carb::extras::ConstHandleRef

Defined in carb/extras/HandleDatabase.h

template<class Mapped, class Handle, class Allocator = std::allocator<Mapped>> struct ConstHandleRef

A smart-reference class for a Handle associated with a HandleDatabase.

When HandleRef is destroyed, the associated handle is released with the HandleDatabase.

Subclassed by carb::extras::HandleRef< Mapped, Handle, Allocator >

Public Types

using MappedType = const Mapped : An alias to Mapped; the mapped value type.

using ReferenceType = const Mapped&: An alias to const Mapped&.

using PointerType = const Mapped*: An alias to const Mapped*.

using HandleType = Handle : An alias to Handle; the key type used to associate a mapped value type.

using AllocatorType = Allocator : An alias to Allocator; the allocator used to allocate memory.

using Database = HandleDatabase<Mapped, Handle, Allocator>: The type specification for the associated HandleDatabase.

using element_type = MappedType : Deprecated: Use MappedType instead.

using handle_type = HandleType : Deprecated: Use HandleType instead.

Public Functions

ConstHandleRef() = default

Default constructor.

Produces an empty HandleRef.

inline ConstHandleRef(Database &database, Handle handle) noexcept

Attempts to atomically reference a Handle from the given database.

Parameters

database – The HandleDatabase containing handle.
handle – The handle previously returned from HandleDatabase::createHandle(). Providing an invalid or previously-valid handle results in an empty HandleRef.

inline ~ConstHandleRef() noexcept

Destructor.

If *this is non-empty, releases the associated Handle with the associated HandleDatabase.

inline ConstHandleRef(ConstHandleRef &&other) noexcept

Move-constructor.

Post-condition: other is an empty HandleRef.

Parameters: other – The other HandleRef to move a reference from.

inline ConstHandleRef &operator=(ConstHandleRef &&other) noexcept

Move-assign operator.

Swaps state with other.

Parameters: other – The other HandleRef to move a reference from.

inline ConstHandleRef clone() const noexcept

Explicitly adds a reference to any referenced handle and returns a HandleRef.

Returns: A HandleRef holding its own reference for the contained handle. May be empty if *this is empty.

inline PointerType operator->() noexcept

Dereferences and returns a pointer to the mapped type.

Warning

Undefined behavior if *this is empty.

Returns: A pointer to the mapped type.

inline PointerType operator->() const noexcept

Dereferences and returns a const pointer to the mapped type.

Warning

Undefined behavior if *this is empty.

Returns: A const pointer to the mapped type.

inline ReferenceType operator*() noexcept

Dereferences and returns a reference to the mapped type.

Warning

Undefined behavior if *this is empty.

Returns: A reference to the mapped type.

inline ReferenceType operator*() const noexcept

Dereferences and returns a const reference to the mapped type.

Warning

Undefined behavior if *this is empty.

Returns: A const reference to the mapped type.

inline PointerType get() noexcept

Returns a pointer to the mapped type, or nullptr if empty.

Returns: A pointer to the mapped type or nullptr if empty.

inline PointerType get() const noexcept

Returns a const pointer to the mapped type, or nullptr if empty.

Returns: A const pointer to the mapped type or nullptr if empty.

inline Handle handle() const noexcept

Returns the Handle referenced by *this.

Returns: The Handle referenced by *this.

inline explicit operator bool() const noexcept

Tests if *this contains a valid reference.

Returns: true if *this maintains a valid reference; false if *this is empty.

inline void reset(): Releases any associated reference and resets *this to empty.

inline void swap(ConstHandleRef &rhs): Swaps state with another HandleRef.

Protected Functions

inline ConstHandleRef(Database *db, Handle h, Mapped *m) noexcept

Protected constructor.

Not to be used externally.

Protected Attributes

Database *m_database = {}: Handle database this reference points into.

Handle m_handle = {}: Handle that this reference currently represents.

Mapped *m_mapped = {}: The mapped value for this reference.