std::flat_set<Key,Compare,KeyContainer>:: emplace
|
template
<
class
...
Args
>
std:: pair < iterator, bool > emplace ( Args && ... args ) ; |
(since C++23)
(constexpr since C++26) |
|
Inserts a new element into the container constructed in-place with the given args , if there is no element with the key in the container.
First, initializes an object t of type
value_type
with
std::
forward
<
Args
>
(
args
)
...
, then inserts
t
as if by
auto it = ranges::upper_bound(c, t, compare); c.insert(it, std::move(t));
This overload participates in overload resolution only if std:: is_constructible_v < value_type, Args... > is true .
If
value_type
is not
EmplaceConstructible
into
flat_set
from
args
, the behavior is undefined.
| Information on iterator invalidation is copied from here |
Contents |
Parameters
| args | - | arguments to forward to the constructor of the element |
Return value
A pair consisting of an iterator to the inserted element (or to the element that prevented the insertion) and a bool value set to true if and only if the insertion took place.
Exceptions
If an exception is thrown for any reason, this function has no effect ( strong exception safety guarantee ).
Complexity
Logarithmic in the size of the container.
Notes
Careful use of
emplace
allows the new element to be constructed while avoiding unnecessary copy or move operations.
Example
|
This section is incomplete
Reason: no example |
See also
|
constructs elements in-place using a hint
(public member function) |
|
|
inserts elements
(public member function) |