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# std::deque::emplace

From cppreference.com
< cpp‎ | container‎ | deque

[edit template]

template< class... Args > iterator emplace( const_iterator pos, Args&&... args ); |  | (since C++11)

Inserts a new element into the container directly before `pos`. The element is constructed through std::allocator_traits::construct, which typically uses placement-new to construct the element in-place at a location provided by the container. The arguments `args...` are forwarded to the constructor as std::forward<Args>(args)....

All iterators, including the past-the-end iterator, are invalidated. References are invalidated too, unless pos == begin() or pos == end(), in which case they are not invalidated.

### [edit] Parameters

pos | - | iterator before which the new element will be constructed
args | - | arguments to forward to the constructor of the element
Type requirements
- `T (the container's element type)` must meet the requirements of `MoveAssignable`, `MoveInsertable` and `EmplaceConstructible`.

### [edit] Return value

Iterator pointing to the emplaced element.

### [edit] Complexity

Linear in the lesser of the distances between `pos` and either of the ends of the container.

### [edit] Exceptions

If an exception is thrown (e.g. by the constructor), the container is left unmodified, as if this function was never called (strong exception guarantee).

### [edit] See also

insert | inserts elements (public member function) [edit]

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