mx::Wrapper< T > Class Template Reference

A nullable smart wrapper around a raw pointer. More...

#include <wrapper.hpp>

Public Member Functions
	Wrapper ()
	Default constructor — initialises to nullopt (no value).
	Wrapper (const T &t)
	Construct from a raw pointer.
	Wrapper (std::nullopt_t n)
	Construct in the empty (nullopt) state.
	Wrapper (const Wrapper< T > &w)
	Copy constructor.
	Wrapper (Wrapper< T > &&w)
	Move constructor.
	~Wrapper ()=default
Wrapper< T > &	operator= (const T &t)
	Assign from a raw pointer.
Wrapper< T > &	operator= (std::nullopt_t n)
	Reset to the empty (nullopt) state.
Wrapper< T > &	operator= (const Wrapper< T > &w)
	Copy-assign from another Wrapper.
Wrapper< T > &	operator= (Wrapper< T > &&w)
	Move-assign from another Wrapper.
bool	has_value () const
	Check whether a non-null value is held.
T	value ()
	Access the stored pointer without null checking.
T	expect (const std::string &msg)
	Unwrap with a custom panic message on null.
T	unwrap ()
	Unwrap the stored pointer, panicking on null.
T	unwrap_or (T value)
	Return the stored pointer or a fallback if null.

Private Attributes
std::optional< T >	type
	Internal optional storage.

Detailed Description

template<WrapType T>
class mx::Wrapper< T >

A nullable smart wrapper around a raw pointer.

Stores an optional pointer. Accessors throw mx::Exception if the pointer is null (unwrap, expect) or return a fallback (unwrap_or).

Template Parameters

T	A raw pointer type (must satisfy WrapType concept).

Definition at line 36 of file wrapper.hpp.

Constructor & Destructor Documentation

Wrapper() [1/5]

template<WrapType T>

mx::Wrapper< T >::Wrapper ( )

inline

Default constructor — initialises to nullopt (no value).

Definition at line 39 of file wrapper.hpp.

References type.

Referenced by operator=(), operator=(), operator=(), operator=(), Wrapper(), and Wrapper().

Wrapper() [2/5]

template<WrapType T>

mx::Wrapper< T >::Wrapper ( const T & t )

inline

Construct from a raw pointer.

Parameters

t	Pointer to wrap.

Definition at line 45 of file wrapper.hpp.

References type.

Wrapper() [3/5]

template<WrapType T>

mx::Wrapper< T >::Wrapper ( std::nullopt_t n )

inline

Construct in the empty (nullopt) state.

Parameters

n	std::nullopt.

Definition at line 51 of file wrapper.hpp.

References type.

Wrapper() [4/5]

template<WrapType T>

mx::Wrapper< T >::Wrapper ( const Wrapper< T > & w )

inline

Copy constructor.

Definition at line 54 of file wrapper.hpp.

References type, and Wrapper().

Wrapper() [5/5]

template<WrapType T>

mx::Wrapper< T >::Wrapper ( Wrapper< T > && w )

inline

Move constructor.

Definition at line 57 of file wrapper.hpp.

References type, and Wrapper().

~Wrapper()

template<WrapType T>

mx::Wrapper< T >::~Wrapper ( )

default

Member Function Documentation

expect()

template<WrapType T>

T mx::Wrapper< T >::expect ( const std::string & msg )

inline

Unwrap with a custom panic message on null.

Parameters

msg	Message to include in the thrown mx::Exception.

Returns

The stored pointer.

Exceptions

mx::Exception

if the value is null or absent.

Definition at line 118 of file wrapper.hpp.

References type.

has_value()

template<WrapType T>

bool mx::Wrapper< T >::has_value ( ) const

inline

Check whether a non-null value is held.

Returns

true if a non-null pointer is stored.

Definition at line 97 of file wrapper.hpp.

References type.

operator=() [1/4]

template<WrapType T>

Wrapper< T > & mx::Wrapper< T >::operator= ( const T & t )

inline

Assign from a raw pointer.

Parameters

t	Pointer to store.

Returns

Reference to this.

Definition at line 66 of file wrapper.hpp.

References type, and Wrapper().

operator=() [2/4]

template<WrapType T>

Wrapper< T > & mx::Wrapper< T >::operator= ( const Wrapper< T > & w )

inline

Copy-assign from another Wrapper.

Definition at line 82 of file wrapper.hpp.

References type, and Wrapper().

operator=() [3/4]

template<WrapType T>

Wrapper< T > & mx::Wrapper< T >::operator= ( std::nullopt_t n )

inline

Reset to the empty (nullopt) state.

Parameters

n	std::nullopt.

Returns

Reference to this.

Definition at line 76 of file wrapper.hpp.

References type, and Wrapper().

operator=() [4/4]

template<WrapType T>

Wrapper< T > & mx::Wrapper< T >::operator= ( Wrapper< T > && w )

inline

Move-assign from another Wrapper.

Definition at line 88 of file wrapper.hpp.

References type, and Wrapper().

unwrap()

template<WrapType T>

T mx::Wrapper< T >::unwrap ( )

inline

Unwrap the stored pointer, panicking on null.

Returns

The stored pointer.

Exceptions

mx::Exception

if the value is null or absent.

Definition at line 132 of file wrapper.hpp.

References type.

unwrap_or()

template<WrapType T>

T mx::Wrapper< T >::unwrap_or ( T value )

inline

Return the stored pointer or a fallback if null.

Parameters

value

Fallback pointer returned when no value is held.

Returns

The stored pointer, or value if null/absent.

Definition at line 147 of file wrapper.hpp.

References type, and value().

value()

template<WrapType T>

T mx::Wrapper< T >::value ( )

inline

Access the stored pointer without null checking.

Returns

The stored pointer (may be nullptr if constructed from nullopt).

Definition at line 108 of file wrapper.hpp.

References type.

Referenced by unwrap_or().

Member Data Documentation

type

template<WrapType T>

std::optional<T> mx::Wrapper< T >::type

private

Internal optional storage.

Definition at line 154 of file wrapper.hpp.

Referenced by expect(), has_value(), operator=(), operator=(), operator=(), operator=(), unwrap(), unwrap_or(), value(), Wrapper(), Wrapper(), Wrapper(), Wrapper(), and Wrapper().

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

• wrapper.hpp