expected

20.35.13

STL equivalent: std::expected

A generic result type for returning either a result or an error.

Replacement for etl::result

template <typename TValue, typename TError>

class expected

Specialisation for void result.

template <typename TError>

class expected<void, TError>

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Unexpected type

template <typename TError>

class unexpected<TError>

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A tag type for in-place construction of an unexpected value in an etl::expected object

struct unexpect_t;

A constant of type etl::unexpect_t which is directly passed to a constructor of etl::expected to construct an

unexpected value.

inline constexpr unexpect_t unexpect; >= C++17

static const unexpect_t unexpect; < C++17

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unexpected

template <typename TError>

class unexpected<TError>

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Types

error_type TError

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Member functions

ETL_CONSTEXPR

unexpected(const unexpected& other)

Copy constructor

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ETL_CONSTEXPR

unexpected(unexpected&& other)

Move constructor.

>= C++11

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template <typename TError>

constexpr explicit unexpected(TError&& e)

Construct from argument.

>= C++11

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template <typename TError>

explicit unexpected(const TError& e)

Construct from argument.

< C++11

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template <typename... TArgs>

constexpr explicit unexpected(etl::in_place_t, TArgs&&... args)

Construct from arguments.

>= C++11

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template <typename U, typename... TArgs>

constexpr explicit unexpected(etl::in_place_t, std::initializer_list<U> init, TArgs&&... args)

Construct from initializer_list and arguments.

>= C++11

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ETL_CONSTEXPR14

etl::unexpected<TError>& operator =(const etl::unexpected<TError>& rhs)

Assign from etl::unexpected

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ETL_CONSTEXPR14

etl::unexpected<TError>& operator =(etl::unexpected<TError>&& rhs)

Move assign from etl::unexpected

>= C++11

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TError& error() & noexcept

Get the error.

>= C++11

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constexpr const TError& error() const& noexcept

Get the error.

>= C++11

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TError&& error() && noexcept

Get the error.

>= C++11

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constexpr TError&& error() const&& noexcept

Get the error.

>= C++11

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const TError& error() const

Get the error.

< C++11

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void swap(etl::unexpected<TError>& other)

Swap with another etl::unexpected

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expected

template <typename TValue, typename TError>

class expected

Specialisation for void value type.

template <typename TError>

class expected<void, TError>

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Types

this_type etl::expected<TValue, TError>

value_type TValue

error_type TError

unexpected_type etl::unexpected<TError>

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Member functions

ETL_CONSTEXPR14 expected() ETL_NOEXCEPT

Default constructor

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ETL_CONSTEXPR14 expected(const value_type& value) ETL_NOEXCEPT

Constructor

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ETL_CONSTEXPR14 expected(value_type&& value) ETL_NOEXCEPT

Constructor

>= C++11

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ETL_CONSTEXPR14 expected(const expected& other) ETL_NOEXCEPT

Copy constructor

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ETL_CONSTEXPR14 expected(expected&& other) ETL_NOEXCEPT

Move constructor

>= C++11

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template <typename F>

ETL_CONSTEXPR14 explicit expected(const etl::unexpected<F>& ue)

Copy construct from unexpected type.

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template <typename F>

ETL_CONSTEXPR14 explicit expected(etl::unexpected<F>&& ue)

Move construct from unexpected type.

>= C++11

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ETL_CONSTEXPR14 explicit expected(etl::in_place_t) ETL_NOEXCEPT

Construct with default value type.

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template <typename... TArgs>

ETL_CONSTEXPR14 explicit expected(etl::in_place_t, TArgs&&... args)

Construct value type from arguments.

>= C++11

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template <typename U, typename... TArgs>

ETL_CONSTEXPR14 explicit expected(etl::in_place_t, std::initializer_list<U> il, TArgs&&... args)

Construct value type from initializer_list and arguments.

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template <typename... TArgs>

ETL_CONSTEXPR14 explicit expected(etl::unexpect_t, TArgs&&... args)

Construct error type from arguments.

>= C++11

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template <typename U, typename... TArgs>

ETL_CONSTEXPR14 explicit expected(etl::unexpect_t, std::initializer_list<U> il, TArgs&&... args)

Construct error type from initializer_list and arguments.

>= C++11

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this_type& operator =(const this_type& other)

Copy assign

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this_type& operator =(this_type&& other)

Move assign

>= C++11

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expected& operator =(const value_type& value)

Copy assign from value

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expected& operator =(value_type&& value)

Move assign from value

>= C++11

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expected& operator =(const unexpected_type& error)

Copy assign from error

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expected& operator =(unexpected_type&& error)

Move assign from error

>= C++11

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ETL_CONSTEXPR14 value_type& value()&

Get the value.

Undefined if has_value() returns false.

Not valid for void specialisation.

>= C++11

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ETL_CONSTEXPR14 const value_type& value() const&

Get the value.

Undefined if has_value() returns false.

Not valid for void specialisation.

>= C++11

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ETL_CONSTEXPR14 value_type&& value()&&

Get the value.

Undefined if has_value() returns false.

Not valid for void specialisation.

>= C++11

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ETL_CONSTEXPR14 const value_type&& value() const&&

Get the value.

Undefined if has_value() returns false.

Not valid for void specialisation.

>= C++11

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value_type& value() const

Get the value.

Undefined if has_value() returns false.

Not valid for void specialisation.

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ETL_NODISCARD

ETL_CONSTEXPR14

bool has_value() const

Returns true if the class contains a value.

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ETL_NODISCARD

ETL_CONSTEXPR14

operator bool() const

Returns true if the class contains a value.

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template <typename U>

ETL_NODISCARD

ETL_CONSTEXPR14

value_type value_or(U&& default_value) const&

Returns the value or default_value if has_value() returns false.

>= C++11

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template <typename U>

ETL_NODISCARD

ETL_CONSTEXPR14

value_type value_or(U&& default_value)&&

Returns the value or default_value if has_value() returns false.

>= C++11

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template <typename U>

value_type value_or(const U& default_value) const

Returns the value or default_value if has_value() returns false.

< C++11

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ETL_NODISCARD

ETL_CONSTEXPR14

error_type& error()& ETL_NOEXCEPT

Returns the error.

Undefined if has_value() returns true.

>= C++11

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ETL_NODISCARD

ETL_CONSTEXPR14

const error_type& error() const& ETL_NOEXCEPT

Returns the error.

Undefined if has_value() returns true.

>= C++11

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ETL_NODISCARD

ETL_CONSTEXPR14

error_type&& error() && ETL_NOEXCEPT

Returns the error.

Undefined if has_value() returns true.

>= C++11

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ETL_NODISCARD

ETL_CONSTEXPR14

const error_type&& error() const&& ETL_NOEXCEPT

Returns the error.

Undefined if has_value() returns true.

>= C++11

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error_type& error() const

Returns the error.

Undefined if has_value() returns true.

< C++11

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template <typename... TArgs>

ETL_CONSTEXPR14 value_type& emplace(TArgs&&... args) ETL_NOEXCEPT

Returns the error if has_value() returns false.

Undefined if has_value() returns true.

>= C++11

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template <typename U, typename... TArgs>

ETL_CONSTEXPR14 value_type& emplace(std::initializer_list<U>& il, TArgs&&... args) ETL_NOEXCEPT

Create from arguments.

>= C++11

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value_type* operator ->()

Class member access operator.

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const value_type* operator ->() const

Const class member access operator.

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value_type& operator *()

Dereference operator.

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const value_type& operator *() const

Dereference operator.

expected.h