cf::WeakPtr¶

Non-owning weak reference for exclusively owned resources. More...

#include <weak_ptr.h>

Public Functions¶

	Name
constexpr	WeakPtr() =default Default constructor: creates an empty weak reference.
constexpr	WeakPtr(std::nullptr_t ) Constructs an empty weak reference from nullptr.
	WeakPtr(const WeakPtr & ) =default Copy constructor.
WeakPtr &	operator=(const WeakPtr & ) =default Copy assignment operator.
	WeakPtr(WeakPtr && ) =default Move constructor.
WeakPtr &	operator=(WeakPtr && ) =default Move assignment operator.
template <typenameU ,typename =std::enable_if_t>>	WeakPtr(const WeakPtr< U > & other) Covariant copy constructor from WeakPtr to WeakPtr.
template <typenameU ,typename =std::enable_if_t>> WeakPtr &	operator=(const WeakPtr< U > & other) Covariant copy assignment from WeakPtr to WeakPtr.
	~WeakPtr() =default Destructor: does not affect Owner lifetime.
T *	Get() const Gets the raw pointer if the owner is still alive.
T *	operator->() const Dereferences the weak pointer.
T &	operator*() const Dereferences the weak pointer.
bool	IsValid() const Checks if the owner is still alive.
	operator bool() const Boolean conversion operator for validity check.
void	Reset() Resets the weak pointer to empty state.
bool	operator==(const WeakPtr & other) const Equality comparison with another WeakPtr.
bool	operator!=(const WeakPtr & other) const Inequality comparison with another WeakPtr.
bool	operator==(std::nullptr_t ) const Equality comparison with nullptr.
bool	operator!=(std::nullptr_t ) const Inequality comparison with nullptr.
template <typenameSource > WeakPtr	DynamicCast(const WeakPtr< Source > & other) Dynamically converts WeakPtr to WeakPtr.

Friends¶

	Name
class	WeakPtr(WeakPtr ) Friend declaration for covariance support.
class	WeakPtrFactory(WeakPtrFactory ) Friend declaration for factory access.

Detailed Description¶

template <typenameT >
class cf::WeakPtr;

Non-owning weak reference for exclusively owned resources.

Template Parameters:

T Type of the referenced object.

Note: Supports covariance: WeakPtr can be implicitly converted to WeakPtr.

Warning: WeakPtr should only be used on the same thread (sequence) where it was created. The "check + dereference" two-step operation is not atomic.

Unlike std::weak_ptr, WeakPtr does not participate in reference counting. The resource is exclusively owned by an owner (typically holding WeakPtrFactory), and WeakPtr acts as a "claim ticket" that becomes invalid when the owner disappears.

class ThemeManager {
public:
    ...
private:
    WeakPtrFactory<ThemeManager> weak_factory_{this}; // Declare last
};

WeakPtr<ThemeManager> ref = tm.GetWeakPtr();
if (ref) {               // or ref.IsValid()
    ref->ApplyTheme();   // Safe access
}

Public Functions Documentation¶

function WeakPtr¶

constexpr WeakPtr() =default

Default constructor: creates an empty weak reference.

Exceptions:

None

Since: N/A

Note: None

Warning: None

function WeakPtr¶

inline constexpr WeakPtr(
    std::nullptr_t 
)

Constructs an empty weak reference from nullptr.

Parameters:

nullptr_t The nullptr literal.

Exceptions:

None

Since: N/A

Note: None

Warning: None

function WeakPtr¶

WeakPtr(
    constWeakPtr & 
) =default

Copy constructor.

Exceptions:

None

Since: N/A

Note: None

Warning: None

function operator=¶

WeakPtr & operator=(
    constWeakPtr & 
) =default

Copy assignment operator.

Parameters:

other Source weak pointer.

Exceptions:

None

Return: Reference to this WeakPtr.

Since: N/A

Note: None

Warning: None

function WeakPtr¶

WeakPtr(
    WeakPtr && 
) =default

Move constructor.

Exceptions:

None

Since: N/A

Note: None

Warning: None

function operator=¶

WeakPtr & operator=(
    WeakPtr && 
) =default

Move assignment operator.

Parameters:

other Source weak pointer.

Exceptions:

None

Return: Reference to this WeakPtr.

Since: N/A

Note: None

Warning: None

function WeakPtr¶

template <typenameU ,
typename  =std::enable_if_t<std::is_convertible_v<U*, T*>>>
inline WeakPtr(
    constWeakPtr< U > & other
)

Covariant copy constructor from WeakPtr to WeakPtr.

Parameters:

other Source weak pointer.

