# std::vector<T,Allocator>::emplace

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< cpp‎ | container‎ | vector

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 other than by the copy constructor, move constructor, assignment operator, or move assignment operator of the value type, or if an exception is thrown while `emplace` is used to insert a single element at the end and the value type is either CopyInsertable or nothrow move constructible, there are no effects (strong exception guarantee).

Otherwise, the effects are unspecified.

### Notes

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

### See also

insert | inserts elements (public member function)

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