etl::optional class template More...

Classes
struct	bad_optional_access
	Defines a type of object to be thrown by etl::optional::value when accessing an optional object that does not contain a value. More...

struct	hash< etl::optional< T > >
	The template specialization of etl::hash for the etl::optional class allows users to obtain hashes of the values contained in optional objects. More...

struct	nullopt_t
	etl::nullopt_t is an empty class type used to indicate optional type with uninitialized state. In particular, etl::optional has a constructor with nullopt_t as a single argument, which creates an optional that does not contain a value. More...

struct	optional< T >
	The class template optional manages an optional contained value, i.e. a value that may or may not be present. More...

Functions
template<typename T>
	optional (T) -> optional< T >

template<typename T, typename... Args>
constexpr auto	make_optional (Args &&... args) -> etl::optional< T >
	Creates an optional object constructed in-place from args...

template<typename T>
constexpr auto	make_optional (T &&value) -> etl::optional< etl::decay_t< T > >
	Creates an optional object from value.

template<typename T>
constexpr auto	operator< (etl::nullopt_t, optional< T > const &opt) noexcept -> bool
	Compares opt with a nullopt.

template<typename T>
constexpr auto	operator< (optional< T > const &, etl::nullopt_t) noexcept -> bool
	Compares opt with a nullopt.

template<typename T, typename U>
constexpr auto	operator< (optional< T > const &lhs, optional< U > const &rhs) -> bool
	Compares two optional objects, lhs and rhs.

template<typename T, typename U>
constexpr auto	operator< (optional< T > const &opt, U const &value) -> bool
	Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

template<typename T, typename U>
constexpr auto	operator< (T const &value, optional< U > const &opt) -> bool
	Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

template<typename T, typename U>
constexpr auto	operator<= (optional< T > const &lhs, optional< U > const &rhs) -> bool
	Compares two optional objects, lhs and rhs.

template<typename T, typename U>
constexpr auto	operator<= (optional< T > const &opt, U const &value) -> bool
	Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

template<typename T, typename U>
constexpr auto	operator<= (T const &value, optional< U > const &opt) -> bool
	Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

template<typename T>
constexpr auto	operator== (etl::nullopt_t, optional< T > const &opt) noexcept -> bool
	Compares opt with a nullopt.

template<typename T, typename U>
constexpr auto	operator== (optional< T > const &lhs, optional< U > const &rhs) -> bool
	Compares two optional objects, lhs and rhs.

template<typename T>
constexpr auto	operator== (optional< T > const &opt, etl::nullopt_t) noexcept -> bool
	Compares opt with a nullopt.

template<typename T, typename U>
constexpr auto	operator== (optional< T > const &opt, U const &value) -> bool
	Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

template<typename T, typename U>
constexpr auto	operator> (optional< T > const &lhs, optional< U > const &rhs) -> bool
	Compares two optional objects, lhs and rhs.

template<typename T, typename U>
constexpr auto	operator> (optional< T > const &opt, U const &value) -> bool
	Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

template<typename T, typename U>
constexpr auto	operator> (T const &value, optional< U > const &opt) -> bool
	Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

template<typename T, typename U>
constexpr auto	operator>= (optional< T > const &lhs, optional< U > const &rhs) -> bool
	Compares two optional objects, lhs and rhs.

template<typename T, typename U>
constexpr auto	operator>= (optional< T > const &opt, U const &value) -> bool
	Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

template<typename T, typename U>
constexpr auto	operator>= (T const &value, optional< U > const &opt) -> bool
	Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

Variables
constexpr auto	nullopt = etl::nullopt_t{0}
	etl::nullopt is a constant of type etl::nullopt_t that is used to indicate optional type with uninitialized state.

Detailed Description

etl::optional class template

Function Documentation

◆ optional()

template<typename T>

optional ( T ) -> optional< T >

◆ make_optional() [1/2]

template<typename T, typename... Args>

auto make_optional ( Args &&... args ) -> etl::optional<T>

Creates an optional object constructed in-place from args...

◆ make_optional() [2/2]

template<typename T>

auto make_optional ( T && value ) -> etl::optional<etl::decay_t<T>>

Creates an optional object from value.

◆ operator<() [1/5]

template<typename T>

auto operator<	(	etl::nullopt_t	,
		optional< T > const &	opt ) -> bool

Compares opt with a nullopt.

Equivalent to when comparing to an optional that does not contain a value.

◆ operator<() [2/5]

template<typename T>

auto operator<	(	optional< T > const &	,
		etl::nullopt_t	) -> bool

Compares opt with a nullopt.

Equivalent to when comparing to an optional that does not contain a value.

