x::singletonptr< ref_type, baseClass > Class Template Reference

A singleton reference. More...

#include <singletonptr.H>

Public Member Functions
	singletonptr ()
	Default constructor.
	singletonptr (const ptr< ref_type, baseClass > &p)
	Explicit constructor.
	~singletonptr ()
	Destructor.
Public Member Functions inherited from x::ptr< objClass, baseClass >
	ptr () noexcept LIBCXX_INLINE
	Default constructor.
	ptr (const ptr< objClass, baseClass > &o) noexcept LIBCXX_INLINE
	Copy constructor.
template<typename objClass2 , typename baseClass2 >
	ptr (const ptr< objClass2, baseClass2 > &o) LIBCXX_INLINE
	Construct from a reference to a subclass or a superclass.
template<typename baseClass2 >
	ptr (const ref< objClass, baseClass2 > &o) noexcept
	Copy constructor.
	ptr (objClass *pArg) noexcept LIBCXX_INLINE
	The default constructor from this.
	ptr (ptr< objClass, baseClass > &&o) noexcept LIBCXX_INLINE
	Move constructor.
template<typename objClass2 , typename baseClass2 >
	ptr (ptr< objClass2, baseClass2 > &&o) LIBCXX_INLINE
	Move constructor from a subclass or a superclass.
template<typename baseClass2 >
	ptr (ref< objClass, baseClass2 > &&o) noexcept
	Move constructor.
	~ptr () LIBCXX_INLINE
	The default destructor.
objClass &	operator* () const LIBCXX_INLINE
	Implement the "*" operator for object references.
objClass *	operator-> () const LIBCXX_INLINE
	Implement the "->" operator for object references.
ptr< objClass, baseClass > &	operator= (const ptr< objClass, baseClass > &o) noexcept LIBCXX_INLINE
	The assignment operator.
template<typename objClass2 , typename baseClass2 >
ptr< objClass, baseClass > &	operator= (const ptr< objClass2, baseClass2 > &o)
	Convert from a reference to a different type.
template<typename objClass2 >
ptr< objClass, baseClass > &	operator= (objClass2 *o)
	Convert from a reference to a different type.
ptr< objClass, baseClass > &	operator= (ptr< objClass, baseClass > &&o) noexcept LIBCXX_INLINE
	The move operator.
template<typename objClass2 , typename baseClass2 >
ptr< objClass, baseClass > &	operator= (ptr< objClass2, baseClass2 > &&o)
	Move from a reference to a different type.
ptr< objClass, baseClass > &	operator= (std::nullptr_t) LIBCXX_INLINE
	Convert from a nullptr.
auto	weaken () const
	Make a weak pointer out of me.
Public Member Functions inherited from x::const_ptr< objClass, baseClass >
	const_ptr () noexcept LIBCXX_INLINE
template<typename baseClass2 >
	const_ptr (const const_ref< objClass, baseClass2 > &o) noexcept
	Copy constructor.
	const_ptr (const objClass *pArg) noexcept LIBCXX_INLINE
	const_ptr (const ptrImpl< objClass > &o) noexcept LIBCXX_INLINE
	Copy constructor.
template<typename objClass2 >
	const_ptr (const ptrImpl< objClass2 > &o)
template<typename baseClass2 >
	const_ptr (const ref< objClass, baseClass2 > &o) noexcept
	Copy constructor called by const_ref.
template<typename baseClass2 >
	const_ptr (const_ptr< objClass, baseClass2 > &&o) noexcept
template<typename baseClass2 >
	const_ptr (const_ref< objClass, baseClass2 > &&o) noexcept
	Move constructor.
template<typename baseClass2 >
	const_ptr (ptr< objClass, baseClass2 > &&o) noexcept
template<typename baseClass2 >
	const_ptr (ref< objClass, baseClass2 > &&o) noexcept
	Move constructor called by const_ref.
	~const_ptr () LIBCXX_INLINE
	The default destructor.
const objClass &	operator* () const LIBCXX_INLINE
	Implement the "*" operator for pointer references.
const objClass *	operator-> () const LIBCXX_INLINE
	Implement the "->" operator for pointer references.
template<typename T > requires is_derived_from_ref_or_ptr<T>
std::strong_ordering	operator<=> (const T &o) const noexcept LIBCXX_INLINE
	Comparison operator.
template<typename objClass2 >
const_ptr< objClass, baseClass > &	operator= (const objClass2 *o)
const_ptr< objClass, baseClass > &	operator= (const ptrImpl< objClass > &o) noexcept
	The assignment operator.
template<typename objClass2 >
const_ptr< objClass, baseClass > &	operator= (const ptrImpl< objClass2 > &o)
	Convert from a pointer reference to a different type.
const_ptr< objClass, baseClass > &	operator= (ptrImpl< objClass > &&o) noexcept LIBCXX_INLINE
	The move operator.
template<typename T > requires is_derived_from_ref_or_ptr<T>
bool	operator== (const T &o) const noexcept LIBCXX_INLINE
Public Member Functions inherited from x::ptrImpl< objClass >
template<typename baseClass > requires derived_from_obj<objClass>
	ptrImpl (const const_ref< objClass, baseClass > &o) noexcept
	ptrImpl (const ptrImpl< objClass > &o) noexcept LIBCXX_INLINE
	The default copy constructor.
template<typename baseClass > requires derived_from_obj<objClass>
	ptrImpl (const ref< objClass, baseClass > &o) noexcept
template<typename baseClass > requires derived_from_obj<objClass>
	ptrImpl (const_ptr< objClass, baseClass > &&o) noexcept
	Move constructor.
template<typename baseClass > requires derived_from_obj<objClass>
	ptrImpl (const_ref< objClass, baseClass > &&o) noexcept
template<typename impl_objClass = objClass> requires derived_from_obj<impl_objClass>
	ptrImpl (objClass *pArg) noexcept LIBCXX_INLINE
	Default constructor.
template<typename baseClass > requires derived_from_obj<objClass>
	ptrImpl (ptr< objClass, baseClass > &&o) noexcept
	Move constructor.
	ptrImpl (ptrImpl< objClass > &&o) noexcept LIBCXX_INLINE
	Move constructor.
template<typename baseClass > requires derived_from_obj<objClass>
	ptrImpl (ref< objClass, baseClass > &&o) noexcept
	~ptrImpl () LIBCXX_INLINE
	Default destructor.
bool	null () const noexcept LIBCXX_INLINE
	Check if this is an unbound reference.
	operator bool () const noexcept
	Make it work in boolean context.
bool	operator! () const noexcept
	Make it work in boolean context.
ptrImpl< objClass > &	operator= (const ptrImpl< objClass > &o) noexcept LIBCXX_INLINE
	The default assignment operator.
ptrImpl< objClass > &	operator= (ptrImpl< objClass > &&o) noexcept LIBCXX_INLINE
	The move operator.

