std::optional::value

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

 

Utilities library

Type support (basic types, RTTI, type traits)

Dynamic memory management

Error handling

Program utilities

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Date and time

Function objects

initializer_list (C++11)

bitset

hash (C++11)

Relational operators

rel_ops::operator!= rel_ops::operator> rel_ops::operator<= rel_ops::operator>=

Pairs and tuples

pair

tuple (C++11)

piecewise_construct_t (C++11)

piecewise_construct (C++11)

Swap, forward and move

swap

forward (C++11)

move (C++11)

move_if_noexcept (C++11)

declval (C++11)

 

std::optional

Member functions

optional::optional

optional::~optional

optional::operator=

Observers

optional::operator-> optional::operator*

optional::operator bool

optional::value

optional::value_or

Modifiers

optional::emplace

optional::swap

Non-member functions

operator== operator<

make_optional

swap

Helper classes

hash

 

constexpr const T& value() const;		(since C++14)
T& value();		(since C++14)

Returns the contained value.

Parameters

(none)

Return value

A reference to the contained value.

Exceptions

std::bad_optional_access if *this is in disengaged state.

See also

value_or	returns the contained value if engaged, another value otherwise (public member function)