22 General utilities library [utilities]

22.7 Storage for any type [any]

22.7.4 Class any [any.class]

22.7.4.4 Modifiers [any.modifiers]

🔗
template<class T, class... Args> decay_t<T>& emplace(Args&&... args);
1
#
Let VT be decay_t<T>.
2
#
Constraints: is_copy_constructible_v<VT> is true and is_constructible_v<VT, Args...> is true.
3
#
Preconditions: VT meets the Cpp17CopyConstructible requirements.
4
#
Effects: Calls reset().
Then direct-non-list-initializes the contained value of type VT with std​::​forward<Args>(args)....
5
#
Postconditions: *this contains a value.
6
#
Returns: A reference to the new contained value.
7
#
Throws: Any exception thrown by the selected constructor of VT.
8
#
Remarks: If an exception is thrown during the call to VT's constructor, *this does not contain a value, and any previously contained value has been destroyed.
🔗
template<class T, class U, class... Args> decay_t<T>& emplace(initializer_list<U> il, Args&&... args);
9
#
Let VT be decay_t<T>.
10
#
Constraints: is_copy_constructible_v<VT> is true and is_constructible_v<VT, initializer_list<U>&, Args...> is true.
11
#
Preconditions: VT meets the Cpp17CopyConstructible requirements.
12
#
Effects: Calls reset().
Then direct-non-list-initializes the contained value of type VT with il, std​::​forward<Args>(args)....
13
#
Postconditions: *this contains a value.
14
#
Returns: A reference to the new contained value.
15
#
Throws: Any exception thrown by the selected constructor of VT.
16
#
Remarks: If an exception is thrown during the call to VT's constructor, *this does not contain a value, and any previously contained value has been destroyed.
🔗
void reset() noexcept;
17
#
Effects: If has_value() is true, destroys the contained value.
18
#
Postconditions: has_value() is false.
🔗
void swap(any& rhs) noexcept;
19
#
Effects: Exchanges the states of *this and rhs.