bool empty() const; Checks if the container has no elements, i.e. whether begin() == end(). Parameters (none). Return value true if the container is empty, false otherwise. Exceptions (none) (until C++11) noexcept specification: noexcept (since C++11) Complexity Constant. Example The following code uses empty to check if a std::multimap<int, int> contains any elements: #include <map> #include <iostream> #include <utility> int main() { st

iterator begin(); const_iterator begin() const; const_iterator cbegin() const; (since C++11) Returns an iterator to the first element of the container. If the container is empty, the returned iterator will be equal to end(). Parameters (none). Return value Iterator to the first element. Exceptions (none) (until C++11) noexcept specification: noexcept (since C++11) Complexity Constant. Example See also end cend returns an iterator to the end (publ

void clear(); Removes all elements from the container. Invalidates any references, pointers, or iterators referring to contained elements. May invalidate any past-the-end iterators. Parameters (none). Return value (none). Exceptions (none) (until C++11) noexcept specification: noexcept (since C++11) Complexity Linear in the size of the container. See also erase erases elements (public member function)

Defined in header <map> template< class Key, class T, class Compare = std::less<Key>, class Allocator = std::allocator<std::pair<const Key, T> > > class multimap; Multimap is an associative container that contains a sorted list of key-value pairs. Sorting is done according to the comparison function Compare, applied to the keys. Search, insertion, and removal operations have logarithmic complexity. The order of the key-value pairs who

size_type count( const Key& key ) const; (1) template< class K > size_type count( const K& x ) const; (2) (since C++14) 1) Returns the number of elements with key key. 2) Returns the number of elements with key that compares equivalent to the value x. This overload only participates in overload resolution if the qualified-id Compare::is_transparent is valid and denotes a type. They allow calling this function without constructing an instance of Key. Parameters

move_iterator(); (1) explicit move_iterator( Iterator x ); (2) template< class U > move_iterator( const move_iterator<U>& other ); (3) Constructs a new iterator adaptor. 1) Default constructor. current is value-initialized. Operations on the resulting iterator have defined behavior if and only if the corresponding operations on a value-initialized Iterator also have defined behavior. 2) current is initialized with x. 3) Copy constructor. The underlying it

Defined in header <iterator> template< class Iterator > class move_iterator; (since C++11) std::move_iterator is an iterator adaptor which behaves exactly like the underlying iterator (which must be at least an InputIterator), except that dereferencing converts the value returned by the underlying iterator into an rvalue. If this iterator is used as an input iterator, the effect is that the values are moved from, rather than copied from. Member types Member type

Iterator base() const; Returns the underlying base iterator. Parameters (none). Return value The underlying iterator. Exceptions (none). Example See also operator*operator-> accesses the pointed-to element (public member function)

/*unspecified*/ operator[]( difference_type n ) const; (since C++11) Returns a reference to the element at specified relative location. Parameters n - position relative to current location. Return value An rvalue reference to the element at relative location, that is, std::move(current[n]). Examples See also operator*operator-> accesses the pointed-to element (public member function)

move_iterator& operator++(); (1) move_iterator& operator--(); (2) move_iterator operator++( int ); (3) move_iterator operator--( int ); (4) move_iterator operator+( difference_type n ) const; (5) move_iterator operator-( difference_type n ) const; (6) move_iterator& operator+=( difference_type n ); (7) move_iterator& operator-=( difference_type n ); (8) Increments or decrements the iterator. 1-2) Pre-increments or pre-decrements