std::expected<T,E>::~expected

 

C++

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Utilities library

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std::expected

Member functions

expected::expected

expected::~expected

expected::operator=

Observers

expected::operator->expected::operator*

expected::operator boolexpected::has_value

expected::value

expected::error

expected::value_or

expected::error_or

Monadic operations

expected::and_then

expected::or_else

expected::transform

expected::transform_error

Modifiers

expected::emplace

expected::swap

Non-member functions

operator==(std::expected)

swap(std::expected)

Helper classes

unexpected

bad_expected_access

unexpect_tunexpect

 

constexpr ~expected();		(since C++23)

Main template destructor

Destroys the contained value:

• If has_value() is true, destroys the expected value.
• Otherwise, destroys the unexpected value.

This destructor is trivial if std::is_trivially_destructible_v<T> and std::is_trivially_destructible_v<E> are both true.

void partial specialization destructor

If has_value() is false, destroys the unexpected value.

This destructor is trivial if std::is_trivially_destructible_v<E> is true.

Example

Run this code

#include <expected>
#include <print>
 
void info(auto name, int x)
{
    std::println("{} : {}", name, x);
}
 
struct Value
{
    int o{};
    ~Value() { info(__func__, o); }
};
 
struct Error
{
    int e{};
    ~Error() { info(__func__, e); }
};
 
int main()
{
    std::expected<Value, Error> e1{42};
    std::expected<Value, Error> e2{std::unexpect, 13};
    std::expected<void, Error> e3{std::unexpect, 37};
}

Output:

~Error : 37
~Error : 13
~Value : 42