STL: set相关算法

本节的四个算法所接受的set,必须是有序区间（sorted range）,元素值可以重复出现。也就是说，他们可以接受STL的set/multiset容器作为输入区间。

set_union

Unites all of the elements that belong to at least one of two sorted source ranges into a single, sorted destination range, where the ordering criterion may be specified by a binary predicate.

template<class InputIterator1, class InputIterator2, class OutputIterator>
   OutputIterator set_union(
      InputIterator1 _First1, 
      InputIterator1 _Last1,
      InputIterator2 _First2, 
      InputIterator2 _Last2, 
      OutputIterator _Result
   );
template<class InputIterator1, class InputIterator2, class OutputIterator, class BinaryPredicate>
   OutputIterator set_union(
      InputIterator1 _First1, 
      InputIterator1 _Last1,
      InputIterator2 _First2, 
      InputIterator2 _Last2, 
      OutputIterator _Result,
      BinaryPredicate _Comp
   );

set_intersection

Unites all of the elements that belong to both sorted source ranges into a single, sorted destination range, where the ordering criterion may be specified by a binary predicate.

template<class InputIterator1, class InputIterator2, class OutputIterator>
   OutputIterator set_intersection(
      InputIterator1 _First1, 
      InputIterator1 _Last1,
      InputIterator2 _First2, 
      InputIterator2 _Last2, 
      OutputIterator _Result
   );
template<class InputIterator1, class InputIterator2, class OutputIterator, class BinaryPredicate>
   OutputIterator set_intersection(
      InputIterator1 _First1, 
      InputIterator1 _Last1,
      InputIterator2 _First2, 
      InputIterator2 _Last2, 
      OutputIterator _Result,
      BinaryPredicate _Comp
   );

set_difference

Unites all of the elements that belong to one sorted source range, but not to a second sorted source range, into a single, sorted destination range, where the ordering criterion may be specified by a binary predicate.

template<class InputIterator1, class InputIterator2, class OutputIterator>
   OutputIterator set_difference(
      InputIterator1 first1, 
      InputIterator1 last1,
      InputIterator2 first2, 
      InputIterator2 last2, 
      OutputIterator result
   );
template<class InputIterator1, class InputIterator2, class OutputIterator, class BinaryPredicate>
   OutputIterator set_difference(
      InputIterator1 first1, 
      InputIterator1 last1,
      InputIterator2 first2, 
      InputIterator2 last2, 
      OutputIterator result,
      BinaryPredicate comp
   );

set_symmetric_difference

Unites all of the elements that belong to one, but not both, of the sorted source ranges into a single, sorted destination range, where the ordering criterion may be specified by a binary predicate.

template<class InputIterator1, class InputIterator2, class OutputIterator>
   OutputIterator set_symmetric_difference(
      InputIterator1 _First1, 
      InputIterator1 _Last1,
      InputIterator2 _First2, 
      InputIterator2 _Last2, 
      OutputIterator _Result
   );
template<class InputIterator1, class InputIterator2, class OutputIterator, class BinaryPredicate>
   OutputIterator set_symmetric_difference(
      InputIterator1 _First1, 
      InputIterator1 _Last1,
      InputIterator2 _First2, 
      InputIterator2 _Last2, 
      OutputIterator _Result,
      BinaryPredicate _Comp
   );