std::flat_set<Key,Compare,KeyContainer>::emplace - cppreference.com (original) (raw)

| 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

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.

Contents

[edit] Parameters

args - arguments to forward to the constructor of the element

[edit] 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.

[edit] Exceptions

If an exception is thrown for any reason, this function has no effect (strong exception safety guarantee).

[edit] Complexity

Logarithmic in the size of the container.

[edit] Notes

Careful use of emplace allows the new element to be constructed while avoiding unnecessary copy or move operations.

[edit] Example

[edit] See also