std::vector::emplace

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)....

If the new size() is greater than capacity(), all iterators and references are invalidated. Otherwise, only the iterators and references before the insertion point remain valid. The past-the-end iterator is also invalidated.

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`.

Return value

Iterator pointing to the emplaced element.

Complexity

Linear in the distance between pos and end of the container.

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).

Notes

The specialization std::vector<bool> did not have emplace() member until C++14.