◆ operator<() [3/5]

template<typename T, typename U>

auto operator<	(	optional< T > const &	lhs,
		optional< U > const &	rhs ) -> bool

Compares two optional objects, lhs and rhs.

◆ operator<() [4/5]

template<typename T, typename U>

auto operator<	(	optional< T > const &	opt,
		U const &	value ) -> bool

Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

https://en.cppreference.com/w/cpp/utility/optional/operator_cmp

◆ operator<() [5/5]

template<typename T, typename U>

auto operator<	(	T const &	value,
		optional< U > const &	opt ) -> bool

Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

https://en.cppreference.com/w/cpp/utility/optional/operator_cmp

◆ operator<=() [1/3]

template<typename T, typename U>

auto operator<=	(	optional< T > const &	lhs,
		optional< U > const &	rhs ) -> bool

Compares two optional objects, lhs and rhs.

◆ operator<=() [2/3]

template<typename T, typename U>

auto operator<=	(	optional< T > const &	opt,
		U const &	value ) -> bool

Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

https://en.cppreference.com/w/cpp/utility/optional/operator_cmp

◆ operator<=() [3/3]

template<typename T, typename U>

auto operator<=	(	T const &	value,
		optional< U > const &	opt ) -> bool

Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

https://en.cppreference.com/w/cpp/utility/optional/operator_cmp

◆ operator==() [1/4]

template<typename T>

auto operator==	(	etl::nullopt_t	,
		optional< T > const &	opt ) -> bool

Compares opt with a nullopt.

Equivalent to when comparing to an optional that does not contain a value.

◆ operator==() [2/4]

template<typename T, typename U>

auto operator==	(	optional< T > const &	lhs,
		optional< U > const &	rhs ) -> bool

Compares two optional objects, lhs and rhs.

◆ operator==() [3/4]

template<typename T>

auto operator==	(	optional< T > const &	opt,
		etl::nullopt_t	) -> bool

Compares opt with a nullopt.

Equivalent to when comparing to an optional that does not contain a value.

◆ operator==() [4/4]

template<typename T, typename U>

auto operator==	(	optional< T > const &	opt,
		U const &	value ) -> bool

Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

https://en.cppreference.com/w/cpp/utility/optional/operator_cmp

◆ operator>() [1/3]

template<typename T, typename U>

auto operator>	(	optional< T > const &	lhs,
		optional< U > const &	rhs ) -> bool

Compares two optional objects, lhs and rhs.

◆ operator>() [2/3]

template<typename T, typename U>

auto operator>	(	optional< T > const &	opt,
		U const &	value ) -> bool

Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

https://en.cppreference.com/w/cpp/utility/optional/operator_cmp

◆ operator>() [3/3]

template<typename T, typename U>

auto operator>	(	T const &	value,
		optional< U > const &	opt ) -> bool

Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

https://en.cppreference.com/w/cpp/utility/optional/operator_cmp

◆ operator>=() [1/3]

template<typename T, typename U>

auto operator>=	(	optional< T > const &	lhs,
		optional< U > const &	rhs ) -> bool

Compares two optional objects, lhs and rhs.

◆ operator>=() [2/3]

template<typename T, typename U>

auto operator>=	(	optional< T > const &	opt,
		U const &	value ) -> bool

Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

https://en.cppreference.com/w/cpp/utility/optional/operator_cmp

◆ operator>=() [3/3]

template<typename T, typename U>

auto operator>=	(	T const &	value,
		optional< U > const &	opt ) -> bool

Compares opt with a value. The values are compared (using the corresponding operator of T) only if opt contains a value. Otherwise, opt is considered less than value. If the corresponding two-way comparison expression between *opt and value is not well-formed, or if its result is not convertible to bool, the program is ill-formed.

https://en.cppreference.com/w/cpp/utility/optional/operator_cmp

Variable Documentation

◆ nullopt

auto nullopt = etl::nullopt_t{0}

etl::nullopt is a constant of type etl::nullopt_t that is used to indicate optional type with uninitialized state.

Classes

Functions

Variables

Detailed Description

Function Documentation

◆ optional()

◆ make_optional() [1/2]

◆ make_optional() [2/2]

◆ operator<() [1/5]

◆ operator<() [2/5]

◆ operator<() [3/5]

◆ operator<() [4/5]

◆ operator<() [5/5]

◆ operator<=() [1/3]

◆ operator<=() [2/3]

◆ operator<=() [3/3]

◆ operator==() [1/4]

◆ operator==() [2/4]

◆ operator==() [3/4]

◆ operator==() [4/4]

◆ operator>() [1/3]

◆ operator>() [2/3]

◆ operator>() [3/3]

◆ operator>=() [1/3]

◆ operator>=() [2/3]

◆ operator>=() [3/3]

Variable Documentation

◆ nullopt