Singleton

#include <icy/singleton.h>

Helper template class for managing singleton objects allocated on the heap.

Public Methods

Return	Name	Description
	`Singleton`	Defaulted constructor.
`S *`	`get` `inline`	Returns a pointer to the managed singleton, instantiating it on first call. Thread-safe; protected by an internal mutex.
`S *`	`swap` `inline`	Replaces the managed singleton with newPtr and returns the previous instance. The caller takes ownership of the returned pointer. Thread-safe; protected by an internal mutex.
`void`	`destroy` `inline`	Destroys the managed singleton instance and resets the internal pointer to null. Thread-safe; protected by an internal mutex.

Singleton

Singleton() = default

Defaulted constructor.

get

inline

inline S * get()

Returns a pointer to the managed singleton, instantiating it on first call. Thread-safe; protected by an internal mutex.

Returns

Pointer to the singleton instance (never null).

swap

inline

inline S * swap(S * newPtr)

Replaces the managed singleton with newPtr and returns the previous instance. The caller takes ownership of the returned pointer. Thread-safe; protected by an internal mutex.

Parameters

newPtr Replacement instance (may be nullptr).

Returns

Previously managed pointer (caller must delete if non-null).

destroy

inline

inline void destroy()

Destroys the managed singleton instance and resets the internal pointer to null. Thread-safe; protected by an internal mutex.

Private Attributes

Return	Name	Description
`std::unique_ptr< S, Deleter >`	`_ptr`
`std::mutex`	`_m`

_ptr

std::unique_ptr< S, Deleter > _ptr

_m

std::mutex _m