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# std::map::insert

From cppreference.com
< cpp‎ | container‎ | map

std::pair<iterator,bool> insert( const value_type& value ); | (1) |
template< class P > std::pair<iterator,bool> insert( P&& value ); | (2) | (since C++11)
| (3) |
iterator insert( iterator hint, const value_type& value ); |  | (until C++11)
iterator insert( const_iterator hint, const value_type& value ); |  | (since C++11)
template< class P > iterator insert( const_iterator hint, P&& value ); | (4) | (since C++11)
template< class InputIt > void insert( InputIt first, InputIt last ); | (5) |
void insert( std::initializer_list<value_type> ilist ); | (6) | (since C++11)

Inserts element(s) into the container, if the container doesn't already contain an element with an equivalent key.

1-2) Inserts `value`. The overload (2) is equivalent to emplace(std::forward<P>(value)) and only participates in overload resolution if std::is_constructible<value_type, P&&>::value == true.
3-4) Inserts `value` in the position as close as possible, just prior(since C++11), to `hint`. The overload (4) is equivalent to emplace_hint(hint, std::forward<P>(value)) and only participates in overload resolution if std::is_constructible<value_type, P&&>::value == true.
5) Inserts elements from range `[first, last)`.
6) Inserts elements from initializer list `ilist`.

No iterators or references are invalidated.

### [edit] Parameters

hint | - | iterator, used as a suggestion as to where to insert the content
value | - | element value to insert
first, last | - | range of elements to insert
ilist | - | initializer list to insert the values from
Type requirements
- `InputIt` must meet the requirements of `InputIterator`.

### [edit] Return value

1-2) Returns a pair consisting of an iterator to the inserted element (or to the element that prevented the insertion) and a bool denoting whether the insertion took place.
3-4) Returns an iterator to the inserted element, or to the element that prevented the insertion.
5-6) (none)

### [edit] Exceptions

1-4) If an exception is thrown by any operation, the insertion has no effect.

| This section is incomplete Reason: cases 5-6

### [edit] Complexity

1-2) Logarithmic in the size of the container, `O(log(size()))`.

3-4) Amortized constant if the insertion happens in the position just after the hint, logarithmic in the size of the container otherwise. | (until C++11)
3-4) Amortized constant if the insertion happens in the position just before the hint, logarithmic in the size of the container otherwise. | (since C++11)

5-6) `O(N*log(size() + N))`, where N is the number of elements to insert.

### [edit] See also

emplace (C++11) | constructs element in-place (public member function) [edit]
emplace_hint (C++11) | constructs elements in-place using a hint (public member function) [edit]

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