<map> functions
The latest version of this topic can be found at <map> functions.
swap
Exchanges the elements of two maps.
template <class key, class T, class _Pr, class _Alloc>
void swap(
map<Key, Traits, Compare, Alloctor>& left,
map<Key, Traits, Compare, Alloctor>& right);
Parameters
right
The map providing the elements to be swapped, or the map whose elements are to be exchanged with those of the map left.
left
The map whose elements are to be exchanged with those of the map right.
Remarks
The template function is an algorithm specialized on the container class map to execute the member function left.swap( right). This is an instance of the partial ordering of function templates by the compiler. When template functions are overloaded in such a way that the match of the template with the function call is not unique, then the compiler will select the most specialized version of the template function. The general version of the template function, template < class T> void swap( T&, T&), in the algorithm class works by assignment and is a slow operation. The specialized version in each container is much faster as it can work with the internal representation of the container class.
Example
See the code example for member function map::swap for an example that uses the template version of swap.
swap
Exchanges the elements of two multimaps.
template <class key, class T, class _Pr, class _Alloc>
void swap(
multimap<Key, Traits, Compare, Alloctor>& left,
multimap<Key, Traits, Compare, Alloctor>& right);
Parameters
right
The multimap providing the elements to be swapped, or the multimap whose elements are to be exchanged with those of the multimap left.
left
The multimap whose elements are to be exchanged with those of the multimap right.
Remarks
The template function is an algorithm specialized on the container class map to execute on the container class multimap to execute the member function left.swap ( right). This is an instance of the partial ordering of function templates by the compiler. When template functions are overloaded in such a way that the match of the template with the function call is not unique, then the compiler will select the most specialized version of the template function. The general version of the template function, template < class T> void swap( T&, T&), in the algorithm class works by assignment and is a slow operation. The specialized version in each container is much faster as it can work with the internal representation of the container class.
Example
See the code example for member function multimap::swap for an example that uses the template version of swap.