serac::variant< T0, T1 > Struct Template Reference

A simple variant type that supports only two elements. More...

#include <variant.hpp>

Public Member Functions
constexpr	variant ()=default
	Default constructor - will default-initialize first member of the variant.
constexpr	variant (const variant &)=default
	Default constructor. More...
constexpr	variant (variant &&)=default
	Default constructor.
template<typename T , typename SFINAE = std::enable_if_t<detail::is_variant_assignable<T, T0, T1>::value>>
constexpr	variant (T &&t)
	"Parameterized" constructor with which a value can be assigned More...
constexpr variant &	operator= (const variant &)=default
	Default assignment operator. More...
constexpr variant &	operator= (variant &&)=default
	Default assignment operator. More...
template<typename T , typename SFINAE = std::enable_if_t<detail::is_variant_assignable<T, T0, T1>::value>>
constexpr variant &	operator= (T &&t)
constexpr int	index () const
	Returns the index of the active variant member.

Public Attributes
detail::variant_storage< T0, T1 >	storage_
	Storage abstraction used to provide constexpr functionality when applicable.

Friends
template<int I>
constexpr friend variant_alternative< I, T0, T1 >::type &	get (variant &v)
	Returns the variant member at the provided index. More...
template<int I>
constexpr friend const variant_alternative< I, T0, T1 >::type &	get (const variant &v)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Detailed Description

template<typename T0, typename T1>
struct serac::variant< T0, T1 >

A simple variant type that supports only two elements.

Avoids the recursive template instantiation associated with std::variant and provides a (roughly) identical interface that is fully constexpr (when both types are trivially destructible)

Template Parameters

T0	The first member type of the variant
T1	The second member type of the variant

Definition at line 207 of file variant.hpp.

Constructor & Destructor Documentation

variant() [1/2]

template<typename T0 , typename T1 >

constexpr serac::variant< T0, T1 >::variant ( const variant< T0, T1 > &  )

constexprdefault

Default constructor.

Note

These are needed explicitly so the variant(T&&) doesn't match first

variant() [2/2]

template<typename T0 , typename T1 >

template<typename T , typename SFINAE = std::enable_if_t<detail::is_variant_assignable<T, T0, T1>::value>>

constexpr serac::variant< T0, T1 >::variant ( T &&  t )

inlineconstexpr

"Parameterized" constructor with which a value can be assigned

Template Parameters

T	The type of the parameter to assign to one of the variant elements

Parameters

[in]

t

The parameter to assign to the variant's contents

Precondition

The parameter type T must be equal to or assignable to either T0 or T1

Note

If the conversion is ambiguous, i.e., if t is equal or convertible to both T0 and T1, the first element of the variant - of type T0 - will be assigned to

Definition at line 238 of file variant.hpp.

Member Function Documentation

operator=() [1/3]

template<typename T0 , typename T1 >

constexpr variant& serac::variant< T0, T1 >::operator= ( const variant< T0, T1 > &  )

constexprdefault

Default assignment operator.

Note

These are needed explicitly so the operator=(T&&) doesn't match first

Returns

The modified variant

operator=() [2/3]

template<typename T0 , typename T1 >

template<typename T , typename SFINAE = std::enable_if_t<detail::is_variant_assignable<T, T0, T1>::value>>

constexpr variant& serac::variant< T0, T1 >::operator= ( T &&  t )

inlineconstexpr

"Parameterized" assignment with which a value can be assigned

Template Parameters

T	The type of the parameter to assign to one of the variant elements

Parameters

[in]

t

The parameter to assign to the variant's contents

See also

variant::variant(T&& t) for notes and preconditions

Definition at line 273 of file variant.hpp.

operator=() [3/3]

template<typename T0 , typename T1 >

constexpr variant& serac::variant< T0, T1 >::operator= ( variant< T0, T1 > &&  )

constexprdefault

Default assignment operator.

Returns

The modified variant

Friends And Related Function Documentation

get

template<typename T0 , typename T1 >

template<int I>

constexpr friend variant_alternative<I, T0, T1>::type& get ( variant< T0, T1 > &  v )

friend

Returns the variant member at the provided index.

Template Parameters

I	The index of the element to retrieve

See also

std::variant::get

Template Parameters

T	The type of the element to retrieve
T0	The first member type of the variant
T1	The second member type of the variant

Parameters

[in]

v

The variant to return the element of

See also

std::variant::get

Precondition

T must be either T0 or T1

Note

If T == T0 == T1, the element at index 0 will be returned

Definition at line 304 of file variant.hpp.

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

• src/serac/infrastructure/variant.hpp