusive_lock_guard< MutexT >, void >::type, typename ScopedReadLockT = typename mpl::if_c< boost::log::aux::is_shared_lockable< MutexT >::value, boost::log::aux::shared_lock_guard< MutexT >, ScopedWriteLockT >::type>

boost::attributes::mutable_constant< T, MutexT, ScopedWriteLockT, ScopedReadLockT >::mutable_constant ( value_type const &  value )

inlineexplicit

Constructor with the stored value initialization.

template<typename T, typename MutexT = void, typename ScopedWriteLockT = typename mpl::if_c< boost::log::aux::is_exclusively_lockable< MutexT >::value, boost::log::aux::exclusive_lock_guard< MutexT >, void >::type, typename ScopedReadLockT = typename mpl::if_c< boost::log::aux::is_shared_lockable< MutexT >::value, boost::log::aux::shared_lock_guard< MutexT >, ScopedWriteLockT >::type>

boost::attributes::mutable_constant< T, MutexT, ScopedWriteLockT, ScopedReadLockT >::mutable_constant ( BOOST_RV_REF(value_type)  value )

inlineexplicit

Constructor with the stored value initialization.

template<typename T, typename MutexT = void, typename ScopedWriteLockT = typename mpl::if_c< boost::log::aux::is_exclusively_lockable< MutexT >::value, boost::log::aux::exclusive_lock_guard< MutexT >, void >::type, typename ScopedReadLockT = typename mpl::if_c< boost::log::aux::is_shared_lockable< MutexT >::value, boost::log::aux::shared_lock_guard< MutexT >, ScopedWriteLockT >::type>

boost::attributes::mutable_constant< T, MutexT, ScopedWriteLockT, ScopedReadLockT >::mutable_constant ( cast_source const &  source )

inlineexplicit

Constructor for casting support.

Member Function Documentation

template<typename T, typename MutexT = void, typename ScopedWriteLockT = typename mpl::if_c< boost::log::aux::is_exclusively_lockable< MutexT >::value, boost::log::aux::exclusive_lock_guard< MutexT >, void >::type, typename ScopedReadLockT = typename mpl::if_c< boost::log::aux::is_shared_lockable< MutexT >::value, boost::log::aux::shared_lock_guard< MutexT >, ScopedWriteLockT >::type>

value_type boost::attributes::mutable_constant< T, MutexT, ScopedWriteLockT, ScopedReadLockT >::get ( ) const

inline

The method acquires the current attribute value.

The implementation non-exclusively locks the mutex in order to protect the value acquisition.

template<typename T, typename MutexT = void, typename ScopedWriteLockT = typename mpl::if_c< boost::log::aux::is_exclusively_lockable< MutexT >::value, boost::log::aux::exclusive_lock_guard< MutexT >, void >::type, typename ScopedReadLockT = typename mpl::if_c< boost::log::aux::is_shared_lockable< MutexT >::value, boost::log::aux::shared_lock_guard< MutexT >, ScopedWriteLockT >::type>

impl* boost::attributes::mutable_constant< T, MutexT, ScopedWriteLockT, ScopedReadLockT >::get_impl ( ) const

inlineprotected

Returns

Pointer to the factory implementation

Referenced by boost::attributes::mutable_constant< channel_type >::get(), boost::attributes::mutable_constant< T, void, void, void >::get(), boost::attributes::mutable_constant< channel_type >::set(), and boost::attributes::mutable_constant< T, void, void, void >::set().

attribute_value boost::attribute::get_value ( ) const

inherited

Returns

The actual attribute value. It shall not return empty values (exceptions shall be used to indicate errors).

bool boost::attribute::operator! ( ) const

inlineinherited

Verifies that the factory is not in empty state.

Verifies that the factory is in empty state

template<typename T, typename MutexT = void, typename ScopedWriteLockT = typename mpl::if_c< boost::log::aux::is_exclusively_lockable< MutexT >::value, boost::log::aux::exclusive_lock_guard< MutexT >, void >::type, typename ScopedReadLockT = typename mpl::if_c< boost::log::aux::is_shared_lockable< MutexT >::value, boost::log::aux::shared_lock_guard< MutexT >, ScopedWriteLockT >::type>

void boost::attributes::mutable_constant< T, MutexT, ScopedWriteLockT, ScopedReadLockT >::set ( value_type const &  value )

inline

The method sets a new attribute value.

The implementation exclusively locks the mutex in order to protect the value assignment.

template<typename T, typename MutexT = void, typename ScopedWriteLockT = typename mpl::if_c< boost::log::aux::is_exclusively_lockable< MutexT >::value, boost::log::aux::exclusive_lock_guard< MutexT >, void >::type, typename ScopedReadLockT = typename mpl::if_c< boost::log::aux::is_shared_lockable< MutexT >::value, boost::log::aux::shared_lock_guard< MutexT >, ScopedWriteLockT >::type>

void boost::attributes::mutable_constant< T, MutexT, ScopedWriteLockT, ScopedReadLockT >::set ( BOOST_RV_REF(value_type)  value )

inline

The method sets a new attribute value.

void boost::attribute::set_impl ( intrusive_ptr< impl >  p )

inlineprotectedinherited

Sets the pointer to the factory implementation.

Parameters

p	Pointer to the implementation. Must not be NULL.

References boost::multiprecision::backends::p, and boost::intrusive_ptr< T >::swap().

Referenced by boost::attributes::counter< T >::counter().

void boost::attribute::swap ( attribute &  that )

inlineinherited

The method swaps two factories (i.e.

their implementations).

References boost::intrusive_ptr< T >::swap().

Referenced by boost::sources::aux::severity_level< severity_level >::operator=(), and boost::sources::basic_severity_logger< BaseT, LevelT >::swap_unlocked().

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

• boost_1_57_0/boost/log/attributes/mutable_constant.hpp