std::expected<T,E>::emplace
| T is not cv void | ||
|
(1) | (since C++23) |
|
(2) | (since C++23) |
| T is cv void | ||
|
(3) | (since C++23) |
Constructs an expected value in-place. After the call, has_value() returns true.
1) Destroys the contained value, then initializes the expected value contained in
*this as if by direct-initializing an object of type T from the arguments std::forward<Args>(args).... This overload participates in overload resolution only if std::is_nothrow_constructible_v<T, Args...> is true.
2) Destroys the contained value, then initializes the expected value contained in
*this as if by direct-initializing an object of type T from the arguments il, std::forward<Args>(args).... This overload participates in overload resolution only if std::is_nothrow_constructible_v<T, std::initializer_list<U>&, Args...> is true.
3) If
*this contains an unexpected value, destroys that value.
Parameters
| args... | - | the arguments to pass to the constructor |
| il | - | the initializer list to pass to the constructor |
Return value
A reference to the new contained value.
Exceptions
noexcept specification:
noexcept
Notes
If the construction of T is potentially-throwing, this function is not defined. In this case, it is the responsibility of the user to create a temporary and move or copy it.
Example
See also
| assigns contents (public member function) |
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