original::alternative< void > Class Reference

Collaboration diagram for original::alternative< void >:

Public Member Functions
	alternative ()
	Constructs an empty alternative<void>
	alternative (null n)
	Constructs from null (empty state)
	alternative (std::in_place_t t)
	Constructs with value present.
void	set () noexcept
	Sets the alternative to have a value.
alternative &	operator= (std::in_place_t t) noexcept
	Assignment from in_place tag to set as present.
alternative &	operator= (null n) noexcept
	Assignment from null to reset to empty state.
void	reset () noexcept
	Resets to empty state.
bool	hasValue () const
	Checks if contains a value.
	operator bool () const
	Boolean conversion operator.
	alternative (const alternative &other)=default
	Default copy constructor.
alternative &	operator= (const alternative &other)=default
	Default copy assignment.
	alternative (alternative &&other) noexcept
	Move constructor.
alternative &	operator= (alternative &&other) noexcept
	Move assignment.
void	swap (alternative &other) noexcept
	Swaps contents with another alternative<void>
	~alternative ()=default
	Default destructor.

Constructor & Destructor Documentation

alternative() [1/3]

original::alternative< void >::alternative ( )

inlineexplicitdefault

Constructs an empty alternative<void>

Postcondition

hasValue() == false

alternative() [2/3]

original::alternative< void >::alternative ( null  n )

inlineexplicit

Constructs from null (empty state)

Parameters

n	null value indicating empty state

Postcondition

hasValue() == false

alternative() [3/3]

original::alternative< void >::alternative ( std::in_place_t  t )

inlineexplicit

Constructs with value present.

Parameters

t	std::in_place_t tag to indicate value should be present

Postcondition

hasValue() == true

Member Function Documentation

hasValue()

bool original::alternative< void >::hasValue ( ) const

inline

Checks if contains a value.

Returns

true if contains value, false if empty

operator bool()

original::alternative< void >::operator bool ( ) const

inlineexplicit

Boolean conversion operator.

Returns

true if contains value, false if empty

operator=() [1/2]

original::alternative< void > & original::alternative< void >::operator= ( null  n )

inlinenoexcept

Assignment from null to reset to empty state.

Parameters

n	null value indicating empty state

Returns

Reference to this alternative

Postcondition

hasValue() == false

Resets the alternative<void> to the empty state. This operation is equivalent to calling reset() but provides a more expressive syntax when working with null values. The assignment clears the "present" state and ensures the alternative is empty.

Example usage:

alternative<void> flag(std::in_place);  // Present state
flag = original::null;                  // Now empty
 
if (!flag) {
    // This will execute since flag is now empty
}
 
// In generic code:
template<typename T>
void clearAlternative(alternative<T>& opt) {
    opt = original::null;  // Works for both alternative<T> and alternative<void>
}

Note

This operation is noexcept and always succeeds.

See also

reset()

operator=() [2/2]

original::alternative< void > & original::alternative< void >::operator= ( std::in_place_t  t )

inlinenoexcept

Assignment from in_place tag to set as present.

Parameters

t	std::in_place_t tag to indicate value should be present

Returns

Reference to this alternative

Postcondition

hasValue() == true

Sets the alternative<void> to the "present" state without storing any actual data. This is equivalent to calling set() but allows for more expressive syntax in template code.

Example usage:

alternative<void> flag;
flag = std::in_place;  // Now has value present
 
// In template context:
template<typename T>
void setPresent(alternative<T>& opt) {
    opt = std::in_place;
}

Note

This operation is noexcept and always succeeds.

See also

set()

reset()

void original::alternative< void >::reset ( )

inlinenoexcept

Resets to empty state.

Postcondition

hasValue() == false

set()

void original::alternative< void >::set ( )

inlinenoexcept

Sets the alternative to have a value.

Postcondition

hasValue() == true

swap()

void original::alternative< void >::swap ( alternative< void > &  other )

inlinenoexcept

Swaps contents with another alternative<void>

Parameters

other

Alternative to swap with

Note

No-throw guarantee

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

• src/core/optional.h