Exceptions:

None

Template Parameters:

U Derived type that is convertible to T.

Since: N/A

Note: None

Warning: None

function operator=¶

template <typenameU ,
typename  =std::enable_if_t<std::is_convertible_v<U*, T*>>>
inline WeakPtr & operator=(
    constWeakPtr< U > & other
)

Covariant copy assignment from WeakPtr to WeakPtr.

Parameters:

other Source weak pointer.

Exceptions:

None

Template Parameters:

U Derived type that is convertible to T.

Return: Reference to this WeakPtr.

Since: N/A

Note: None

Warning: None

function ~WeakPtr¶

~WeakPtr() =default

Destructor: does not affect Owner lifetime.

Exceptions:

None

Since: N/A

Note: None

Warning: None

function Get¶

inline T * Get() const

Gets the raw pointer if the owner is still alive.

Exceptions:

None

Return: Raw pointer to the owned object, or nullptr if owner is gone.

Since: N/A

Note: None

Warning: None

function operator->¶

inline T * operator->() const

Dereferences the weak pointer.

Exceptions:

None (assertion failure if invalid).

Return: Raw pointer to the owned object.

Since: N/A

Note: Asserts that the WeakPtr is valid before dereferencing.

Warning: Undefined behavior if called on an invalid WeakPtr.

function operator*¶

inline T & operator*() const

Dereferences the weak pointer.

Exceptions:

None (assertion failure if invalid).

Return: Reference to the owned object.

Since: N/A

Note: Asserts that the WeakPtr is valid before dereferencing.

Warning: Undefined behavior if called on an invalid WeakPtr.

function IsValid¶

inline bool IsValid() const

Checks if the owner is still alive.

Exceptions:

None

Return: true if the owner is alive, false otherwise.

Since: N/A

Note: None

Warning: None

function operator bool¶

inline explicit operator bool() const

Boolean conversion operator for validity check.

Exceptions:

None

Return: true if the owner is alive, false otherwise.

Since: N/A

Note: None

Warning: None

function Reset¶

inline void Reset()

Resets the weak pointer to empty state.

Exceptions:

None

Since: N/A

Note: After reset, IsValid() returns false.

Warning: None

function operator==¶

inline bool operator==(
    constWeakPtr & other
) const

Equality comparison with another WeakPtr.

Parameters:

other Other WeakPtr to compare with.

Exceptions:

None

Return: true if both weak pointers point to the same object.

Since: N/A

Note: None

Warning: None

function operator!=¶

inline bool operator!=(
    constWeakPtr & other
) const

Inequality comparison with another WeakPtr.

Parameters:

other Other WeakPtr to compare with.

Exceptions:

None

Return: true if weak pointers point to different objects.

Since: N/A

Note: None

Warning: None

function operator==¶

inline bool operator==(
    std::nullptr_t 
) const

Equality comparison with nullptr.

Exceptions:

None

Return: true if the WeakPtr is invalid (empty).

Since: N/A

Note: None

Warning: None

function operator!=¶

inline bool operator!=(
    std::nullptr_t 
) const

Inequality comparison with nullptr.

Exceptions:

None

Return: true if the WeakPtr is valid.

Since: N/A

Note: None

Warning: None

function DynamicCast¶

template <typenameSource >
static inline WeakPtr DynamicCast(
    constWeakPtr< Source > & other
)

Dynamically converts WeakPtr to WeakPtr.

Parameters:

other WeakPtr to the source object.

Exceptions:

None

Template Parameters:

Source Source type (base class).

Return: WeakPtr pointing to the same object if the object is of type Derived, otherwise invalid.

Since: N/A

Note: The returned WeakPtr shares the same weak reference flag as the source.

Warning: Always check the returned WeakPtr's validity before use.

Performs a dynamic_cast on the underlying pointer. Returns a valid WeakPtr if the cast succeeds, otherwise returns an invalid WeakPtr.

WeakPtr<BaseClass> basePtr = ...;
auto derivedPtr = WeakPtr<DerivedClass>::DynamicCast(basePtr);
if (derivedPtr) {
    derivedPtr->DerivedMethod();
}

Friends¶

friend WeakPtr¶

friend class WeakPtr(
    WeakPtr 
);

Friend declaration for covariance support.

Template Parameters:

U Type parameter for the befriended WeakPtr.

Since: N/A

friend WeakPtrFactory¶

friend class WeakPtrFactory(
    WeakPtrFactory 
);

Friend declaration for factory access.

Template Parameters:

U Type parameter for the befriended WeakPtrFactory.

Since: N/A

Updated on 2026-03-09 at 10:14:00 +0000