zth::Singleton< T > Class Template Reference

Singleton pattern. More...

#include <util.h>

Public Types
typedef T	singleton_type
	Alias of the T template parameter.

Static Public Member Functions
static constexpr safe_ptr< singleton_type >::type	instance () noexcept
	Return the only instance of T.

Protected Member Functions
constexpr	Singleton () noexcept
	Constructor.
	~Singleton ()
	Destructor.

Detailed Description

template<typename T>
class zth::Singleton< T >

Singleton pattern.

When a class inherits this class, the single instance of that class is available via the static instance() function.

A class should use Singleton as follows:

class Subclass : public Singleton<Subclass>
{
public:
  Subclass() {} // no need to invoke Singleton()
  // ...normal class implementation
};

Make sure that the template parameter T is the same as the subclass.

Template Parameters

T	the type of the subclass that inherits this Singleton.

Definition at line 1088 of file util.h.

Member Typedef Documentation

singleton_type

template<typename T >

typedef T zth::Singleton< T >::singleton_type

Alias of the T template parameter.

Definition at line 1091 of file util.h.

Constructor & Destructor Documentation

Singleton()

template<typename T >

constexpr zth::Singleton< T >::Singleton ( )

inlineconstexprprotectednoexcept

Constructor.

(Only) the first instance of the T is recorded in m_instance.

Definition at line 1098 of file util.h.

~Singleton()

template<typename T >

zth::Singleton< T >::~Singleton ( )

inlineprotected

Destructor.

After destruction, instance() will return nullptr.

Definition at line 1111 of file util.h.

Member Function Documentation

instance()

template<typename T >

static constexpr safe_ptr< singleton_type >::type zth::Singleton< T >::instance ( )

inlinestaticconstexprnoexcept

Return the only instance of T.

Returns

the instance, or nullptr when not constructed yet/anymore.

Definition at line 1123 of file util.h.

---

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

• include/libzth/util.h