NAME¶

std::expected::value_or - std::expected::value_or

Synopsis¶

template< class U > (1) (since C++23)
constexpr T value_or( U&& default_value ) const&;
template< class U > (2) (since C++23)
constexpr T value_or( U&& default_value ) &&;

Returns the contained value if *this contains an expected value, otherwise returns
default_value.

1) Returns bool(*this) ? **this : static_cast<T>(std::forward<U>(default_value))
2) Returns bool(*this) ? std::move(**this) :
static_cast<T>(std::forward<U>(default_value))

Parameters¶

default_value - the value to use in case *this does not contain an expected value

Type requirements¶

-
T must meet the requirements of CopyConstructible in order to use overload (1).
-
T must meet the requirements of MoveConstructible in order to use overload (2).
-
U&& must be convertible to T

Return value¶

The currently contained value if *this contains an expected value, or default_value
otherwise.

Exceptions¶

Any exception thrown by the selected constructor of the return value T.

Notes¶

If T is (possibly cv-qualified) void, this member is not declared.

Example¶

This section is incomplete
Reason: no example

See also¶

value returns the expected value
(public member function)

Category:¶

* Todo no example