Static Private Member Functions
static pthread_mutex_t &	get_instance_mutex ()
	The global instance.
static ref_type *&	get_object ()

Private Attributes
bool	initial
	Whether this is the initial one.

Additional Inherited Members
Public Types inherited from x::ptr< objClass, baseClass >
typedef std_refptr_traits< objClass, baseClass, ptr< objClass, baseClass > >	traits_t
	Our traits.
Public Types inherited from x::const_ptr< objClass, baseClass >
typedef baseClass	base
	Provide for this pointer's base class.
typedef objClass	obj_type
	Define this pointer's object class.
typedef std_refptr_traits< objClass, baseClass, const_ptr< objClass, baseClass > >	traits_t
	Our traits.
Public Types inherited from x::ptrImpl< objClass >
typedef objClass	obj_type
	Define this reference's base type.
Static Public Member Functions inherited from x::ptr< objClass, baseClass >
template<typename... Args_t>
static auto	create (Args_t &&...args) LIBCXX_INLINE
	Forward create() to the base type.
Static Public Member Functions inherited from x::const_ptr< objClass, baseClass >
template<typename... Args_t>
static auto	create (Args_t &&...args) LIBCXX_INLINE
	Forward create() to the base type.
Protected Member Functions inherited from x::ptrImpl< objClass >
objClass *	getrefP () const noexcept LIBCXX_INLINE
	Return the underlying pointer.
void	setRef (objClass *newRefP) noexcept LIBCXX_INLINE
	Update reference pointer.
void	setRef_noconscheck (objClass *newRefP) noexcept LIBCXX_INLINE
	Update reference pointer.
Protected Attributes inherited from x::ptrImpl< objClass >
objClass *	refP
	Object that this reference is bound to.

Detailed Description

template<typename ref_type, typename baseClass = ptrref_base>
class x::singletonptr< ref_type, baseClass >

A singleton reference.

class global_dataObj : virtual public LIBCXX_NAMESPACE::obj {
};
 
typedef singletonptr<global_dataObj> global_data_t;
 
// ...
 
int main()
{
     global_data_t global_data{ ref<global_dataObj>::create() };
 
     // ...
}
 
// ...
 
if (foo())
{
    global_data_t global_data;
 
    if (global_data)
    {
          global_data->method();
    }
}

A singletonptr wraps a global reference to an object. Instances of singletonptr should always be constructed in automatic scope.

Passing a ref to an existing object to singletonptr's constructor makes the object available to any other instances of default-constructed singletonptr. The referenced object remains available until all instances of singletonptr go out of their automatic scope.

A singletonptr is a subclass of a ptr. The default constructor results in a null ptr if no other existing instance of a singleton exists which was constructed with an explicit object.

Constructor & Destructor Documentation

singletonptr() [1/2]

template<typename ref_type , typename baseClass = ptrref_base>

x::singletonptr< ref_type, baseClass >::singletonptr ( const ptr< ref_type, baseClass > &  p )

inline

Explicit constructor.

singletonptr() [2/2]

template<typename ref_type , typename baseClass = ptrref_base>

x::singletonptr< ref_type, baseClass >::singletonptr ( )

inline

Default constructor.

~singletonptr()

template<typename ref_type , typename baseClass = ptrref_base>

x::singletonptr< ref_type, baseClass >::~singletonptr ( )

inline

Destructor.

Member Function Documentation

get_instance_mutex()

template<typename ref_type , typename baseClass = ptrref_base>

static pthread_mutex_t & x::singletonptr< ref_type, baseClass >::get_instance_mutex ( )

inlinestaticprivate

The global instance.

Reverting to pthread_mutex_t, since there is no guarantee that std::mutex is trivially destructible, and the singleton can be in static scope, and global destruction phase can begin while some thread is still in its death throes.

get_object()

template<typename ref_type , typename baseClass = ptrref_base>

static ref_type *& x::singletonptr< ref_type, baseClass >::get_object ( )

inlinestaticprivate

Member Data Documentation

initial

template<typename ref_type , typename baseClass = ptrref_base>

bool x::singletonptr< ref_type, baseClass >::initial

private

Whether this is the initial one.

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

• includes/x/singletonptr.H