std::optional::value - cppreference.com (original) (raw)
| constexpr T& value() &; constexpr const T& value() const &; | (1) | (since C++17) |
|---|---|---|
| constexpr T&& value() &&; constexpr const T&& value() const &&; | (2) | (since C++17) |
If *this contains a value, returns a reference to the contained value.
Otherwise, throws a std::bad_optional_access exception.
[edit] Parameters
(none)
[edit] Return value
A reference to the contained value.
[edit] Exceptions
std::bad_optional_access if *this does not contain a value.
[edit] Notes
The dereference operator operator*() does not check if this optional contains a value, which may be more efficient than value().
[edit] Example
Output:
bad optional access bad optional access 43 44